draft_langtou emp_170912

September 2012

ENVIRONMENTAL MANAGEMENT PLAN FOR THE LANGTOU RIVER AT HERBERTSDALE,

SOUTHERN CAPE

DRAFT for COMMENT

Prepared by

Charl de Villiers (Certified EAP) Liz Day PhD; Pr Nat Sci

Charl de Villiers Environmental Consulting Freshwater Consulting [email protected] [email protected]

Environmental Management Programme for the Langtou River – 2012 First Draft

1 Freshwater Consulting Group and Charl de Villiers Environmental Consulting

TABLE OF CONTENTS

1 INTRODUCTION 4

1.1 Background 4 1.2 Location of the Langtou River 5 1.3 Aims of the River Environmental Management Programme 5 1.4 Document structure 6

2 FINDINGS OF THE BASELINE REPORT 8

2.1 Approach 8 2.2 Describing the system 8

2.2.1 What is a wetland ? 8 2.2.2 Different wetlands in the Langtou catchment 9 2.2.3 What services can wetlands in the catchment provide? 11 2.2.4 What has happened to rivers and wetlands in the Langtou catchment ? 12

2.3 Drivers of change from reference condition 13 2.3.1 Implications of wetland/river degradation for landusers 20 2.3.2 Maintenance/repair activities undertaken by landowners in response to and in addition to large-scale

erosion 20 3 LEGAL CONTEXT OF ACTIVITIES TAKING PLACE IN THE LANGTOU CAT CHMENT 22 4 OBJECTIVES OF THE RIVER ENVIRONMENTAL MANAGEMENT PLAN 31

4.1 Management philosophy 31 4.2 Structure of the management plan 31 4.3 Overarching Management objectives 32 4.4 Strategy for achieving the four key Management Objectives (MOs) Error! Bookmark not defined. 4.5 Implementation strategy 44

5 ACTIVITY-BASED BEST PRACTICE MEASURES ERROR! BOOKMARK NOT DEFINED. 6 LEGAL IMPLICATIONS OF MANAGEMENT PRACTICES 45 7 MONITORING OPTIONS ERROR! BOOKMARK NOT DEFINED. 8 REFERENCES 62



ACRONYMS

CBA Critical Biodiversity Area

DWA Department of Water Affairs

DEADP Department of Environmental Affairs and Development Planning

EIA Environmental Impact Assessment

EMP Environmental Management Programme

ESA Ecological Support Area

FEPA Freshwater Ecosystem Priority Areas

NEMA National Environmental Management Act

NFEPA National Freshwater Ecosystem Priority Areas

NWA National Water Act

PES Present Ecological State

WCDA Western Cape Department of Agriculture



GLOSSARY OF TERMS

To be completed



1 INTRODUCTION

1.1 Background

The Herbertsdale area of the Western Cape is

primarily an agricultural area, which lies in the

catchment of the Langtou River. During recent

years, extensive flood damage has occurred in

the region, prompting local landowners as well

as various governmental departments to

instigate various ad hoc repair and

containment measures, including replacement

and /or repair of damaged bridges, drifts and

weirs, stabilising of eroded banks and

channels, removal of flood debris and

sediments and attempts to control river flows

and minimise the likelihood of further losses

to infrastructure and farming areas.

Many of these measures, as well as some

long-standing, routine approaches to

agricultural and other activities in the area, do

however constitute triggers for application for

authorisation from the Department of

Environmental Affairs and Development

Planning (DEADP) in terms of the National

Environmental Management Act (Act 107 of

1998) (NEMA) as well as from the Department

of Water Affairs (DWA) in terms of the

National Water Act (Act 36 of 1998) (NWA).

Recognising the urgent need for strategic

environmental guidance to agricultural land

use and other activities in the Langtou

catchment, as well as the fact that such

circumstances were by no means unique to

the Herbertsdale agricultural areas, Agri Wes-

Cape and the Table Mountain Fund jointly

funded the compilation of an Environmental

Management Programme (EMP), intended to

guide local landowners and authorities on

practical, ecologically sustainable practices for

implementation within the Langtou

catchment.

The EMP was intended to address ongoing

river maintenance activities such that, if

approved by DEADP, their implementation

would be deemed to be in compliance with

BOX 1 – PHASE 2 OF THE LANGTOU RIVER PROJECT

(ZA5154.1): AGREED OUTPUTS

• A baseline ecological survey is prepared and documented,

including ecological classification of the Langtou River,

mapping land-cover and land uses, and identifying

distinctive environmental features associated with the

Langtou River, its morphology and stream flow

characteristics.

• Agreed river management objectives are identified and

documented through a stakeholder-driven process;

• River management guidelines and environmental

assessment criteria for activities affecting the Langtou

River are prepared using participatory and consultative

means, and documented;

• River-related farming and conservation activities, that

have been screened in terms of the agreed management

objectives and environmental assessment criteria, are

documented;

• Following from the latter output, three classes of activities

that require environmental authorisation will be

identified, viz:

� Applications for rectification of unauthorised

activities (section 24G)

� Pre-emptive applications in relation to anticipated

flood damage

� New applications for improved in-channel

infrastructure and soil conservation works in

support of river management priorities

• A monitoring protocol is designed with CapeNature for:

o General monitoring of river health; and

o Post-maintenance/post-construction monitoring of

the riparian environment.

• A strategic river management plan with guidelines for

maintenance, construction and general agricultural use of

the Langtou River is prepared and presented with the

monitoring protocol to the stakeholder group for

approval;

• Formulation of a draft implementation plan

• Presentation of the project at at least one Conference

such as IAIAsa or Fynbos Forum

• Mainstreaming the findings of the project to DEA&DP and

other competent authorities in an attempt to streamline

and improve overall environmental management of

sensitive riparian and river ecosystems.



NEMA. The EMP was also intended to provide guidelines as to activities that do not fall into

the ambit of ongoing river maintenance, and would thus require separate authorisation by

DEADP, as well as those requiring separate authorisation by the Department of Water

Affairs (DWA).

The recommendations made in the EMP were informed by the findings of an initial pilot

study, carried out on a portion of the Langtou River near Herbertsdale, as documented in De

Villiers and Bothma (2010), as well as those of the more detailed Baseline Ecological Study

of the Langtou catchment as a whole, with a particular focus on the Langtou River. The

baseline ecological study was based on site assessments carried out in August 2011, and

reported on in Day (2012). The latter document should be referenced for any details as to its

major findings, descriptions of biophysical or ecological processes in the catchment and

their ecological and other implications. The findings of the Baseline Report underpin the

recommendations and management strategy presented in the present document.

The present report comprises the Langtou River EMP itself. This is the first draft of the EMP,

and is intended for comment and by local and other stakeholders and Interested and

Affected Parties (I&APs).

1.2 Location of the Langtou River

The Langtou River is located in the Western Cape, in the Gouritz Water Management Area.

The closest settlement is the small town of Herbertsdale, which lies just west and inland of

Mossel Bay. Figure 1.1 shows the location of the Langtou River system, in the context of the

Gouritz River, of which it is a minor tributary.

1.3 Aims of the River Environmental Management Programme

The Langtou River EMP is intended to fulfil the following objectives:

• to provide effective, feasible recommendations regarding Best Practice measures to

be implemented along the Langtou River and in the broader catchment as a whole,

so as to sustain agricultural activities without ongoing loss of land to erosion, and

loss of important biodiversity areas

• to improve the ecological status of, and reduce ongoing threats to, areas of

ecological significance

• to facilitate communication between environmental and agricultural agencies and

the landusers and others engaged in day-to-day or ad hoc activities that affect river

and wetland function and/or condition, and impact on the sustainability of

agricultural activities in the area

• to facilitate legal compliance by farmers and others engaged in activities affecting

rivers and wetlands in the Langtou catchment



Figure 1.1 GOOGLE image showing the location of the Langtou River. Not all drainage lines highlighted.

1.4 Document structure

TO COMPLETE LATER!



Figure 2.1 Major sub -catchments of the Langtou River.



2 FINDINGS OF THE BASELINE REPORT

2.1 Approach

The baseline report assessed the Langtou catchment from the perspective of its major

subcatchments, namely (as shown in Figure 2.1):

• the Palmiet River subcatchment

• the Dwars River subcatchment

• the upper Langtou River catchment

• the main stem of the Langtou in its middle and lower reaches downstream of the Dwars

River confluence

• minor tributaries of the lower Langtou.

2.2 Describing the system

2.2.1 What is a wetland ?

There are two definitions for rivers and wetlands that apply to this EMP. The first is provided

by the National Water Act and the second the South African National Wetlands

Classification.

The National Water Act (Act No. 36 of 1998) (NWA) provides the only legislated definition of

rivers and wetlands in South Africa, namely:

Wetlands are defined as “land which is transitional between terrestrial and aquatic systems,

where the water table is usually at, or near the surface, or the land is periodically

covered with shallow water and which land in normal circumstances supports, or

would support, vegetation adapted to life in saturated soil.”

Rivers fall within the definition of watercourses, defined as follows:

(a) a river or spring;

(b) a natural channel in which water flows regularly or intermittently;

(c) a wetland, lake or dam into which, or from which, water flows; and

(d) any collection of water which the Minister may, by notice in the Gazette declare to

be a watercourse.

Reference to a watercourse includes, where relevant, its bed and banks.

In terms of the above definitions, the freshwater ecosystems in the Langtou River

catchment are defined as watercourses – they comprise wetlands through which water

flows.

In contrast to the above, the South African National Wetland Classification (SANBI 2009)

defines wetlands differently to that of the NWA, stating that:

Wetlands are “areas of marsh, peatland or water, whether natural or artificial,

permanent or temporary, with water that is static or flowing, fresh, brackish or salt,

including areas of marine water the depth of which at low tide does not exceed ten

metres”.



Thus wetlands include all surface aquatic systems, including rivers and marine areas down

to depths of 10m.

In terms of this definition, the freshwater ecosystems of the Langtou catchment would all be

classified as wetlands, and the channel and its associated wetlands would be classified as

different wetland types.

The National Wetland Classification definition is considered more useful if one is trying to

unpack/address the major drivers of different freshwater ecosystems. When legal

compliance issues arise, the NWA definitions are more appropriate.

2.2.2 Different wetlands in the Langtou catchment

Most wetlands in the Langtou catchment comprise channelled valley bottom wetlands. In

their natural (or reference) condition, they are broad swathes of wetlands, that spread

across the valley floor. They are fed by flows from upstream, as well as by lateral seepage

from wetlands on the hillside and mountain slopes, known as hillslope seep wetlands.

Most of the larger valley bottom wetlands (e.g. the Langtou, the Dwars and the Palmiet

Rivers) are referred to as sandstone fynbos valley bottoms, after the natural vegetation

type they support. Wetlands in the drier areas of the catchment (e.g. just east of

Herbertsdale) are referred to as renosterveld valley bottom wetlands and/or rivers. They

tend to be much smaller systems.

Single or multiple channels braid (weave) through the valley bottom wetlands. There is a

concept among some landowners that these channels are in fact ‘the river’. When the

wetland is eroded away, or invaded by aliens, and the channel section widens, there is a

belief that the river has widened. In fact, the channel and the wetland are part of the same

system, and need to be treated as a unit, if their management is to be sustainable.

Photos 2A to 2D provide examples of wetlands in the Langtou catchment that are still

largely in a near-natural condition, and illustrate how the system functions.

Photo 2A Reference condition (Sandstone fynbos) channeled valley bottom wetland along the Palmiet River, August 2011. Alien invasion is the major impact in these reaches. The arrow shows the width of the wetland/river system.



Photo 2B Narrow channel (arrowed) through valley bottom wetland. The channel and associated wetland vegetation are both integral parts of the same system.

Photo 2C Hillslope seep (arrowed) entering wide valley bottom wetland – Palmiet River, Langtou catchment, August 2011

Photo 2D Impacted example of drier region renosterveld valley bottom wetland in the Langtou catchment, showing grazing, trampling effects, loss of indigenous vegetation and alien invasion encroachment. Wet season photo (August 2011). Wetland width is arrowed – it is much narrow than the Sandstone fynbos systems.



