draft-report - vro | agriculture...

Department of Primary Industries

Forestry Investigation Sites-

June 2009

DRAFT-REPORT

Murray Irrigation Limited


-Weirs Design

Murray Irrigation Limited


THIESS SERVICES, Hydrographic Services - Contact Persons:

Nurullah Ozbey

Manager Hydrology

Thiess Services

ABN: 69 010 725 247

7 Symes Road

PO Box 96

WOORI YALLOCK 3139

Ph: 03 5949 9421

Fax: 03 5961 5741

Mobile: 0427 529 056

Email: [email protected]

The information contained in this document is solely for the use of the client for the purpose for which it has been prepared. Thiess Services and employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise.


Document History and Status

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Draft

Report N. Ozbey M Briggs Draft Report

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Last saved 9/06/2009 9:16:00 AM

File name Rpt0217.doc

Author Nurullah Ozbey

Project manager Nurullah Ozbey

Name of organisation Department Of Primary Industries DPI

Name of project DPI Forestry Investigation Sites

Name of document DPI Forestry Investigation Sites

Document version Draft Report

Project number


Thiess Services Pty Ltd Hydrographic Services Rpt0215.doc

TABLE OF CONTENTS

1.0 SEDIMENT CONTROL MEASURES .............................................................................. 1

2.0 FORESTRY INVESTIGATION SITES’ DRAWINGS............................................................ 3

2.1 SITE: MIRRANATWA - INVESTIGATION CATCHMENT ............................................. 3

2.2 SITE: MIRRANATWA - CONTROL CATCHMENT ...................................................... 8

2.3 SITE: GATUM - INVESTIGATION CATCHMENT ..................................................... 10

2.4 SITE: GATUM - CONTROL CATCHMENT .............................................................. 11

2.5 SITE: NEST - CONTROL CATCHMENT I ................................................................ 12

2.6 SITE: NEST - CONTROL CATCHMENT II ............................................................... 15

2.7 SITE: NEST - INVESTIGATION CATCHMENT ......................................................... 18


Thiess Services Pty Ltd 1 Hydrographic Services Rpt0217.doc

1.0 SEDIMENT CONTROL MEASURES

The measures to protect the bed and banks of the waterway and sediment control

Prepare for work

All downstream neighbours and river users, such as water authorities, shall be notified of the

works.

Everyone involved in the works shall attend a site briefing before starting work.

Minimise sediment disturbance and control erosion

The works shall be scheduled appropriately which shall be timed to coincide with periods of low

flow and completed quickly, and works shall be stopped if conditions are not suitable, such as

during and after heavy rain.

Damage to the ground cover shall be minimised and confined to the works site. Blading and

grubbing of the banks and the area adjacent to the works site shall be avoided.

Any access tracks shall be minimised. Vegetation on unstable and erodible banks shall be

cleared by hand if required If possible; trees vegetation shall be felled away from the waterway.

The type and size of any heavy machinery and attachments shall be appropriate for the site and

the works being done.

All machinery shall be kept out of the waterway on dry and stable areas within the works site.

Existing crossings shall be used to move equipment across the waterway. If there is no crossing

and the stream must be crossed, any disturbance shall be minimised.

If crossing once, the machinery shall be carefully ‘walked’ across the stream. If crossing many

times, a temporary crossing shall be made by laying a pad of clean rock at a shallow point of the

waterway. The rock shall be removed when works have finished.

When excavating the channel where it is required, the flow shall be diverted and the works site

isolated. The stream shall be diverted by constructing a cofferdam using sandbags, clean rock,

steel sheeting or other non-erodible material.

Boulders, rock, shingle, gravels, soil and vegetation from the stream bed and banks shall not be

used or removed without consultation.

Excavated material shall be placed well away from the waterway to minimise erosion back into

the stream. Fill shall not be pushed into the waterway or stored in flood-prone areas.

Avoid contaminant spills



All workers have been trained and equipped to contain equipment spills and leaks.

If a spill occurs, immediate steps shall be taken to stop it polluting the water, including the

ground water. The spill shall be reported to the appropriate authorities as soon as possible.

Petroleum products and other hazardous substances shall be kept out of the waterway.

Refuelling, top-ups and oil checks shall be done well away from the waterway. Fuel and

servicing and refuelling equipment shall be stored so the fluids cannot enter the waterway.

Keep machinery off wet and unstable areas.

Dirt and mud shall be removed from all equipment before entering the works site and

waterway to avoid transferring weeds and disease. Wash-down water is not to enter the

stream.

Fresh concrete shall be kept out of the waterway.

Paints shall not be allowed to enter the waterway when constructing, repairing and maintaining

in-stream structures.

When using wood treated with preservatives, the chemicals shall be given enough time to fix

before immersing the wood in the water.

Stabilise and rehabilitate banks

The site shall be rehabilitated when the works have finished. Native vegetation shall be

established on all exposed soil surfaces,

Further measures to be taken to have maximum benefit from the study with as little impact

as on the environment

Weir will be designed as low as possible to reduce the impact of water speed on downstream

reach and the size of pool formed at upstream while it still provides free-fall flowing condition

hence the accuracy of the data shall not be compromised due to backwater effect from

downstream reach,

Concrete wing walls shall be installed around the weir plate to provide stability for whole

structure and to prevent leakage hence low flow can be captured accurately without any

leakage’s impact on data,

Marine Ply shall be wrapped with plastic lining and sealed with concrete in the ground to

prevent leakage under the weir. Once the study is completed, the weirs made from Marine Ply

can be removed easily to assist the creek to return in its natural conditions.

