Stormwater Management

Stormwater ManagementGroup members: Chuang Jing 0322934 Gan Xiao Ying 0322998Koh Wen Qi 0323355Yeo Dor Een 0316224 Chen Shin Yee 0322650Siong Jia Yii 0318239

Stormwater is rainwater and melted snow that runs off streets, lawns and other sites. When stormwater is absorbed into the ground, it is filtered and ultimately replenishes aquifers or flows into streams and rivers.

EFFECTS of Poor Stormwater ManagementDownstream floodingStream bank erosionIncreased turbidity from erosionHabitat destructionCombined sewer overflowsInfrastructure damageContaminated streams, rivers, and coastal water

Jia Yii (JY) - Stormwater is actually concern for two main issues:

Related to the volume and timing of runoff water (flood control and water supplies) Related to potential contaminants that the water is carrying, i.e. water pollution.

ADVANTAGES & DISADVANTAGES

AdvantagesProvides proper drainage of surface run-off and avoids damages on infrastructure such as private properties and streets.Provides possibility to recharge groundwater and re-use precipitation water and surface run-off as irrigation or household water.Minimizing health risks.

Provides effective stormwater flood control. Can be integrated into the urban landscape and provide green and recreational areas.Revenue generated by a stormwater utility can be used as a new, dedicated source of funds to supplement or replace the community's current stormwater management funding, enabling tax-based funding to be used for other community needs.

DisadvantagesExpert planning, implementation, operation and maintenance required for a stormwater management. It depends on the technique, a lot of operation and labour required. There is risk of clogging infiltration system caused by high sedimentation rates.Temporary covering methods, such as plastic sheeting, can become torn or ripped, exposing the contaminant to precipitation and/or storm water runoff.

Examples of Sustainable Storm Water ManagementIncorporates both the natural environment and engineered systems Promote sustainable stormwater management practice toreduce runoff, improve water quality and encourage infiltration.Green roofs / Rain Gardens / Porous PavementGreen infrastructure At the scale of a neighborhood or site,greeninfrastructurerefers to storm water management systems that mimic nature by soaking up and storing water.

Rain GardensConstructed depressionManage and treat small volumes of storm water by filtering runoff through soil and vegetationHoldsthewater for a short period of time and allows it to naturally infiltrate into the ground

Bioretention AreasConstructed depressionLarger than rain gardens and designed with an underdrain to connect to the storm drain system.

VegetatedSwalesA natural drainage paths or vegetated channels transport water instead of underground storm sewers or concrete open channels to convey stormwaterrunoff.

GreenRoofsA system of roofingthat uses plant life for roof covering instead of traditional covering materialslayers of soil and vegetation installed on rooftops that capture runoffi. provide an excellent insulation to the buildingii. Reducing energy consumption significantlyiii. Act as a natural filter for rainwateriv. Allows evaporation to reduce the volume and discharge rate of storm water

PorousPavementApermeablepavement surface with a stone reservoir underneathThe pavements allow storm water to infiltrate directly into the soilOften appears the same as traditional asphalt or concrete but is manufactured with incorporates void spaces that allow for infiltration.

Porous pavement

StreamBuffer RestorationNative trees and bushes plantedalong the stream or ditchStrips of trees and other vegetation buffer helps improve water quality and maximized stream damage By filtering and slowing polluted runoff

Installation process

INSTALLATION PROCESS OF RAIN GARDENTo lock down location of utilities prior to digging. To lay out shape of rain garden with equipment.Kill or remove existing turf.Compost and sand have to be mixed into stockpile topsoil.Excavate subsoil and use it to create a compacted berm.Work from the side of the rain garden to prevent compaction of soil in the rain garden. Thoroughly mix and add 50% washed sand, 30% compost, 20% topsoil. Make sure the rain garden is level and the proper depth. Put down a 2-3 inch layer of shredded hardwood mulch. Begin planting. By adding flagstone, rocks, or other protective products is one of the ways to protect against erosion where water enters the rain garden.Have a designate and armored outlet for flows from heavy rains that exceed the design capacity.

INSTALLATION PROCESS OF VEGETATED SWALESRough grade the vegetated swale. Construct check dams, if required.Fine grade the vegetated swale. Prior to establishment of vegetation, a swale is specifically vulnerable to scour and erosion and therefore its seed bed must be protected with temporary erosion control.If all tributary areas are enough stabilized, remove temporary erosion and sediment controls.