2.2.3 What services can wetlands in the catchment provide?

Where wetlands are in good enough condition to function in a natural or near-natural

manner, they are able to perform a number of functions of potential benefit to humans in

the catchment. Those that are potentially performed by the river/wetland systems in the

Langtou catchment include the following:

• Floodplain attenuation

Wetlands provide space for floodwaters to over-top channels that allows floodwaters to

spread without incurring high levels of erosion and loss of infrastructure – this function

assumes that the floodplain wetlands are well-vegetated with wetland suitable for periodic

flooding, and thus not liable to erode. Photos 2E and F compare the efficacy of floodplain

attenuation in indigenous wetland vegetation, as opposed to alien trees.

Photo 2E Cliffortia strobolifera re-sprouts vertically from flattened branches, showing adaptations to flood disturbance ; the plants are low growing and flatten easily, and although they slow flood velocities, they do not impede flood waters sufficiently to create downcutting

Photo 2F Invasive trees along the wetland edge impede bank overtopping, and lead to downcutting and eventual destruction of natural valley bottom wetlands

• Erosion control:

Well-vegetated wetlands can prevent erosion by reducing scour and binding soils; areas that

have been cleared, that receive concentrated runoff from roads or drainage trenches, or

where surface or flood flows are concentrated between dense alien vegetation with little

understorey growth are prone to erosion.

• Sediment trapping

Flood waters often carry sediment, which has eroded from upstream areas or which has

been mobilised from the channel by stronger flows. When floodwaters pass through

wetlands, the flow velocities decrease, as a result of the water spreading out across a wider,

shallow extent, with a significantly increased surface roughness per volume of water.

Slowing down of flows results in sediment deposition in the wetland, rather than against

bridges and roads in downstream areas.

Unfortunately, one of the effects of excessive sedimentation in wetlands is that is often

colonised by alien trees (e.g. Acacia mearnsii/Black Wattle), which leads to channel



Box 1 : Sources of Nutrients

The main sources of phosphorus- and

nitrogen-based nutrients in the Langtou

catchment are believed to be:

• Runoff from fertilised agricultural

land

• Runoff from pastures

• Runoff from feedlots

• Localised areas where livestock have

access to watercourses.

narrowing and can again speed up flows.

• Phosphate removal/trapping

A large proportion of the phosphorus load

carried by rivers binds to sediment, and is

downstream along with sediment during floods.

Wetlands that are effective at trapping

sediment are also effective, therefore, at

trapping phosphorus. When phosphorus is not

held in wetland sediments, it can accumulate in

lakes and dams in downstream areas, where it

causes algal growths and excessive growth of

reeds and aquatic weeds (e.g. water hyacinth).

• Nitrate removal/uptake

Wetlands may play some role in removal of nitrogen based nutrients from stream flows.

However, since saturated wetland soils are often low in oxygen, and oxygen is required for

the conversion of ammonia nitrogen to nitrites and then nitrates, floodplain wetlands are

not always the best tool for addressing nitrogen removal.

• Toxicant removal/uptake

Toxic chemicals contained in pesticides and herbicides used in agricultural areas can be

bound to sediments, and trapped in wetland soils, protecting water quality in downstream

systems – this is important where rivers are used as sources of water for people or livestock.

• Areas for grazing and cultivation

Wetlands and floodplain areas lend themselves to the provision of areas for grazing and

cultivation. It must be recognised however that such uses inevitably come at ecological cost,

and would not be desirable in areas managed primarily from a conservation perspective.

However, where management of systems is not carried out with a conservation and/or

restoration objective, these areas present opportunities for long-term use, provided that

sustainability is a key criteria in determining the extent of use.

2.2.4 What has happened to rivers and wetlands in the Langtou catchment ?

The major findings of the Baseline Report for the Langtou Catchment (Day 2011) can be

summarised as follows:

• Existing conservation plans (e.g. CAPE FInescale Planning and National Freshwater

Ecosystem Priority Area (FEPA) maps) represent most of the valley bottom wetlands in

the catchment as being in a Present Ecological State or condition of Class A/B, indicating

near natural conditions. Ground truthing of the catchment showed however that:

o these maps considerably over-estimate the extent of valley bottom wetlands

o moreover, most of the valley bottom wetlands included in the above maps have

been destroyed by erosion, and recovery to anywhere near to reference

conditions is considered highly unlikely

o only a small section of wetlands remain in a class A/B condition in the Palmiet



River sub-catchment, and possibly in the Goliath River sub-catchment (not

assessed in detail in the Baseline Report)

o Of the remnant A/B wetlands in the Palmiet River sub-catchment, all are

threatened by active headcut erosion, and at least two thirds of the wetlands

present in 2005 had been destroyed already by these headcuts by late 2011.

o A substantial component of the FEPA and Finescale conservation plans for this

wetland type does not in fact therefore exist, and cannot be assumed to be

contributing towards meeting conservation targets.

• The remaining, impacted wetland and river systems require significant intervention, in

order to address ongoing, rampant erosion that threatens not only instream ecological

processes, but also impacts on adjacent land users, giving rise to large-scale erosion of

floodplains, loss of infrastructure, and damage to property.

• Associated with erosion is sedimentation of downstream areas.

• Other issues that need to be considered are abstraction rates and (to a lesser extent)

water quality impacts.

2.3 Drivers of change from the reference or natural condition

The interpreted photographs shown in Photos 2G to 2Z attempt to illustrate, in concept, the

kinds of processes that have initiated or exacerbated the devastating cycles of erosion in

evidence in the Langtou catchment at the time of compilation of the Baseline Report.

The Baseline Report acknowledged that the causes of erosion are likely to be complex and

often inter-related. The following issues, illustrated as far as possible in the accompanying

photographs and diagrams, were however seen as the most likely causes of erosion, and

promoters of ongoing erosion in the systems:

• Headcut erosion – often linked to erosion in downstream systems, road or track

crossings, headcut erosion occurs when the gradient of the channel increases in one

area, with the headcut working its way upstream, sometimes in cycles, downcutting into

the channel bed and potentially drying out adjacent wetland areas as they are separated

from the lowered water table in the channel; this makes them more vulnerable to

burning and prone to erosion during floods;

• Channel constriction by alien trees, resulting in increased velocities within the channel

during floods and potential erosion of the channel;

• Obstructions to flow as a result of felled alien trees, left or washed into the channel or

floodplain – blockages, particularly against culverts and bridges, result in concentration

of flows through unobstructed areas, sometimes leading to floodwaters being diverted

onto the river or wetland banks, and causing erosion around impeding structures;

• Erosion of cleared areas, or areas where marginal wetland vegetation has been eroded,

removed or grazed;

• Poorly controlled management of runoff from roads, resulting in channel incision in

downstream reaches of culverts, pipes and channels, as a result of concentration of

flows – this can trigger headcut erosion;



• Poor bridge design, resulting in concentration of flows into downstream reaches,

upstream sedimentation and changes in sediment transport rates;

• Inadequate attention to the sizing of culverts in a (now, as a result of erosion) sediment-

dominated system, resulting in structural failure and erosion of banks; build-up of flood

debris, contributing to overtopping of bridge structures and further erosion and

damage;

• Localised disturbance to flows as a result of drifts, causeways and other crossings;

• Protection of floodplain infrastructure by floodplain infilling and stabilisation, resulting

in reduced flood capacity, increased flow velocities downstream, and further erosion;

• Protection of in-channel infrastructure (e.g. irrigation sumps) with berms and other

structures, that change the flow in the channel during flood conditions, again

exacerbating erosion of banks and other areas;

• Large-scale loss of wetland vegetation from the channels as a result of ongoing erosion,

leading to a fundamental change in the characteristics of the aquatic systems, from

wetland- to channel-dominated;

• Increased flood magnitudes, possibly in part as a result of climatic change but largely

due to a cycle of increasing channel erosion resulting in faster flows of higher

magnitude.



Photo 2G A small access track across the wetland resulted in rapid erosion of the entire wetland from these reaches of the Palmiet River. As the wetland cut downwards, so flows were more constrained, velocities increased and downcutting continued; with channel depth, so wetlands on either side dried out, making them more eorion-prone (see Photo 2H.

Photo 2H Cycle of downcutting, wetland collapse and lowering of the local water table as a result of early stages of the headcut erosion seen in Photo 2G

Photo 2I Sediment accumulates on flatter portion of valley downstream of Photo 2G. Sediment lends itself to alien invasion, which results in channel constriction, exacerbating erosion. This has occurred in the lower reaches of the Palmiet River, as well as the Langtou River upstream of the Langfontein Bridge

Photo 2J In some reaches, headcut erosion is eventually stabilised by rock sill or other structure. This photo shows stabilisation of a second headcut in the Palmiet River downstream of the drift. This headcut cause by drop in bed level of Langtou River, as a result of erosion at the confluence (see Photo 2K)

Photo 2K

Scour (see Photo 2K) may be caused by extreme natural (possibly related to climate change) flood events and/or increased flows from upstream areas that have lost wetland vegetation through headcut erosion (e.g. caused by crossings or drainage channels that trigger erosion); such flows, passing through areas constricted by alien invasion and/or further constricted by inadequate bridges/culverts and/or felled alien trees, left in the channel or floodplain, all trigger channel and bank erosion.



Scoured valley bottom wetland downstream of headcut on the Langtou River, showing alien invasion along channel edges and remnant, incised valley bottom wetland vegetation. The base of the wetland/channel is now at a lower level – sparking headcuts in tributaries such as the Palmiet River.

See Figure 3.

Photo 2L Accumulation of flood debris on alien saplings in the upper reaches of the eroded Langtou sub-catchment – large debris (sometimes left after alien felling) causes obstructions to flow and increases erosion

Photo 2M Remnant valley bottom wetland (vegetation largely lost but wiuth minimal erosion) and relatively intact floodplain just downstream of Photo 2K – but in area where alien invasion is controlled, allowing floodwaters to spread out across floodplain, and deposit sediment.

Photo 2N Sand bars developing upstream of obstructions to flow in the upper Langtou River – such sand bars lend themseves to rapid colonisation by alien seed.

Photo 2-0 Poor alignment of roads along and across seepage and other drainage lines results in daylighting of subsurface seepage, diversion of flows out of wetlands or natural water courses, and erosion, affecting infrastructure and wetland integrity and potentially triggering erosion



Photo 2P Structural failure of the Dwars River bridge as a result of erosion, both from poorly managed road runoff, as well as from scour and bank undercutting. Bridge design is not considered wide enougfh and spread of dissipated flows into downstream reaches has not been achieved

Photo 2Q Erosion upstream of confined channel at road crossing over Dwars River. Channel confinement can precipitate downstream erosion and upstream localised bank scour.

Photo 2R Repaired drift upstream of the Langfontein Bridge on the Langtou River. Arrow indicates full, natural width of valley bottom; photo indicates channel narrowing and concentration of flows as a result of drift

Photo 2S Significant erosion of floodplain downstream of Langfontein bridge in 2011; the bridge structure (not shown here) does not span the channel/wetland effectively, is too narrow, allows debris accumulation and exacerbates downstream erosion; erosion in this area also the result of alien invasion, channel encroachment and the creation of structures such as irrigation abstraction points in the floodplain, resulting in changes in floodplain hydrology (see 2T)

Aerial photos 2T Sequence of erosion events in Langtou River downstream of Langfontein Bridge, due to combined influence of upstream erosion, alien invasion, poor bridge design and presence of bermed abstraction point in the floodplain.



Photo 2U Accumulation of debris and sediment, and bank erosion, at new bridge at Herbertsdale (looking upstream)

Photo 2V Channeled flows downstream of Herbertsdale bridge have a raised sediment transport capacity.

Photo 2W Infilling of the floodplain for flood protection increases the risk of erosion and scour downstream; infilling in response to erosion as a result of sediment-hungry waters passing through the Herbertsdale Bridge ; erosion of banks exacerbated by loss of fringing wetland vegetation

Photo 2X Protection of off channel abstraction dams results in channel straightening and constriction, and increases erosion and flooding risks downstream.