Rock chute downstream and rock beaching on the banks upstream and downstream of weirs

shall be installed to dissipate water speed to prevent erosion along the reach and provide

stability for the structure.



2.0 FORESTRY INVESTIGATION SITES’ DRAWINGS

2.1 SITE: MIRRANATWA - INVESTIGATION CATCHMENT

The creek bed erosion was observed at downstream of proposed weir location during the

inspection, signifying unstable bed formation and may cause further instability for the weir. In

order to prevent leakage around or under the weir, and to add stability, the weir shall be

supported by wing-walls. Rock beaching is to be placed against the banks of the creek as

illustrated in Figure 3 to prevent erosion and to provide further stability for the structure.

Figure 1- Location of proposed weir



Figure 2 - Proposed Weir Layout



Figure 3 - Plan View

Section A

Knife edge is stainless steel and the weir itself is made from Marine Ply.

0

0.2

0.4

0.6

0.8

1

1.2

7 7.5 8 8.5 9 9.5

Weir Design for Mirranatwa Investigation CatchmentWeir Plate: 53.8° 12.5 Litres/sec at 200 mm height,

100-150 mm

600 mm

Wingwall - Concrete Wingwall - Concrete

Galvanized pipes for support

Natural surface

200 mm

203 mm

200 mm

Weir Marine Ply

Concrete base to stop leakage

800 mm

2.9 m

8.6 m

5.6 m

3.2 m 4.3 m Right Bank

Creek

A

Concrete wing walls (10 cm wide) to harvest water from flat

surface



Figure 4 - Front View - looking upstream from downstream

Right Bank

Figure 5 - Sample for a weir to be built

0

0.2

0.4

0.6

0.8

1

1.2

0 2 4 6 8 10

3.2 m2.9 m4.3 m

Natural Surface

ConcreteConcrete

200 mm Concrete

Marine Ply

L/BR/B



Figure 6- Weir plate dimension-Stainless Steel

Details of crest and sides of V notch for all sites

Downstream side of weir

plate

203 mm

203 mm 100 mm



2.2 SITE: MIRRANATWA - CONTROL CATCHMENT

Figure 7- Location of the proposed weir

Figure 8 Front View - looking upstream from downstream

0.8

1

1.2

1.4

1.6

1.8

2

21 21.5 22 22.5 23 23.5 24 24.5 25

Weir Design for Mirranatwa Control Catchment

Weir Plate: 90°, 200 mm high 400 mm wide

10 -15cm

Wingwall - Concrete Wingwall - Concrete

Galvanized pipes for support

Natural surface

200 mm

400 mm

2800 m

600 mm 600 mm

200 mm

Weir: made from Marine Ply

1000 mm

700 mm



Figure 9 - Weir plate dimension-Stainless Steel

Rock beaching is to be placed against the banks of the creek as illustrated below to prevent

erosion and to provide stability for the structure. Concrete wing walls will be 10 cm wide.

Figure 10 – Rock beaching around the structure

400 mm

200 mm 100 mm



2.3 SITE: GATUM - INVESTIGATION CATCHMENT

Existing broad crested weir U/S of road is to be rated. No construction for a weir is required.

Figure 11 - Broad Crested Weir at U/S of Road

Tasks

1) The crest of broad crested weir is to be paved (edges are not to be rounded) to improve

the accuracy of rating table, –THIESS Hamilton

2) The pool behind the weir is to be cleaned, –THIESS Hamilton

3) The right bank on the edge of concrete is to be blocked for accuracy, -THIESS Hamilton

4) The rating table and accuracy statement will be developed after the gauge board is installed and

the survey is conducted to tide the crest level to the gauge datum.



2.4 SITE: GATUM - CONTROL CATCHMENT

The existing V notch weir plate U/S was corroded. The weir plate is to be built and installed at

existing infrastructure. Inlet pipe of stilling well also is to be extended.

Figure 12 - Existing Weir



2.5 SITE: NEST - CONTROL CATCHMENT I

Figure 13 – Location of Proposed Weir



Figure 14 - Proposed Weir

Section A

0.5

0.7

0.9

1.1

1.3

1.5

1.7

1.9

2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7

Weir Design for Site: Nest - Control Catchment -1

950 mm

1200 m

Weir Plate: 90° - 500 mm wide 250 mm high

3200 m

Wingwall - Concrete

Galvanized pipe supports

Natural surface


750 mm100-150 mm

100 mm

500 mm

250 mm

A





Figure 15 Rock beaching around the structure



2.6 SITE: NEST - CONTROL CATCHMENT II

Figure 16 –Location of proposed weir




Section A

1

1.2

1.4

1.6

1.8

2

2.2

2.4

1 2 3 4 5 6 7

Weir Design for Site: Nest - Control Catchment 2

1000 mm

2500 m


5000 m

Wingwall - Concrete


Natural surface


700 mm

200 mm

100-150 mm

100 mm

500 mm

250 mm

A



2.7 SITE: NEST - INVESTIGATION CATCHMENT

Figure 19 – Location of proposed weir




Section A

0.7

0.9

1.1

1.3

1.5

1.7

1.9

7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12

Weir Design for Site: Nest- Investigation Catchment

650 mm

4750 m


2500 m

Wingwall - Concrete


Natural surface


1000 mm

200 mm

100-150 mm

100 mm

A

500 mm

250 mm

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