INSTALLATION PROCESS OF GREEN ROOF Install a monolithic type waterproof membrane such as rubber and plastic on top of the roof decking.Place a 6mm sheet of plastic on the waterproof membrane and the waterproof membrane will serve as a root barrier.Top the first two layers with one or more thin sheets of three-quarter-inch foam insulation suited for contact with damp soil. Set a drainage mat which also called as a dimple mat with capillary spaces on top of the insulation.Frame the sides for the roof with mesh gutter guards, wood or other edging that will permit drainage to hold soil in place. Add soil.Set plants in place.Water to settle soil around plants.

CASE STUDY

SMART TUNNEL

Stormwater Management And Road Tunnel = SMART TunnelA storm drainage and road structure in Kuala Lumpur, Malaysia.The project is implemented through a joint venture pact between MMC Corp Berhad and Gamuda Berhad.The 9.7km (6.0mi) tunnel is the longest stormwater tunnel in South East Asia and second longest in Asia. Construction cost : RM1887 millionTwo major components of this tunnel :stormwater tunnelmotorway tunnel

North endSultan Ismail- Kampung Pandan LinkKuala Lumpur Middle Ring Road 1 (Jalan Tun Razak)Kuala Lumpur-Seremban ExpresswayEast-West Link ExpresswaySouth endSMART Tunnel toll plaza near Sungai Besi AirportObjective Solve the problem of flash floods in the city centre of Kuala Lumpur by divert large volumes of flood water via a holding pond, bypass tunnel and storage reservoir. Reduce traffic congestion at the Southern Gateway The motorway tunnel provide an alternative route for motorists from the Southern Gateway, i.e. KL-Seremban Highway, Federal Highway, Besraya and East-West Link entering and exiting the city centre.

Additional Features of SMART TunnelAlam Flora Road SweeperSCADA Monitoring & SurveillanceRadio Re-Broadcasting ServicesAutomated Flood Control Gates First Responder Vehicle (FRV)Ventilation/Escape ShaftsMedical Response Vehicle (MRV)Cross PassageAir Quality Monitoring Equipment (AQME)Other Emergency Equipment

Alam Flora Road Sweeper Has a water tank and would be able to carry around 1000 litres per sessionHandling operations for the cleanliness in SMART Tunnel during minimum disruption to traffic flow, means at nightThe dimension of the main broom is 1500mm in length and 400mm in diameter while the gutter broom measures around 500mm in diameterThe Road Sweeper has a hopper capacity of +/- 5.0cu.m and a vacuum type true flow air system using a fan blower output of +/- 450m3 per minute.

SCADA Monitoring & SurveillanceState-of-the-art 24-hour at its highwayBARCO Wall is able to show 70 CCTV screen at one timeAutomatic Detection Systems use video images and laser beams processing to detect unusual eventsMore than 212 units of Closed Circuit Television in the SMART tunnel

Radio Re-Broadcasting ServicesAble to receive the radio channel, phone call or other communication reception without any interference because stations can link in radio networks to broadcast common programming (either in syndication or simulcast or both), local wire networks, internet and satellite

Automated Flood Control Gates 3 Automated Flood Control Gate at both end of motorway2 Automated Flood Control Gate at both end junction boxesThe water tight gates are operated using a hydraulic systemThese gates are installed on either ends of the motorway or similar single flood control steel gates are installed at both entrances and exits of the motorway tunnel

First Responder Vehicle (FRV)Custom-Built Fire Engines for SMART HighwayThe FRVs were customized to meet the sophisticated design of the SMART Tunnel such as height limitations, tunnel manoeuvrability, special equipment housingIs powered by an engine that produces minimal carbon emission in order to ensure safety in the tunnel is maintained throughout an emergency operationUnder the special requirements of the National Fire Protection Agency

Ventilation/Escape ShaftsThese powerful air ventilators will constantly renew the air and maintain the air quality within the motorwayThe system consists of a series of shafts each containing an exhaust and fresh air injector too protect the ventilation system during the floodingThe features also allows for smoke control in the event of a fire.

Medical Response Vehicle (MRV)MRV is a custom-built Ambulance which is capable in giving the first responder services or further emergency treatment for SMART HighwayThe advantages of the MRV is it can transport the Emergency Medical Specialist or the medical team to wet, skidded and limited eye vision and also off road situation.