Photo 2Y Bridge in the lower reaches of the Langtou results in clear channel constriction, by not spanning full extent of wetlands. Erosion during floods is likely and has affected banks downstream. Arrow indicates attempts at erosion repair by infilling.



Figure 2.2 provides a schematic showing the cycle of erosion believed to have been initiated

in the Langtou River in the vicinity and downstream of the Langfontein Bridge. Inadequately

designed infrastructure (e.g. the main road bridges), poor management of runoff from roads

and drains, wetland constriction and concentration of flows as a result of narrow

causeways, alien invasion and subsequent clearing, infilling and stabilisation of the

floodplain, excavation of abstraction points in the floodplains and wetland channels, and

burning and grazing of wetland vegetation have all played a part in bringing the Langtou

wetlands to the critical point they are in, as identified in the Baseline Report.

Natural conditions: wetlands slow down flood flows; overtop onto floodplain in large floods

Flood flows confined to wetland by alien vegetation; high velocities result in bank scour (circled) and bed downcutting, further confining channel for future events and making ongoing

erosion of the floodplain more likely

Alien vegetation confines the wetland; there may be no erosion effects until

extreme flood event, triggered by upstream erosion or natural rainfall

cycles

Indicative alien

vegetation

Figure 2.2 Schematic drawing showing simplified sequences of potential events le ading to channel downcutting and the creation of an erosi on-prone channel and floodplain in the valley bottom wetlands of the Lan gtou Catchment. Note that in some other cases, headcut erosion may initiate c hannel erosion and downcutting.



2.3.1 Implications of wetland/river degradation for landusers

Large-scale erosion and sedimentation in the Langtou catchment have brought about

profound changes at a landscape level. Along with their devastating ecological effects, they

have also had often equally devastating implications for land-users. The most significant of

these, which this Management Plan attempts to address, can be summarised as follows:

• loss of agricultural land: large areas of floodplains, as well as the riverine wetlands

themselves, are being lost on an ongoing basis;

• loss of infrastructure: irrigation sumps, access roads and drifts are often damaged by

erosion

• loss of access to wetland resources (e.g. to irrigation abstraction points/sumps): many

in-channel and even floodplain sumps are destroyed by floods;

• loss of road access: erosion of river crossings on major routes to and from Herbertsdale

and from individual erven to the main road, as well as erosion of roads as a result of

poor drainage systems as a whole, lead to delays in transporting perishable produce to

markets and general costs as a result of unreliable access to the area.

In addition to the above issues, affecting private landowners in the area, it is also recognised

that erosion and sedimentation in the catchment have significant implications for a broader

community, including at municipal and provincial level, in terms of the cost of repair or

replacement of failed major structures (bridges) and ongoing repairs required for other

infrastructure – roads, electricity pylons and water supply system for Herbertsdale. Issues of

community safety are also raised by the extent of erosion, which has resulted in the

creation of high, undercut river banks, liable to collapse in places, and the incipient erosion

of property that in some places threatens the integrity of existing residences.

2.3.2 Maintenance/repair activities undertaken by landowners in response to and in

addition to large-scale erosion

In response to the kinds of impacts that are listed in the previous section, it is not surprising

that both reactive and pro-active management measures have been implemented by

landowners and other interested and affected parties (I&APs) in the catchment as a whole.

The most obvious measures identified in the Baseline Report comprised the following:

• Repair/re-construction of damaged roads, bridges, weirs and causeways after flood

damage – often simply replicating design flaws that resulted in structural failure in the

first instance, with little to no consultation with appropriate specialists (e.g. fluvial

geomorphologists, hydrologists, wetland ecologists)

• Creation of ad hoc river/wetland crossings after floods with little regard to management

of natural river/wetland flow processes and patterns

• Stabilising/infilling the floodplain to prevent erosion

• Clearing/burning/allowing grazing of natural floodplain and valley bottom wetland

vegetation;



• Planting or failing to remove woody alien vegetation from floodplain areas, in the belief

that this vegetation halts erosion;

• Bulldozing the channel and/or banks after floods, to create berms that reduce flooding

of the floodplain;

• Protection of abstraction sumps and pumps with berms – often constructed in-channel

or at least within the floodplain;

• Dredging or excavating sediment from the river, often after flood damage;

• Channel straightening, usually in attempts to divert floodwaters away from

infrastructure or agricultural land – this simply results in increased velocities and erosion

potential; and

• Abstraction of water from well-points or irrigation sumps in the river bed, particularly

during summer.

Most of the above activities have a common effect in terms of river function – that is, they

increase river velocities, usually as a result of constriction of the channel or floodplain

and/or interfere with natural flow direction, deflecting flows into adjacent river banks and

precipitating erosion.



3 LEGAL CONTEXT OF ACTIVITIES TAKING PLACE IN THE LANGTOU

CATCHMENT1

Rivers and wetlands play an important economic and ecological role in the lives of the

farming community around Herbertsdale and it is therefore important to know one’s legal

obligations towards the protection and sustainable use of these ecosystems.

Although this river management plan chiefly addresses agricultural use and management of

the river environment, the laws and regulations that apply to farmers are equally applicable

to government departments, municipalities and private developers. Whether you are

clearing flood debris from a ‘pompgat’, building a water treatment plant next to the river or

repairing a road bridge after a flood, the chances are very good that you will need official

permission to do so.

The Constitution of the Republic of South Africa (Act 108 of 1996) guarantees our right to

ecologically sustainable development (see box). It also entrenches the right to justifiable

economic and social development. This river management plan attempts to help the users

of the Langtou River to act in a manner that reconciles these two fundamental human rights

with their day-to-day business as farmers and custodians of an important natural resource.

With this in mind, this chapter sets out to:

− Identify the main laws that govern typical activities in and around the Langtou River;2

− Explain how to ensure that you are compliant with this legislation; and

− Recommend where you can get more information about your legal responsibilities

with respect to the river and the natural environment at large.

LAWS THAT MAY APPLY TO YOUR USE OF THE LANGTOU RIVER

There are three laws that potentially have a direct bearing on agricultural and other use of

rivers:

− The National Environmental Management Act (Act 107 of 1998);

− The National Water Act (Act 36 of 1998); and

− The Conservation of Agricultural Resources Act (Act 43 of 1983).

1 The contribution of Ms Micha Lau, LLB, LLM (Environmental Law)

1 of Smith Ndlovu Summers is gratefully

acknowledged: Tel: +27 (0) 21 424 5826/56/58 Fax: +27 (0) 21 424 5825 [email protected] [email protected] 2 By ‘Langtou River’, we also are also referring to tributaries of the Langtou and their floodplains and wetlands



The National Environmental Management Act and the Conservation of Agricultural

Resources Act are enforced through regulations that are directly relevant to farming and

rivers. General Authorisations published under the National Water Act can also be very

important.

You are strongly advised to obtain legal advice if you have any doubts about your legal

obligations. Take note that laws are revised from time to time and their requirements may

change.

THE CONSTITUTION

The Constitution lays the foundation for how we are to be governed and conduct ourselves

as a society by means of a bill of fundamental rights that can be enforced by the courts.

Besides the wide-ranging environmental

right in section 24 of the Constitution, the

Bill of Rights among others also guarantees

the rights to access to certain categories

ofinformation held by the state (section 32)

and the right to just administrative action

(section 33). Further content is given to

those rights in terms of the Promotion of

Access to Information Act (Act 2 of 2000)

and the Promotion of Administrative Justice

Act (Act 3 of 2002).

The rights to access to information and

administrative justice have a direct bearing

on procedures, decisions and activities

relating to the use, management and

protection of the natural environment and

its resources.

THE NATIONAL ENVIRONMENTAL MANAGEMENT ACT (NEMA)

NEMA is our most important environmental law. It was specifically published to give effect

to the environmental right in the Constitution. NEMA is known as ‘framework legislation’ as

it lays down principles of sustainable development that must be taken into account by all

organs of state whose actions may significantly affect the environment.

The Environmental Right (s 24, The Bill of Rights)

Everyone has the right-

(a) to an environment that is not harmful to

their health or well-being; and

(b) to have the environment protected, for the

benefit of present and future generations,

through reasonable legislative and other

measures that-

(i) prevent pollution and ecological

degradation;

(ii) promote conservation; and

(iii) secure ecologically sustainable

development and use of natural resources

while promoting justifiable economic and

social development.



This is very important as any department, municipality or other arm of the state that takes

decisions that may negatively affect the environment must be able to demonstrate that

such ‘administrative action’ was guided by the National Environmental Management

Principles (Section 2 of NEMA).

These principles require among others that:

− Human needs must be placed at the forefront of environmental management;

− The use of renewable resources must not threaten the integrity of the ecosystems of

which they are part;

− The involvement of the public in environmental governance must be promoted;

− The environment must be protected as the people’s common heritage; and

− That specific attention must be paid to environmental management in sensitive,

vulnerable, highly dynamic or stressed ecosystems such as wetlands.

Section 28 of NEMA also places a duty of care on every person whose activities may or have

caused or are causing significant environmental degradation and/or pollution to prevent

such environmental degradation and/or pollution – even where it has been authorised by

law – and, where it has occurred, to rectify or minimise it. The duty of care can be enforced

through directives issued by the competent authority. It is an offence to ignore such a

directive. Should you be issued with such a directive or a notice from the competent

authority that it intends to issue such a directive, it would be prudent to obtain advice from

an attorney with the necessary expertise.

NEMA has a number of related laws that may also may apply to agricultural use of the

Langtou River, particularly the National Environmental Management: Biodiversity Act (Act

10 of 2004). Section 52 of this law provides for the listing of threatened ecosystems or

ecosystems in need of protection and can trigger the need to obtain environmental

authorisation in terms of section 24 of NEMA for development in such a listed ecosystem (a

national list of threatened ecosystems was gazetted in December 2011). See the section

immediately below for further details. Other related laws govern the establishment and

management of protected areas, waste management, the control of atmospheric pollution

and integrated coastal management.

The EIA Regulations

NEMA is probably most widely knownfor its system of control of ‘development’ by means of

the Environmental Impact Assessment (EIA) Regulations. In theory, this system is meant to

promote sustainable development.



The Department of Environmental Affairs and Development Planning is the competent

authority which enforces NEMA in the Western Cape (see box) and issues environmental

authorisations, where required. It should be noted that certain ’development’ activities may

fall within the jurisdiction of the national Department of Environmental Affairs. This is

unlikely in relation to river management activities.

NEMA (Section 24) specifies that so-called listed activities (that are published as part of the

EIA Regulations) may not be commenced without environmental authorisation. The EIA

system rests on the following legs:

− The requirement for environmental authorisation in order to undertake a listed

activity;

− Lists of such activities (there are currently three lists);

− Procedures that must be followed when applying for environmental authorisation;

and

− Legally-binding instructions on how to undertake environmental assessments to

inform such applications and the decision of the environmental authorities.

There are no guarantees that an environmental authorisation will be issued after the

mandatory environmental assessment process has been completed. The question as to

whether an environmental authorisation will be granted depends on the impacts associated

with the proposed activities.

Whether an activity is listed or not, and on which listing notice it appears in terms of the EIA

Regulations, is mostly determined by a measurable threshold such as a specified distance

from a watercourse, the diameter of a pipe, a volume of sand, or extent of indigenous

vegetation. Phased activities that, when added together, will exceed a prescribed threshold

may not be commenced without an environmental authorisation.

There are two ‘routes’ to be followed in order to

obtain an environmental authorisation. Which

‘route’ is applicable in a particular instance will

depend on the nature of the activities to be

undertaken.

The one – the streamlined version – is the basic

assessment which applies to most of the listed

activities, as well as activities in specified

geographical areas (for example, rivers beyond

the urban edge in the Western Cape) that are

published in the EIA Regulations.

Department of Environmental Affairs

and Development Planning

Directorate: Integrated Environmental

Management (Region A1)

Private Bag X 6509

GEORGE

6530

Ph 044 805 8600

http://www.westerncape.gov.za/eng/y

ourgovernment/gsc/406/services/1153

7/10199



The other application route – ‘Scoping and EIA’— has more compulsory stages and takes

longer than basic assessments. ‘Scoping’ refers to the process of identifying issues that need

to be considered in more detail during the actual EIA. The ‘Scoping and EIA’ process relates

generally to larger and, potentially, more environmentally harmful projects such as power

stations, highways, dams and harbours.

