As part of the key initiatives under the Water Stewardship Agenda, Spark Foundation with Global Environment Centre (GEC) in partnership with Selangor State Forestry Department (SSFD) has been conducted an assessment since 2018 to identify the suitable site to construct the clay dyke as water management and fire prevention measures in highly fire risk area at Raja Musa Forest Reserve (RMFR). It’s a pilot project as it is first time in Malaysia to look into correlation between clay dyke and water storage for water supply.
With support of the SPARK Foundation and approval from Selangor State Government and Selangor State Forestry Department, the clay dyke construction started from 1st October 2019 at Location: FC 102, RMFR (Coordinate : 3.45224, 101.43637) @ Parit 1 (Local Name). The clay dyke is an innovative method, where peat is dug and replaced with clay to retain water and reduce surface and subsurface water seepage expect through installed HDPE poly pipe outlet at 5 spots. Each outlet has two HDPE pipes for channeling excess water to the ex-mining pond area to increase water supply and the height of the water discharge level is adjustable. As per main objective of Water Stewardship Agenda, clay dyke constructed initiated to serve 2 main components as below:
i) To prevent peatland fire events through water retention
ii) To support alternative water supply to Sg Selangor water catchment especially during dry weather
iii) Retain water during the wet season for slow release later, especially during times of dry weather
As mentioned above, peatland fire prevention will also help long term storage as frequent peatland fires destroy the surface peat layer and reduce the storage potential of the peatland.The clay dyke built as a vertical wall of clay 4-5m tall constructed mainly below the peat surface over a distance of 305m in the forest edges at RMFR to maintain high water levels in the forest edges, and reduce rapid loss of stored water in the wet seasons. In addition the dyke raises water levels and reduces the vulnerability to forest fire as these areas previously have been over-drained and fire prone. Main steps involved are:
Excavation and digging of canal for peat removal
Transporting, filling and compacting the clay
Installation of “Stick Gauge” as water level indicator
Installation of HDPE poly pipe as an outlet within the clay dyke
Clay dyke stops rapid lateral outflow or seepage of water into the adjacent clay mine and raised the water level up to optimum in the remaining peatland. Potential benefits from the clay dyke are :
1. Water storage
The MBI ponds nearby FC102 is part of Hybrid Off-River Augmentation System (HORAS 3000). HORAS 3000 utilizes pumping of water from MBI ponds to Sg Air Hitam, then Sg Selangor that used as water intake especially during dry weather. Clay dyke ensure water retention and provide slow release into ponds during dry weather.
2. Reduce fire occurrence and saving of water from reduced fire-fighting operations
Firefighting uses pump with a capacity of 1m3/second to pump water from the mining lake to the fire consumed area. Assuming that the pump is operated for 6 hours per day during the 20 days of fire control a total of 400,000 m3 of water is used per year for fire-fighting operations. Clay dyke able to significantly reduce the risk of fire. Even with 50% reduction there would be a saving of approximately 200,000m3 of water per year.
3. Natural regeneration of vegetation
Earlier clay dyke project by SSFD led to good natural regeneration of vegetation due to wetter condition. Similar result anticipated through W.A.T.E.R Project clay dyke initiative.