Cross PassageCross Passage between decks at 250m intervals: the passage acts as emergency exits.

Air Quality Monitoring Equipment (AQME)There are 38 sets of AQME monitoring Carbon Monoxide (CO), Nitrogen Monoxide (NO) and particulateThey are cited in the upper and lower decksThe ventilation will provide for the supply and extract of air for both the upper and lower road decks It will be operated automatically based on the air quality monitoring system outputs.

Other Emergency EquipmentEquipped with fire fighting equipment, telephone and surveillance at 1km interval. Hydrant & Fire Extinguishers located every 90m.

Mode 1 When weather is fair with little or no rain and traffic is allowed in the tunnel.Mode 2Activated when moderate rainfalls and the flow rate recorded at the confluence of upper Klang river/Ampang river (L4 flow station) is 70-150m3/s. Only 50m3/s is allowed to flow downstream.Excess flood water will be diverted to SMART storages and only the lower drains of tunnel will be used to convey flood flow to the Desa attenuation pond.Road tunnel will still opened to traffic.

Mode 3Activated when major storm event occurs and flood model forecasts a flow rate of 150m3/s.Traffic will be evacuated from the road tunnel. This is normally takes about an hour. Only 10m3/s is allowed to flow downstream.Road tunnel will be re-opened to traffic within 2-8 hours after closure.

Mode 4Activated if heavy storm prolongs, usually will be confirmed 1-2 hours after Mode 3 is declared.Road tunnel will be used for passage of flood after traffic evacuation completed. Only 10m3/s is allowed to flow downstream.Road tunnel will be re-opened within 4 days of closure.

PROBLEMS

LimitationSMART tunnel can only mitigate flooding in the city center where it covers.SMART tunnel cannot work by itself. It need two components to complement each other to curb floods, example the ponds.According to New Sunday Times, the SMART tunnel is designed to handle only 45 percent of floodwaters coming from the rivers.

High maintenance feesAccording to Big boy big toy, 2011 , SMART tunnel comes with a hefty maintenance fees which costing RM20 million per year. Such sum of money comes from tax payers.

LOW USAGEPEOPLE ARE SAYING THAT GOVERNMENT REFUSES TO OPERATE THE TUNNEL NOW BECAUSE THE GOVERNMENT WANTS TO COLLECT TOLL THROUGH SMART TRAFFIC OPERATIONS.

Traffic jamWhen SMART tunnel requires times to clean up thus it will be closed to public , this will cause the traffic congestion problems remains unsolved.

Blind cornerThe exit of tunnel is concealed behind the blind corner hence some drivers would possibly stop suddenly in the middle of road because they have no idea which road to exit.More road signs or notifications are required to inform the drivers where to exit.

Road conditionsMany of the road users complained about the bumpy road in the SMART Tunnel as it may become a minor nuisance to all the drivers that would cause minor damage to cars and even result in a car accident.However, according to Mohd Noor Mohd Ali, this special rough road surface is designed with features to reduce speed.

FUTURE IMPROVEMENTS

Low Impact Development(LID) Methods of LIDInfiltration practiceRunoff storage practice

Infiltration practices constructs structures or landscapes to infiltrate runoff water

FUNCTION OF INFILTRATION PRACTICES:REDUCE THE VOLUME OF DISCHARGED STORMWATER AND INFRASTRUCTURE REQUIRED TO BE CONDUCT, CURE OR MANAGE RUNOFFSLIP DEVELOPMENT OR IMPROVEMENT IN WHICH IT BRINGS LESS OR NO HARM TO THE ENVIRONMENT WHICH IN THIS CASEBASICALLY MEANS DEVELOPMENT TO STORMWATER MANAGEMENT WHICH IS GREEN AND ENVIRONMENTAL FRIENDLY

Runoff Storage PracticesExamples: green roof / Eco roofThe roof is planted with plants as storm water management processes instead of using concrete or glassThe plants are able to trap rain water for storage to be reused and at the same time it waters plants

Runoff practices can be implemented in car parks, streets, and pedestrian paths by installing storage tanks below them.It is a direct discharge from the surface to be stored temporarily in underground storage tanks in order to control the flow of storm water drainage.

Positive environmental effects of LID Recharge of groundwaterImprovement of water qualityProtection of downstream resourcesImprovement of habitatImproves aesthetics in streams and riversAbatement of pollutionConservation of water and energyReduced downstream flooding and erosion

THANK YOU!