There are a number of prescribed procedures that must be followed during an application

for environmental authorisation, regardless of the application route that needs to be

followed. These mandatory elements include public participation, consideration of

alternatives, and assessment of impacts on the natural, social and economic environments.

Specialists (e.g. a botanist, agricultural resource economist or archaeologist) may need to

undertake detailed specialist studies. An environmental management programme must be

compiled to practically address impacts identified during the environmental assessment.

There is a table at the end of this section that summarises some of the listed activities that

may be triggered with respect to farming and the Langtou River, and for which

environmental authorisation may be needed.

Owing to the complexity of regulatory procedures, and the importance of ensuring that

proposed projects are informed by all relevant environmental considerations,

environmental assessments are required to be undertaken by an appropriately qualified

environmental assessment practitioner.

Certified members of the environmental assessment profession can be contacted via the

Interim Certification Board of Environmental Assessment Practitioners of South Africa:

Interim Certification Board Secretariat

PO Box 1749

NOORDHOEK

7979

Ph/ Fax 021 789 1385

[email protected] http://www.eapsa.co.za/home.html

Maintenance plans

Since August 2010, it is possible to undertake excavations or deposit sand, gravel or rock in

rivers without having first to obtain environmental authorisation for these activities. In

order to qualify for this exception under the NEMA EIA Regulations, a management plan for



maintenance purposes must have been agreed to by the environmental authorities.3 Such a

maintenance management plan does not, however, exempt one from having to apply for

environmental authorisation if planning to expand existing infrastructure or to construct

new infrastructure such as a bridge, pump foundation or weir in a river. Such a management

plan was drawn up for flood-related maintenance activities in the Langtou River in July 2011.

The maintenance management plan for the Langtou River allows farmers – as long as they

stick to the procedures contained in the plan – to undertake the following activities without

environmental authorisation:

− Reinstate damage drifts

− Clear flood debris from irrigation sumps in the riverbed

− Protect eroded river banks

− Replace pipes and electrical cables in the channel of the river

− Clear flood debris from bridges and drifts

‘Rectification applications’

Section 24G of NEMA provides for the ‘rectification’ of listed activities that have been

commenced without environmental authorisation and are therefore unlawful. It is an

offence to commence any listed activities without first having obtained an environmental

authorisation for such activities. In addition to a fine and/or imprisonment, a person who

undertakes a listed activity without the necessary authorisation can be stopped and issued

with a notice to cease the activity and rehabilitate any the environment to the condition

that existed prior to undertaking the activity.

Section 24G provides an opportunity to apply for retrospective authorisation of the unlawful

activity. You will be required to appoint an environmental assessment practitioner to

manage the environmental assessment and public participation process. An environmental

assessment report must be submitted to the provincial environmental department, with an

environmental management programme.

You will first have to pay a compulsory administrative fine before the department will make

its decision known. This can entail authorising the activity, with or without conditions.

Alternatively, you can be ordered to cease the activity, demolish or undo the unauthorised

work, and rehabilitate any residual damage to the environment.

Even though a development has been authorised via the Section 24G process, the state can

still decide to press charges against someone who has commenced an activity unlawfully. It 3 See Activity 18 of Listing Notice, published in Government Notice R. 544 of 18 June 2010, as amended.



is a defence to such a charge if the activity was commenced in response to an emergency

and so as to protect human life, property or the environment. The ‘emergency defence’ only

applies once one has been charged, however.

Convictions under NEMA carry severe maximum penalties: either a fine of up to R5-million,

or imprisonment not exceeding 10 years, or both. Note that it is also an offence to ignore a

directive issued under Section 28 of NEMA or a compliance notice (Section 31N of NEMA).

The same maximum penalties apply as to the unlawful commencement of a listed activity.

Do not delay in consulting an environmental lawyer if you have been issued with a directive

or compliance notice.

THE NATIONAL WATER ACT

The National Water Act regulates the protection, use and governance of water resources,

including rivers, wetlands and groundwater. The Act makes provision for a Reserve, which is

the minimum amount of water that must be set aside to cater for basic human needs and

the protection of aquatic ecosystems.

Most agricultural activities that entail excavations and other earthworks in the Langtou

River would probably have to licensed in terms of Chapter 4 of the National Water Act. It is

important, however, to check with the Department of Water Affairs if such activities do not

constitute existing lawful water uses in terms of the National Water Act, in which case a

water use licence may not be necessary.

Section 21 of the Act defines water uses that have to be licensed. Two of these water uses

are directly relevant to farming and irrigation around the Langtou River, namely:

− Impeding or diverting the flow of water in a watercourse; and

− Altering the bed, banks, course or characteristics of a watercourse.4

These water uses would relate typically to the practice of bulldozing berms around

irrigation sumps in the riverbed, excavating sumps, or building drifts through the river.

Strictly speaking, these activities cannot be carried out without a water use licence (or

environmental authorisations under NEMA).

However, Section 39 of the National Water Act offers an exception to the rule in the form

of General Authorisations, in terms of which specified water uses do not require a

4 Sections 21(c) and (i) of the National Water Act 36 of 1998.



licence. One of these General Authorisations deals specifically with the activities outlined

above, namely Government Notice 1199 of 18 December 2009.5

This General Authorisation dispenses with the requirement of a water use licence if a

water user can demonstrate to the Department of Water Affairs that the diversion of

flow or alteration of the characteristics of a watercourse will not have significant

environmental impacts, and that adequate provision is made for environmental

management and rehabilitation.

Such water uses must be registered with the Department of Water Affairs. See

http://www.dwaf.gov.za/Projects/WARMS/ for more information on the registration

process.

The General Authorisation relating to the diversion of flow and alteration of watercourses

does not apply to:

− These activities when they are undertaken to rehabilitate wetlands;6 or

− If the activities are within 500 m of a wetland.

In order for this General Authorisation to benefit farmers along the Langtou River, it

would be necessary to identify wetlands in the area and to delineate and map their

boundaries. This needs to be undertaken in consultation with the Department of Water

Affairs, CapeNature and the Western Cape Department of Agriculture.

THE CONSERVATION OF AGRICULTURAL RESOURCES ACT

The Conservation of Agricultural Resources Act promotes the conservation and

sustainable use of agricultural resources – soil, water and vegetation. Its objectives

include:

− Maintaining the production potential of land;

− Combating erosion;

− Protecting vegetation; and

− Combating weeds and invader plants.

The Control Measures (Section 6) of the Conservation of Agricultural Resources are

enforced through regulations.

5 GN 1199 of 18 December 2009 – Impeding or diverting the flow of water in a watercourse [Section 21(c)] and Altering the

bed, banks, course or characteristics of a watercourse [Section 21(i)] 6 See GN 1198 of 18 December 2009, which addresses licensing exemptions with respect to wetland rehabilitation



Regulation GN R. 1048 of 25 May 1984 deals with matters such as the:

− Protection of cultivated land against erosion through the action of water;

− Use and protection of vleis, marshes, water sponges and watercourse; and

− Regulation of the flow pattern of run-off water.

These regulations among others require that soil conservation works be constructed to

control erosion by water, that watercourses be kept clear of vegetation that may obstruct

floods, and that vleis may not be drained or cultivated without a permit. The Regulations

provide for four categories of weeds and invasive plants that are subject to varying

degrees of control:

Category 1 Prohibited weeds – these include hakea, long-leaf wattle, cactuses

with spines, Spanish reed and lantana

Category 2 Plant invaders that must be controlled outside demarcated areas –

these include Black wattle, sisal, old man saltbush, beefwood, several

pine species, white and grey poplars

Category 3 Potentially problematic invasive plants, such as syringa and manatoka

Category 4 Bush encroachment in which indigenous plants such as soetdoring

become invasive because of poor veld management practices

Do not attempt to clear alien plants unless you have an appropriate alien management plan.

There are several government agencies that can provide advice on how to deal with invasive

alien plants:

Western Cape

Department

of Agriculture

The LandCare District Manager

PO Box 249

GEORGE 6530

Ph 044 803 3700

Working for Water

The Regional Manager

Private Bag X4390

CAPE TOWN 8000

Ph 021 441 2700

CapeNature


Private Bag X6546

GEORGE 6530

Ph 044 802 5300

Department of

Agriculture, Forestry

and Fisheries


PO Box 380

BELLVILLE 7535

Ph 021 948 9278

Environmental Management Plan for the Langtou River – 2012 First Draft


4 OBJECTIVES OF THE RIVER ENVIRONMENTAL MANAGEMENT PLAN

4.1 Management philosophy

This environmental management programme is aimed at finding a fair and sustainable

balance between agricultural objectives and biodiversity conservation goals.

Firstly, it is recognised that the Langtou catchment is an important agricultural area, and

supports farming communities that are intrinsically linked to the river and its wetlands.

These freshwater ecosystems are of direct benefit to agriculture (they provide water and an

arable floodplain for crops and grazing). However, agriculture is also affected by the the

Langtou River and its wetlands and changes to the hydrological regime. Floods or droughts

both bring with them sometimes dire economic consequences, some of which have

permanent implications.

Secondly, it is also recognised that areas within the Langtou catchment have high

biodiversity importance from a wetland perspective.

Although the Baseline Study found that conservation plans such as FEPA significantly over-

estimated the extent and importance of wetlands in the catchment, this is assumed to have

been largely because of the rate and scale of impacts to these systems, resulting in their

virtual complete loss over a relatively short time period.

Nevertheless, there are some remnants of relatively unimpacted wetlands in the catchment.

These are considered of extremely high conservation importance, are critically threatened

and rapidly disappearing.

Although these two landuse priorities appear at first sight to be intrinsically at odds with

each other, in practice, in the Langtou catchment at least, they are relatively compatible.

This is mainly because they affect different geographical areas, with the bulk of farming

activities occurring in the lower catchment, and the last vestiges of remnant wetlands

occurring in the upper reaches of the catchment – mainly in the upper Palmiet River

subcatchment.

In light of all of the above, the management philosophy that underpins this river

management plan is to address the dual requirements of wetland conservation, and the

ecologically sustainable yet economically viable use of and interaction with wetland

resources in an agricultural context.

4.2 Structure of the management plan

The management plan presented here is based on the philosophy of addressing both

conservation and agricultural priorities in an economically feasible and environmentally

sustainable manner.

The plan itself has a hierarchical structure, comprising the following:



• Management Philosophy: this defines the approach and underpins the management

objectives

• Management objectives: these are the overarching objectives that define the kind of

management outcome that is desired for the system and its users; conformation with

the management objectives can be used to provide guidance as to the desirability of any

activities in the catchment

• Management strategy: this is the strategy that needs to be implemented to achieve the

management objectives; it is tied in with defined management “targets” – that is,

desired, measurable outcomes

• Implementation strategy: this is in effect the “action plan”, which identifies specific

projects and implementing agencies to undertake a step-by-step process aimed at

implementing the management strategy. This part of the management plan is not

supplied in this document, and needs to be developed in collaboration with

stakeholders, once the fundamental tenets of the management objectives and strategy

have been approved

• Best practice guidelines: these comprise descriptions of the least-impacting manner of

carrying out a range of activities, many of which would normally take place regularly, or

at multiple locations. Compliance with these guidelines in applicable areas would be

implicit in any over-arching approval by DEADP for implementation of a river

management/maintenance plan without going through a Basic Assessment Process.

4.3 Overarching Management objectives

The Baseline Study attempted to tease out the main drivers of river and wetland condition,

resilience and suitability for various uses in the Langtou River catchment, and the ecological

and agricultural responses to these drivers, as summarised in Section 2. On the basis of this

information, four over-arching management objectives have been formulated, which will

form the framework against which all management, maintenance and rehabilitation

measures affecting rivers and wetlands in the catchment will need ideally to be measured.

The overarching management objectives comprise the following:

1. Halt the loss of wetlands that are of high conservation/biodiversity importance

2. Prevent the loss of valuable agricultural land, resources and infrastructure as a result

of damage through erosion, sedimentation and flooding

3. Rehabilitate areas undergoing active degradation that threatens agricultural lands,

infrastructure or the provision of ecosystem services

4. Facilitate the ongoing (sustainable) use of wetland resources for agricultural

purposes while maintaining minimal essential levels of freshwater ecosystem

function and services (that is, wetland/river systems that are in a Present Ecological

State that is better than a Category E (ie Category D or better) )



Each of the management objectives is explained below.

Management Objective 1:

Halt the loss of wetlands that are of high conservation/biodiversity importance

Rationale:

The remnant Category A/B valley bottom wetlands in the catchment are of extremely high

conservation importance, and under active threat of permanent loss through erosion. Such

losses are considered irreversible.

The fact that current conservation plans have vastly over-estimated the extent of remnant

wetland in this catchment means that conservation targets at national and regional scales

are unlikely to be met for the affected wetland types.

Focus area for management action:

Remnant valley bottom wetlands in the upper reaches of the Palmiet River and its minor

tributaries, and potentially in the upper Goliath’s River sub-catchment.

Management Objective 2:

Prevent the loss of valuable agricultural land, resources and infrastructure as a result of

damage through erosion, sedimentation and flooding

Rationale:

Valley bottom wetland and extensive areas of floodplain are being lost on an ongoing basis

to erosion, with significant costs to livelihoods, ecosystems and infrastructure, while

sediment accumulation in downstream areas is further damaging infrastructure and causing

constrictions to flooding, again triggering cycles of erosion. It is essential that further losses

are minimised.

The losses of floodplain and valley bottom wetland areas to erosion are considered

irreversible.


All areas of the catchment abutting river/wetland corridors and drainage lines, but with

particular attention to the main stems of the Dwars, Langtou and Palmiet Rivers.



Management Objective 3

Rehabilitate areas undergoing active degradation that threatens agricultural lands,


Rationale:

Floodplain and valley bottom wetland areas are irreplaceable once lost. Active rehabilitation

of areas that are under threat would improve ecosystem resilience, making it less vulnerable

to future impacts, and slowly building in a level of stability, lacking in the present situation

of ongoing large-scale disturbance. This would prevent further loss of land and

aquatic/wetland habitat, provide security for (agreed-upon) agricultural activities on the

floodplain, and reduce the wasteful expenditure of resources on ongoing ad hoc repairs of

damaged infrastructure



particular attention to the main stems of the Dwars River, the Langtou River and the Palmiet

River.

Management Objective 4

Facilitate the ongoing (sustainable) use of wetland resources for agricultural purposes

while maintaining minimal essential levels of freshwater ecosystem function and services

(that is, wetland/river systems that are in a Present Ecological State that is better than a

Category E, i.e. Category D or better)

Rationale:

Freshwater ecosystems managed in a sustainable condition are resilient against moderate

levels of impact and provide useful ecosystem services. When these areas are over-

exploited or managed in an unsustainable manner, they are more likely to degrade (e.g.

erode) in times of stress. Stressors can include natural disturbance (e.g. droughts, floods)

and anthropogenic-induced disturbance (e.g. concentration of flows or shrinkage of flood

attenuation areas as a result of poor drainage or infrastructure design, leading to (inter alia)

erosion and loss of agricultural and other lands.

Potential uses of wetland resources that need to be managed sustainably include: water

supply for irrigation and domestic use; water quality for livestock, irrigation and domestic

use; floodplain areas for agriculture and grazing.


All areas of the catchment abutting river/wetland corridors and drainage lines, but excluding

unimpacted reaches of the Palmiet and (potentially) the upper Goliath’s River, and paying


River.



5 STRATEGY FOR ACHIEVING THE FOUR KEY MANAGEMENT OBJECTIVES

Strategy for achieving Management Objective 1 (MO1):

(Halt the loss of wetlands that are of high conservation/biodiversity importance)

Focus areas: Activities ensuring wetland long-term preservation should focus on the upper

Palmiet River (upstream of the existing mapped extent of headcut erosion mapped in Day

(2011)) and potentially the upper Goliath’s River.

Targets and measurable outcomes:

• No further loss of PES Category A/B wetlands in the catchment

• Management of landuse and activities around and within existing PES Category A/B

wetlands improve wetland resilience and prevent future impacts.

Strategy:

• Identify areas in the Goliath River subcatchment where Category A/B valley bottom

wetlands still occur, and monitor them for early signs of headcut erosion, which should

be addressed as a matter of urgency

• Address active headcut erosion of valley bottom wetlands in the upper reaches of the

Palmiet River – the use of gabion weirs as energy dissipation devices is likely to be

required in this area

• Address wetland drainage and desiccation in areas already affected by headcut erosion,

but where wetlands remain in areas on either side of the headcut or upstream of it –

channel plugging is likely to be required in such areas;

• Remove potential causes of future nick-point erosion (e.g. large obstructions to flow,

such as felled alien trees in the valley bottoms, throughout the Palmiet river reaches)

• Remove alien vegetation from areas abutting wetlands where present levels of invasion

are low, and recovery from degradation associated with invasion is still possible;

• Fell and remove alien vegetation from extant wetland areas, and replant disturbed areas

where cleared slopes are steep, and likely to precipitate further erosion

• Re-establish indigenous wetland vegetation in the reaches of the river that have been

disturbed by high levels of erosion

• Provide Best Practice design guidelines that can be used in the design and

implementation of the following activities within the affected subcatchment, with

downstream extent of implementation being determined by the presence of the nearest

hydraulic break-point – that is, as far as the rocky ridge across the channel downstream

of the upper causeway on the Palmiet River:

o minor road crossings over all wetlands and other drainage lines

o road drainage systems

o culvert design and conceptual sizing

o bridge design



o causeway design

• Utilise a Basic Assessment process to assess the designs of any of the above structures

within the focus area for this Management Objective, and ensure that the design

process includes input and assessment from engineering, ecological, hydrological,

hydraulic and potentially geomorphological specialists, to ensure that the structure as

designed will not trigger headcut erosion or result in concentrations of flows into

downstream areas that will result in ecosystem degradation. The following factors must

be taken into account:

o Consider the design of any new river crossings at a catchment scale, and

implement structures that:

o do not result in adjacent bank erosion or scour as a result of obstructions;

o permit sediment transport downstream

o do not constrict downstream flows or increase downstream velocities

o do not constitute permanent barriers to the upstream movement of fish

• Monitor the implementation and operational phases of the above in the affected area,

both to ensure that erosion of important wetlands is not triggered, and to provide

timeous rehabilitation responses where necessary

• Audit road, agricultural and other drainage channels that lead into unimpacted wetlands

and that might precipitate future downcutting and erosion, and address problematic

systems in terms of Best Practice guidelines

• Apply the Best Practice Measures outlined in Section 5 to all activities being undertaken

in the focus area for this MO

• Establish a conservation ethos among landusers in affected areas, such that they have a

full understanding of river /wetland dynamics and drivers, and can act/manage their

land and activities so as to prevent future degradation.



Strategy for achieving Management Objective 2 (MO2):

(Prevent the loss of valuable agricultural land, resources and infrastructure as a result of

damage through erosion, sedimentation and flooding)

Focus areas: Activities affected by this strategy are those taking place throughout the

catchment in any areas abutting river/wetland corridors and drainage lines, but with

particular attention to the main stems of the Dwars and Palmiet Rivers, and the Langtou

River downstream of its confluence with the Palmiet River.


• No further loss of floodplain or valley bottom wetland in any areas in the catchment,

regardless of Present Ecological State

• Improved resilience of floodplain or valley bottom wetlands throughout the Langtou

catchment, measured in terms of:

o increased extent of bank cover by indigenous vegetation;

o no increase in the extent of dongas/eroded channels in subcatchments and on

floodplains;

o decreased extent of woody alien invasion on floodplain;

o no increase in the area occupied by roads, buildings, dams and irrigation sumps

on floodplains;

o river water quality

Strategy:

A The Dwars River:

• Rehabilitate existing erosion points that threaten to move up- or downstream (or that

will worsen if left unaddressed), through:

o the installation of groynes, gabion weirs or other structures as necessary,

ensuring that:

� all structures are adequately sized and tie in to either bank sufficiently to

prevent structural bypass and failure

� input is obtained from appropriate specialists regarding the design and

choice of sites for installation of structures

o the removal of large obstructions to flow, such as felled and established alien

trees from the channels

o the establishment and maintenance of appropriate wetland or riparian species

on cleared areas and on the disturbed channel bottom, focusing on the

establishment of species that are:

� locally indigenous

� hardy and cost-effective to plant out in large numbers/densities

� effective at stabilising channel banks and beds, particularly in high

flow/scour conditions



• Address the design of bridge and causeway structures that currently compromise river

/wetland integrity and cause ongoing erosion, by:

o amending the current design of all crossings with design input from appropriate

specialists, including engineering, ecological, hydrological and hydraulic

specialists

o implementing structural changes to achieve sustainable crossing points, ensuring

that as a minimum:

� structures are appropriately sized to accommodate large floods, or allow

them to pass over the structures without damage, bearing in mind issues

such as climate change, channel constriction and changes in catchment

roughness as a result of erosion, which are likely to make extreme floods

more likely and exacerbate flow velocities

� structures are appropriate to systems that have high sediment mobility as

a result of erosion and carry large volumes of debris (e.g. felled trees.

branches)

� structures extend across the full width of the channel, including its

floodplain, such that structural bypass cannot occur during large floods

� adequate measures are taken to dissipate/manage runoff from side

drains and the road itself, such that it will not precipitate bank or bed

erosion or undermining of structures

• Address the current approach to management of road runoff in the catchment, by

o auditing existing culverts/stormwater channels along the major road, and

checking for areas where active erosion occurs (the Baseline Assessment Report

should be used as a guide to the identification of some of these areas)

o implementing appropriate measures to address active erosion from roadside

channels/culverts – planting and channel shaping should be considered as

measures to manage flow velocities, as well as structural check-dams where

runoff velocities are likely to be high

• Undertake phased removal of Category I and II alien plants from within 30m of all

streams, channels and wetlands, using Best Practise Guidelines outlined in Section 5,

and prioritising removal of woody species

• Apply Best Practice measures (outlined in Section 5) to the following activities:

o alien invasion

o alien clearing practices

o road drainage systems

o bridge and culvert design and repair as a matter of urgency;

B The Langtou River:

1) Stabilise the existing cycles of flooding and erosion that are occurring throughout these

river reaches, by addressing, through interventions guided by specialist hydraulic,

hydrological, geomorphological, ecological and engineering input, along with



implementation of the Best Practice Guidelines for the relevant activities/structures (see

Section 5), the following key triggers of erosion cycles:

a. known erosion nick-points that are considered triggers of ongoing erosion

cycles – these include:

• sections of the upper reaches of the river where large trees block the

channel and create scour and bank erosion

• the location and design of existing bermed sumps that are within the

floodplain or actual channel of the Langtou River

• the design of drifts

b. the design of both the Herbertsdale and the Langfontein bridges, and

implementing, as a matter of urgency, changes to bridge design that will

reduce the various issues associated with these structures, including

(variously):

• erosion and structural undermining as a result of debris dams

• upstream sedimentation

• increased sediment transport capacity in downstream reaches

• localised bank and bed scour

• appropriate management of stormwater runoff from approach roads

2) Rehabilitation measures included in (1a) (above) should include:

a. the installation of erosion-prevention groynes or other structures as

necessary, ensuring that:

� all structures are adequately sized and tie in to either bank sufficiently to

prevent structural bypass and failure

� input is obtained from appropriate specialists regarding the design and

choice of sites for installation of structures – adequate input must be

obtained from hydrological, geomorphological, ecological and

engineering specialists in structural selection, design and selection of

installation site(s)

b. the establishment and maintenance of appropriate wetland or riparian

species on areas where alien clearing has taken place, or where erosion has

resulted in exposed wetland/floodplain soils and banks, focusing on the

establishment of species that are:

� locally indigenous

� hardy and cost-effective to plant out in large numbers/densities

� effective at stabilising channel banks and beds, particularly in high

flow/scour conditions

3) Stabilise banks where infrastructure such as existing roads and houses are threatened by

severe bank erosion (e.g. immediately upstream of Herbertsdale)

• input from hydrological, geomorphological, ecological and



engineering specialists in structural selection, design and selection of

installation site(s) should be sought in this regard

• the use of groynes should be considered, to deflect flows from

affected banks, rather than the creation of long reaches of gabion

lined banks

4) Address erosion along channelled inflows into rivers, particularly those associated with

poor management of flow velocities out of road culverts – planting and channel shaping

should be considered as measures to manage flow velocities, as well as structural check-

dams where runoff velocities are likely to be high (focus areas for these activities should

include minor tributaries entering the Langtou River from the east, in the vicinity of

Herbertsdale (e.g. the Kromme River)

5) Carry out phased alien clearing, focusing on river/wetland channels, beds and

floodplains, using the Best Practise Guidelines for this activity, as outlined in Section 5

6) Provide, as far as possible, sustainable alternatives to the following practices that

cumulatively result in reduced floodplain capacity and increased in-channel velocities:

a. channel straightening/bulldozing to divert flows from banks – attention to

establishing a robust fringe of wetland vegetation along the base of the

channel should reduce the potential for erosion of these areas

b. infilling of floodplains to prevent bank overtopping – the floodplains are, by

their nature, supposed to be overtopped during large storm events, and

infrastructure should be managed such that it is not located in areas where it

is likely to be damaged by floods, or designed such that repair of flood

damage is not costly

c. the locations of abstraction sumps (“pomp gatte”) – while these can be

located in the disturbed portions of the low flow channels of the Langtou,

they should not be constructed such that they will have an impact on surface

flows. Thus the structures should not be bermed, and should be managed

with the expectation that they will need to be repaired after floods; ideally,

such infrastructure should be located outside of the channel and within the

floodplain – again, without employment of infill, likely to precipitate erosion

in large flood events

d. protection of alien vegetation in the belief that it reduces erosion – in fact,

woody alien vegetation results in increased flood scour in adjacent areas, as a

result of reduced channel or floodplain capacity, or alterations to flow

hydraulics


in the focus area for this MO.



Strategy for achieving Management Objective 3 (MO3)

Rehabilitate areas undergoing active degradation that threatens agricultural lands,


Focus Area:



River


• An improvement in the Present Ecological State of floodplain and/or valley bottom

wetlands and rivers in the focus area, such that no system is in a PES Category E or lower

Strategy:

1) Implement the Management Strategy outlined for MO2, as this includes rehabilitation

measures aimed at

a. prevention of loss of land

b. preventing erosion along channelled inflows into rivers

2) Address headcut erosion in tributaries feeding into the Langtou River through the

implementation of the Management Strategy outlined for MO1

3) Along the Langtou River, downstream of the Palmiet River confluence:

a. Implement protected buffer strips of at least 10m width along the channel

edge of all rivers/wetlands – in the case of the Langtou River, this means the

existing, wide, eroded channel, that is currently expanding through erosion

into the floodplain

b. actively instate appropriate indigenous wetland vegetation in the channel,

along disturbed floodplain and wetland edges and within the buffer areas,

such that it can play an active role in improving floodplain protection and

long-term channel stabilisation

c. manage these areas as protective buffers, aimed at safeguarding adjacent

agricultural areas by the establishment of robust, stable riparian and wetland

zones, and at providing robust ecological corridors through the landscape

4) Along the Dwars River, upstream of the eroded road crossing, and within the constraints

of encroachment by existing infrastructure (e.g. roads), but not confined by agricultural

encroachment:

a. establish buffer areas of 720m in width along either side of the Dwars River,

and 10m along minor watercourses, seeps and other wetlands in which

neither cultivation nor grazing occurs;

b. focus rehabilitation activities on these buffer areas, including

i. bank reshaping (flattening/ grading) 7 This buffer width has been recommended with regard to the relatively steep valley slopes of the Dwars River, and should

specifically apply to the reaches upstream of the eroded bridge crossing



ii. alien clearing and removal

iii. planting with appropriate indigenous plant species

c. manage these areas as protective buffers, aimed at safeguarding adjacent

agricultural areas by the establishment of robust, stable riparian and wetland

zones, and at providing robust ecological corridors through the landscape

5) Address localised sources of pollution into the Langtou River by implementing the

following measures:

a. actively limit runoff/seepage into the river, its wetlands and groundwater by

locating manure stock piles on impervious surfaces, edged by lined cutoff

drains that lead into lined evaporation ponds rather than into the river

b. actively remove accumulated manure from livestock feedlots to limit nutrient

loading into downstream areas

c. establish more extensive setback areas between the Langtou River and its

wetlands than the minimum measures outlined in (3) (above):

� feedlots should be set back at least 50m from the wetland edge

� feedlots shoud be located outside of the 1:10 year floodline

6) Implement effective controls on the quantity of abstraction from the Langtou River, to

ensure that instream processes are maintained, and indeed improved, in the river

particularly over summer, in order to bring about rehabilitation of stabilising wetland

systems, through the following:

a. liaison with DWA regarding the need to undertake a Reserve Determination

in for the Langtou River

b. investigation of the impact of abstraction on low flows in the Langtou River

c. implementation of wetland rehabilitation and protection measures as per

MOs 1 to 3, in order to bring about improved water retention in the system

during dry periods.

7) Apply the Best Practice Measures outlined in Section 5 to all activities being undertaken

in the focus area for this MO.



Strategy for achieving Management Objective 4

Facilitate the ongoing (sustainable) use of wetland resources for agricultural purposes while

maintaining minimal essential levels of freshwater ecosystem function and services

Focus Area: All areas of the catchment abutting river/wetland corridors and drainage lines,

but with particular attention to the main stems of the Dwars River, the Langtou River and

the Palmiet River


• Effective implementation of MOs 1-3, as measured in their relative targets and

outcomes.

Strategy:

• Implement the Strategies outlined for MO1-M03


in the catchment area

• Request assessment of, and ensure implementation of, the Ecological Reserve for the

rivers in the Langtou catchment

• Compile a detailed action plan to ensure effective planning and implementation of the

management programme

• Establish an independent body with an institutional and community mandate to

implement, police and enforce the implementation of the EMP

• Source funding for/assign responsibilities for financing the different activities outlined in

the EMP

• Design and Implement a Monitoring Plan to ensure that the rehabilitation strategy is

effective and implementable in the long-term.



5.2 Urgent management priorities

The previous sections presented the management objectives that, it is believed, must

underpin the approach to landuse and all other interventions likely to affect river and

wetland function and condition in the Langtou Catchment. Each of the four management

objectives presented were accompanied by a set of (still coarse) strategies, which need to

be implemented in order to ensure that the management objectives are achieved. Some of

the objectives, it is noted, share similar strategies, the implementation of which will clearly

achieve multiple positive outcomes.

While all of the management objectives and associated strategies are considered essential,

it is also recognised that their achievement will be a lengthy process, requiring buy-in from a

broad community of landowners, employees and officials from local, provincial and national

government departments. In this context, it is useful to highlight the parts of the EMP that

should be prioritised for implementation with immediate effect, as opposed to those that

are necessary, but that may be implemented over a longer period of time.

The following activities are considered urgent management priorities:

• Establishment of an implementing body / bodies to drive the implementation of the

EMP - it is essential that all stakeholders actively engage in this process. In addition to

local landowners and communities, stakeholders that are engaged in the project must

include the Departments of Roads and Transport, Agriculture and Water Affairs, all of

which need to engage actively in rectification of the dire neglect and poor management

of the Langtou system to date;

• The prevention of further erosion of unimpacted wetlands threatened by headcuts –

MO1;

• Urgent attention to the repair and re-design of the three main bridges in the catchment,

each of which is associated with significant erosion, largely as a result of a failure to take

into account the characteristics of the affected catchment and wetland (MO2);

• Urgent attention to the removal of berms from all abstraction sumps in the eroded river

channel;

• Active rehabilitation of eroded channels through the construction of groynes, alien

removal, replanting of cleared areas, protection of river banks by limiting grazing and

creating vegetated buffer areas (MO2 and MO3) – the use of groynes and possibly

gabion stabilisation should be prioritised in the reaches of the river between the

Langefontein Bridge and the Herbertsdale bridge, with particular attention being paid to

the significant, property-threatening erosion taking place at the first drift upstream of

the Herbertsdale Bridge;

• Determination of the Ecological Reserve for the Langtou River, and the use of this

information to control abstraction rates from the river such that it is ecologically

sustainable (MO4);

• Modification of various problematic landuse practices (location and management of

abstraction points, floodplain management, livestock controls) (MO2 and MO3);

• Addressing road drainage design so that it does not precipitate erosion (MO2).



6 ACTIVITY-BASED BEST PRACTICE MEASURES

Maintenance Activity Stipulations

ALIEN CONTROL Note that this section addresses only the major alien invasive plants currently

affecting the Langtou catchment. An alien management plan needs to be drafted

for the Langtou River catchment, outlining up-to-date measures appropriate for

alien removal in the vicinity of aquatic ecosystems.

Black Wattle

(Acacia mearnsii)

.

Priority should be given to the clearing of:

• Small/sparse infestations of wetlands of high importance (e.g. upper Palmiet

system)

• Clearing of all woody alien vegetation from within 50m of channels and/or

from the river floodplain

• Upstream infestations – clearing should take place from upstream to

downstream, so that sources of propagules are systematically removed

• Adequate attention should be given to maintenance of cleared areas such that

they are not re-colonised

• Re-planting of cleared areas is an essential component of alien clearing.

Methods for clearing:

Large trees and/or Mature medium to dense stands

• Felling and burning, bulldozing/using a “Mulch Master”, herbicide stump

treatment, stump treatment with fungus, frilling, bark stripping or ringbarking,

or using biological control “Melanterius acaciae” can be used to treat this

category.

• Note that bulldozing should not be carried out in areas where its use will result

in the disturbance of river bank and/or wetland areas.

Scattered mature trees

• All the methods of eradication described above are applicable. Barkstripping

and frilling are good options for this category.

Medium and dense stands of saplings

• Trees can be felled and the stumps treated with herbicide or fungus, the slash

can be burnt (if fungus is not being applied). A stem treatment of herbicide may

be applied or bulldozer a “mulchmaster” used.




Scattered and single young trees

• The cheapest and most efficient method is to apply herbicide to the stems,

however stump treatment is also applicable.

Seedlings

• Foliar spray, handpulling or burning

Managaement of cut material (Holmes et al., 2008, p 543)

• Kill large trees standing and leave in place.

• Remove cut material and stack it away from edge of wetland and river bank.

Stacked piles must not be higher than 120 cm. Burn in wet season.

• Prevent fires in cleared areas

Frequent fires favour alien grass invasion and stimulate germination of Acacia spp

seed.

Sesbania punicea ( Biological control is most effective

Cutting promotes re-growth unless herbicide applied to cut stems

Arundo donax • Cut and remove rhizomes entirely from the soil – this plant can re-grow

from even small remnants left in the soil;

• Cut and apply appropriate herbicide

Pinus spp. (pines) Pines to be cut and removed from the floodplains, streams and wetlands

Other Species of concern: Department of Agriculture or CapeNature to be consulted regarding identification

of other problem plants in the catchment on an ongoing basis, and for

recommendations regarding effective means to control them

INFRASTRUCTURE

Maintenance of abstraction sumpsThe location of sumps, particularly those associated with berms that alter

flow patterns under flood conditions, precipitating extensive erosion, is not ecologically desirable, and there

should be a movement away from this strategy for accessing water. Abstraction rates should moreover be

informed by the findings of an Ecological Reserve Determination for the LangtouRiver, which specify minimum

flow requirements to maintain river function at a particular desired level.

Excavation of sediment

−

Location

− Keep existing abstraction sumps where they are

− If sumps are damaged by floods or clogged by flood debris and need to be re-

excavated, retain existing location unless this is not advised in terms of these

guidelines (that is, unless existing sumps are located in the channel, in which

case they should be moved into the floodplain).




− Obtain specialist input, with reference to these guidelines, if sumps need to be

moved, or if new sumps are to be excavated.

Design

− No sumps may be created in the active low flow channel

− No sumps may be located in any areas of the catchment within extant wetlands

– these wetlands have been lost from virtually the entire catchment and

require sensitive management

− Sumps should ideally not be placed in the broader eroded channel either, as

they contribute to ongoing instability of this area. A concerted effort must

therefore be made to find alternative means of abstraction from the river – the

viability of sinking well-points into the floodplain abutting the unstable channel

should be explored as a matter of urgency, as should the potential for off-

channel storage of high-flow water

o Sumps that are located in the broader eroded section of the channel:

must be treated as follows: indigenous vegetation must not be

damaged during excavationsdisturbance to the natural structure of

channels, sand and gravel banks in the river bed to be minimised – i.e.

no bulldozing beyond the boundaries of the sump

o Sumps must be dug parallel to the direction of flow – but should not be

in main channels, and no closer than 20m from the channel edge (this

allows for some channel movement without interfering with the sump)

o Sumps should not be bermed, as berms alter the flow of water across

the floodplain – the top edge of sumps should thus be level with the

ground surface - this applies to sumps on the floodplain and in the

eroded channels

o sumps should not be constructed in secondary flow pathways – these

are usually dry during baseflows but take flows during slightly elevated

flows,

−

Maintenance

− Use only one access point to the channel when maintaining sumps

− Avoid damage to indigenous vegetation

− Large debris (rocks, large branches and trees etc) excavated from clogged

sumps must be removed from the channel and deposited outside of the

channel and the floodplain




− Sand/gravel excavated from the sumps should be deposited downstream of the

sumps, spread across the floodplain or deposited on the inside bends of the

channel

− Implement all the measures relating to the location and design of sumps

Maintenance of causeways

Excavation of

sediment and

obstructions to flow

Re-instatement of

damaged causeways

− Do not rebuild or relocate flood-damaged drifts without consulting these

guidelines and obtaining advice from a river specialist

− Use only gravel and stone from the river to rebuild damaged drifts. The driving

surface may be sealed and lightly compacted with clay.

− Drifts must be packed loosely enough to allow water to filter through under

low flow conditions

− Under no circumstances may drifts be constructed with compacted material

that restricts the surface or sub-surface movement of water down the channel

− Approaches to the drift must not cause narrowing of the channel or

obstructions to floods.

− Drifts must not result in narrowing of the channel or concentration of flows

downstream of the drift

− The profile of drifts must be as low and flat as possible to prevent flows being

concentrated at any point.

− The approaches to drifts must be protected against circumvention and erosion

by flood waters. This may require gabions to be installed up- and downstream

of the two extremities of the drift. Obtain advice from a river specialist. NOTE

Any new structure, such as gabion mattresses, that are 50 m2 in extent or

greater will require prior environmental authorisation. A water use licence may

also be needed

− If there is any risk that over-topping of the drift will cause scouring downstream

of the structure, measures need to be taken to prevent this. It may be

necessary to armour the river bed downstream with a suitably wide gabion or

reno mattress. Obtain advice from a river specialist.

− The up- and downstream faces of the drift must be protected, to prevent

erosion through the drift and the creation of headcuts into upstream areas

− . Obtain advice from a river specialist. NOTE Any new structure, such as gabion

mattresses, that are 50 m2 in extent or greater will require prior environmental

authorisation. A water use licence may also be needed.

− Drifts must be equipped with drainage pipes if they are likely to submerged




deeper than 15 cm during higher flow conditions. Obtain advice from a river

specialist before installing pipes through a drift. Drainage pipes must:

o Be large enough to accommodate baseline flows

o Not concentrate flows

o Distribute flows across the full width of the channel.

− Excavations in rivers must be limited to dry periods, where possible.

− River banks disturbed during repairs or maintenance must be rehabilitated by:

o Retaining topsoil to a depth of 150 mm;

o Grading the bank to a slope not steeper than 1:4;

o Re-establishing topsoil and planting naturally occurring indigenous

pioneer plants in their appropriate niches in the river bank, with

particular attention paid to the establishment of plants at the base of

the bank, where it will exert a stabilising influence

o Keeping the rehabilitated area and surrounds clear of invasive alien

plants.

− Do not use boulders for rehabilitation as this will cause erosion and

destabilisation of the channel.

− Large debris (large branches, logs and trees only) excavated from upstream of

the structure must be removed from the channel and deposited outside of the

channel and the floodplain

− Sand excavated from upstream of the drift should be deposited downstream of

the structure, on the inside bends of the channel

− excavation of sand from upstream of structures should be limited to a zonbe no

longer than 30m in length and should not result in destabilisation of river banks

Maintenance of Bridges

− Bridges can cause a great deal of damage to rivers due to inadequate flood capacity, channel restriction,

formation of plunge pools and scouring downstream, deflection of flows into floodplains and build-up of

sediment that artificially amplifies the negative effects of small floods (i.e. with return intervals of less than

one-in-five years).

Bridge repair, removal of

sediment and debris and

stabilisation of banks and

bed

− Timeous removal of blockage of sand, gravel, stone and large plant debris

(branches, tree trunks) that impede flow underneath bridges can help to

minimise the risk of major flood damage.

− Regular inspection and maintenance of bridges and low water crossings is

therefore critical to protect the natural and agricultural environments from

otherwise avoidable flood damage.

− Large debris (rocks, large branches and trees etc) that accumulate on or against




the bridge, or immediately upstream must be removed from the channel and

deposited outside of the channel and the floodplain

− Sand excavated from bridge culverts should be deposited downstream of the

structure, on the inside bends of the channel – sand may be removed from up

to 30m longitudinal distance upstream of the structure only; machines may be

used to move the sand as specified

− Mechanical disturbance to the natural pattern and structure of the bed

(particularly subsidiary channels and sand and gravel deposits) and banks of the

river must be avoided, outside of the 30m upstream zone already allowed for.

− Use one access point to the river and rehabilitate it afterwards.

Where bridge structures result in repeated erosion of adjacent banks and/or

infrastructure failure, a fluvial geomorphologist must be consulted in collaboration

with an engineer and river ecologist to design a structure that will be more

economically and ecologically sustainable under the prevailing conditions. This

process would need to entail a Basic Assessment and/or application to DWA for a

water use licence or General Authorisation.

Replacing pipes and electrical cables in the riverbed

− Use one access point to the river and rehabilitate it afterwards.

− Minimise disturbance to the natural structure of channels and sand and gravel

banks in the river bed

− Make sure that buried pipes and cables do not cause the flow of water to be

blocked or to change direction – they must thus either be installed at depth or,

preferably, be attached to existing infrastructure such as bridges or causways

− Buried infrastructure that spans the width of the channel may not be protected

by berms

− Buried infrastructure that spans the width of the channel must not impede sub-

surface movement of water3333

− Dig trenches as narrowly as possible with minimal disturbance to the

surrounding bed and banks of the river

− Infilling of any trenches on the floodplain or in the river channel and

surrounding wetlands should be to pre-excavation levels – in the event that a

large pipe is installed, excess fill will be generated and should be disposed of




outside of any wetland rivers or the floodplain

− Re-instate and plant disturbed banks after excavation (see Rehabilitation

Methods)

Erosion repair and stabilisation

Banks

− Use only one access point to the channel when repairing or protected river

banks

− Avoid damage to indigenous vegetation

− Rehabilitate disturbed access points

− Loose material can be bulldozed against the toe of eroded river banks to angle

of slope not steeper than 1:2.

− Earthmoving activities must not obstruct the flow of water, or its direction.

− Bank repairs and stabilisation must not result in constriction of the river

channel.

− Excavations must be limited to one bank of the river and avoid, insofar as this is

feasible, protecting opposite banks with bulldozed material (gravel and rocks)

− Do not move unconsolidated material into the outside bend of rivers as this

simply worsens the effects of erosion and destabilisation of the channel.

− Under no circumstances may earthworks be used to ‘straighten’ the river

channel as this increases flow rates, erosion and destabilisation of the system.

− Excavations and earthworks may not deepen the channel or alter flows so that

down-cutting occurs.

− Excavations and earthworks must not change the alignment (direction) of the

channel.

− Do not use large rocks to protect eroded river banks as this excarbates erosion

and channel destabilisation during higher flows.

Where feasible, revegetate graded areas.

Erosion protection measures

The practice of bank protection by piling rocks, gravel, rubble and sand against the banks is ecologically

undesirable. This is because it requires extensive bulldozing of the river channel, perpetuating instability and

preventing any possibility of stabilisation by vegetation. Similarly, the practice of erosion control by channel

manipulation/straightening is unacceptable, usually increasing erosion rates and also preenting long-term

stabilisation. These practices are thuis NOT supported by the management plan.

− No bulldozing or other mechanicakl disturbance of the channel, other than




immediately upstream of drifts and bridges, and for the express purpose of

sump maintenance

− bank stabilisation must be achieved by systematic planting of the base of the

banks with wetland vegetation, that will stabilise the bank, as well as by

removal of alien vegetation in the floodplain and along the river banks, and its

replacement with appropriate indigenous riverine plants.

− Do not disturb indigenous vegetation on the banks of the river.

− Avoid mechanical disturbance and trampling by cattle to the banks and bed of

the channel.

− Remove alien vegetation according to an appropriate alien management plan.

− Revegetate disturbed and cleared areas with appropriate indigenous plants

paying particular attention to establishment of plants on the lower banks

where erosion protection is often most necessary

− Large debris (i.e. trees, big logs and large branches) that wash into the channel

must be removed and dumped or burnt well out of reach of floodwaters (ie

outside of the floodplain).

− Avoid any activities that may accelerate the rate and direction of flow of water

in the channel and into the floodplain. This includes:

o Narrowing, straightenening, filling in or deepening the channel

o Creation of berms, sumps, dams or other opbstructions in the channel

o Any obstruction in the channel that deflect water against the banks of

the river

o Poorly designed drifts and low water crossings that concentrate flows

instead of spreading them across the width of the channel

o Drifts and low water crossings that impede base flows as a result of

blockages or excessive compaction of fill

Revegetation

Planting plan

− Planting should take place at the appropriate time of year. In the Western

Cape, this period is usually late autumn, in order to catch the early light winter

rains and allow establishment of species before the onset of heavier rains. This

means that all activities, from the start of maintenance, should be planned with

this time constraint in mind

− A planting plan, specifying type, number, location and required cover of

species, should be produced prior to initiation of the programme. This should

be developed with the assistance of CapeNature or a botanist. Species should




be indigenous to the catchment.

− Planting of rooted plants is often more successful than seeding, particularly

where there is limited time for the establishment of plants

− Planted areas must be regularly monitored during the establishment phase,

and dead plants removed and replaced.

− Weeding during the establishment period should be a requirement of all

planting programmes, particularly where planting is restricted, as disturbed and

bare ground is vulnerable to establishment of weeds. Alien plant species should

be removed before planting, and should be monitored and removed

appropriately on appearance

− Allowance should be made for watering of revegetated areas through at least

one dry season

Site preparation

− Where feasible, collect topsoil to a depth of 150 mm and stockpile it for post-

maintenance rehabilitation.

− Grade banks to a slope of at least 1:4, but preferably flatter

− Grade slope downwardsAlternatively, step slope to favour re-establishment of

locally-occuring indigenous plants

Revegetation

− The objectives of revegetation are to:

o Secure bank stability

o Control soil erosion

o Maximise the diversity of natural habitats in and around the river

channel

− Revegetate disturbed areas with indigenous, locally-occurring pioneer species

at level of base flow

− Re-establishment of vegetation must entail a mix of locally occurring pioneer,

understorey (herb and shrub) species

− Use bagged plants rather than seeds or cuttings to achieve rapid stabilisation of

particularly lower banks

− Irrigate replanted areas for at least first summer of restoration programme

− Apply mulch to replanted areas and weed at least every two months for first

two years of restoration programme, then annually

− Repair and replant eroded areas during establishment phase

− Implement alien plant eradication and management programme in 1 000 m

circumference around, and between, structures




− Aim to maintain and management revegetated riparian buffer in a natural

condition



7 LEGAL IMPLICATIONS OF MANAGEMENT PRACTICES

This table summarises official permissions that may have to be obtained before undertaking specific

management actions in the Langtou and other rivers.

It is always advisable to check with the authorities which laws may apply to your proposed actions.

Contact the Department of Environmental Affairs and Development Planning for advice in this regard. NEMA EIA REGULATIONS NATIONAL WATER ACT CONSERVATION OF

AGRICULTURAL RESOURCES ACT

Compulsory basic assessment

Exemption i.t.o. approved maintenance plan

Water use licence

Exemption i.t.o. General Authorisation

Permit in terms of CARA Control Measures

Repair & reconstruction of damaged roads, bridges, weirs and causeways after floods

Yes, unless repaired/replaced structures are no different to what was there before or less than 5 m3

of sediment needs to be moved in a watercourse.

Potentially . Repairs and reconstruction must be limited to movement of sediments in river.

Probably, yes , unless repairs etc are covered by GN R. 1199 of 18-12-2009.

Potentially , if repairs are consistent with GN R. 1199 of 18-12-2009 and registered as water uses with the Dept of Water Affairs.

Potentially, yes . A permit may be necessary if repairs etc take within 10 m of a watercourse or vlei.

Creation of river/wetland crossings (drifts) after floods

Yes, unless repaired/replaced structures are no different to what was there before or work entails moving less than 5 m3 of sediment in a watercourse.

Potentiall y. Repairs and reconstruction must be limited to movement of sediments in river.

Probably, yes , unless repairs etc are covered by GN R. 1199 of 18-12-2009.

Potentially , if repairs are consistent with GN R. 1199 of 18-12-2009 and registered as water uses with the Dept of Water Affairs.


Stabilising /infilling the floodplain to prevent erosion

Yes, unless these activities are covered by an approved maintenance plan or entail moving less than 5 m3 of sediment in a watercourse

Potentially , if activities are covered by an approved maintenance plan.

Probably, yes , unless activities etc are covered by GN R. 1199 of 18-12-2009.

Potentially , if activities are consistent with GN R. 1199 of 18-12-2009 and registered as water uses with the Dept of Water Affairs.


Removal of alien vegetation from floodplain areas

Probably not , unless clearance entails bulldozing sediment in excess of 5 m3 in a watercourse.

Potentially , if clearance entails movement of sedimente that is covered by an approved maintenance plan.

Unlikely , unless alien clearance entails physical changes to the channel and banks of a watercoourse.

Unlikely to be necessary. See the General Authorisation regarding wetland rehabilitation (GN R. 1198 of 18-12-2009)

Potentially compulsory under the CARA regulations.

Bulldozing the channel and/or banks after floods to create protective berms

Yes, unless these activities are covered by an approved maintenance plan.

Potentiall y, if activities are covered by an approved maintenance plan.

Probably , yes, unless activities etc are covered by GN R. 1199 of 18-12-2009.


Potentially, yes . A permit may be necessary if earth movement takes place within 10 m of a watercourse or vlei.



NEMA EIA REGULATIONS NATIONAL WATER ACT CONSERVATION OF AGRICULTURAL

RESOURCES ACT Protection of abstraction sumps and pumps with berms






Dredging or excavating sediment from the river, often after floods damage






Excavating sediment from ‘pompgate’ and the river, often after floods


Potentially yes , if activities are covered by an approved maintenance plan.

Probably, yes, unless activities etc are covered by GN R. 1199 of 18-12-2009.



Abstraction of water from well-points or irrigation sumps in the river bed,

Unlikely unless well-point or sump needs be authorised, or another activity is triggered by a road, construction of foundations or such.

No, unless well-points or sumps are to be excavated in a watercourse.

Probably yes . See Section 21(a) of the National Water Act

No, unless abstraction entails activities covered by General Authorisation GN R. 1199 of 18-12-2009.

Potentially, yes , if establishment of abstraction point entails removement of vegetation within 10 m of watercourse or vlei.



8 MONITORING OPTIONS

The Environmental Management Plan for the Langtou River and its tributaries outlines specific measures

aimed at improving river and wetland function in reaches where these are currently unsustainable and

are resulting in loss of both land and system function on an ongoing basis, and in reaches where

remnant systems in good condition are threatened by erosion or other impacts. This section outlines a

monitoring programme, which ought to be implemented in the catchment in order to assess the impact

of implementation of the monitoring programme on aquatic ecosystems, to allow informed adaptation

of the management plan where the objectives are not being met despite implementation efforts, and to

provide a mechanism for policing whether or not the management plan is in fact being effectively

applied at a catchment level.

8.1 Components of the monitoring programme

The Monitoring Programme should incorporate the following elements:

• Monitoring of overall river and wetland condition, using Present Ecological State assessments;

• Monitoring of wetland extent, using desk-top based mapping off aerial imagery and including regular

ground-truthing of key areas;

• Monitoring of extent of alien invasion using desk-top based mapping off aerial imagery;

• Water quality monitoring;

• Monitoring of river habitat quality, as a measure of the extent to which stabilisation of the river is

taking place over time (SASS5 and IHAS);

• Monitoring of flow regime.

8.2 Components of the monitoring programme

8.2.1 Monitoring of overall river and wetland condition, using Present Ecological State assessments

Assessment of overall river condition should be based on ongoing, long-term monitoring of changes in

Present Ecological Status (PES) category for different reaches of the main wetland systems in the

Langtou catchment, using the Wetland Index of Habitat Integrity methodology of DWAF (2007). This

methodology was designed specifically for the assessment of South African floodplain and Channelled

Valley bottom wetlands.

Standard PES categories of ecosystem health are derived from this methodology, as summarised in

Table 8.1, after DWAF (2007). The actual datasheets required for completion of these assessments are

available in spreadsheet form. DWAF (2007) includes detailed guidelines for the step-by-step

assessment of different components of habitat integrity, and should be referred to where the

monitoring team is in doubt.



Table 8.1 Descriptions of PES ecological categories derived by application of the Wetland Index of Habitat Integrity for floodplain and channelled valley bottom wetlands. Categories correspond to those developed by Kleynhans (1999)

Monitoring sites: Fixed monitoring points should be as indicated in Figure 8.2, but site-based monitoring

should acknowledge that the data collected apply to whole reaches/subcatchments, and cognisance of

general river condition should thus be taken while accessing specific sites.

Monitoring personnel: monitoring should be carried out by a wetland ecologist

Monitoring frequency: every two years, at the same time of year

8.2.2 Monitoring of wetland extent, using desk-top based mapping off aerial imagery and including

regular ground-truthing of key area

• Long-term GIS-based mapping of wetland extent should take place, focusing on the upper Palmiet

catchment and (initially) on the Goliath’s catchment.

• Wetland extent/the location of erosion nick-points and channelisation areas should be identified

during on-the-ground inspections of these areas

• Fixed point photography should be employed to indicate changes in down-cutting or vegetation

extent

• Data collected should quantify aerial extent of wetlands, as well as allow overlays of polygons

showing alien extent over time, and indicate the position of head cut erosion points.

• Mapping should be carried out on a scale no smaller than 1: 2000.

Monitoring personnel: monitoring should be carried out by personnel with GIS experience in wetland

mapping; ground-truthing to be carried out by local conservationists

Monitoring frequency: every two years

Monitoring area: Upper Palmiet River catchment; upper Goliath’s catchment if it includes important

remnant wetlands.



8.2.3 Monitoring of extent of alien invasion using desk-top based mapping off aerial imagery

• Long-term GIS-based mapping of alien extent should take place on a five yearly basis, with ground-

truthing of verification by local landowners. Data collected should quantify aerial extent of invasion,

as well as allow overlays of polygons showing alien extent over time.

• Mapping should be carried out on a scale no smaller than 1: 2000.

• Mapping should indicate:

o extent of main black wattle, pine and gum stands

o extent of cultivated lands

Monitoring personnel: monitoring should be carried out by personnel with GIS experience in land-use

mapping, with verification of outputs by local landowners

Monitoring frequency: every five years.

8.2.4 Monitoring of river habitat quality, as a measure of the extent to which stabilisation of the river

is taking place over time

8.2.4.1 Water quality monitoring

Water quality monitoring should take place from the sites shown in Figure 8.1 (LT-B to E (not A) and LT-1

to 3).

At each site, in situ measurements should be taken of pH, dissolved oxygen (both concentration and

percentage saturation), electrical conductivity (EC) and temperature.

Water samples should also be collected and analysed for the following:

• Total phosphorus

• Soluble reactive phosphate (SRP)

• Total suspended solids (TSS)

• Total ammonia, measured as NH4-N

• Un-ionised ammonia (NH3)

• Nitrate and nitrite nitrogen (NO3+NO2)-N.

Monitoring personnel: trained water quality technicians – responsible members of the Herbertsdale

community may be trained in water quality sampling protocols

Monitoring frequency: ideally monthly; at least quarterly.

8.2.4.2 SASS5 Macroinvertebrate monitoring

SASS5 macroinvertebrate assessments were not carried out on site during the baseline study. That is

because the reference condition of the system is a vegetated channel rather than a channelled river.

However, in terms of long-term monitoring, SASS5 will at least allow a structured comparison of changes

in macroinvertebrate community structure and dominance, which can be related to changes in river

habitat quality over time, as well as (less usefully in the current circumstances) water quality.



SASS5 monitoring of macroinvertebrates should thus take place in the river channel, at sites LT-B-E and

LT-1 to 3. After three years collection of data, monitoring frequency and site number should be re-

assessed.

The standard SASS5 protocol should be followed.

Monitoring personnel: technicians trained in SASS5 bioassessment protocols and macroinvertebrate

identification

Monitoring frequency: ideally quarterly;

Sites: Sites LT-B-E and LT-1 to 3. After three years collection of data, monitoring frequency and site

number should be re-assessed.

8.2.4.3 Invertebrate Habitat Assessment System (IHAS)

The Invertebrate Habitat Assessment System (IHAS) should be applied at the same sites and frequencies

as SASS5 bioassessments. IHAS attempts to account for the variability in the amount and quality of

habitats or biotopes available for habitation by aquatic biota (Dallas 2000). It is related to SASS5 in that

the IHAS scores may be used to adjust the SASS5 scores. This habitat scoring system is based on 100

points and is split into two sections: the habitat sampled and the stream characteristics. The sampling

section is further broken down into three sub-sections: stones-in-current, vegetation and other habitat

or general.

Monitoring personnel: technicians trained in IHAS assessment protocols

Monitoring frequency: ideally quarterly;

Sites: Sites LT-B-E and LT-1 to 3. After three years collection of data, monitoring frequency and site

number should be re-assessed.

8.2.5 Monitoring of flow regime

Monitoring of water flows at the existing DWA weir at Herbertsdale (J4H004) should continue.

Monitoring personnel: DWA personnel



8.2 Monitoring sites

The recommended monitoring sites are as sampled in the Baseline Assessment, and shown in Figure 8.1.

Figure 1 Locations and coding of sites recommended for monitoring, as described in the Langtou

Baseline Assessment of Day (2012).



9 REFERENCES

Dallas H (2000) Ecological Reference Condition Project: Field-Manual. Volume 1: General Information,

Catchment Condition, Invertebrates and Water Chemistry. Report to DWAF, Pretoria.

Day, Liz (2011) Development of an environmental management plan for the Langtou River at

Herbertsdale, Southern Cape – Draft baseline ecological report. Unpubl manuscript prepared for Agri

Wes-Cape with the support oftheTable Mountain Fund, Freshwater Consulting Group, Zeekoe Vlei.

De Villiers C and Bothma J (2010) Fase I van die Langtourivierloodsprojek: Agtergrond, ondersoek,

bevindings en aanbevelings ten opsigte van Fase II. Unpubl. report prepared for the CEO: Agri Wes-Cape,

Paarl.

Holmes PM, Esler KJ, Richardson DM and Witowski ETF (2008) Guidelines for improved management of

riparian zones invaded by alien plants in South Africa. South African Journal of Botany 74, pp 538-552.

draft_langtou emp_170912

Documents

langtou river

management philosophy

langtou catchment

freshwater consulting

river flows

herbertsdale area

southern cape draft

agricultural area