'Balanced' development refers to development that also brings healthy growth to the local community either in terms of economy and living comfort.
However development should not be detrimental or hazardous to the environment.
Hence before development is carried out, authorities should identify the 'green lung' zone for the benefit of the environment.
The size of the green lung should reciprocate the size or area of development, as determined according to the development-population ratio approved by the authorities.
According to a study conducted by the Selangor Drainage and Irrigation Department (JPS), the soil's rate of water absorption is getting lower due to the gradual diminishing zone and size of green lungs.
"A mature tree can absorb and store 70-80 gallons or more than 300 litres of water from the soil at any one time. If a tree was felled, the excess water would flow looking for holes in the ground. Other factors prevent it from flowing into drains (and cause floods)", said Ishak Samsudin who is an engineer with the Selangor JPS.
He said water, without proper catchment or retention area would flow into drains and finally into rivers.
RIVER BED
Ishak said the sedimentation on the riverbed and erosion of its banks with the soil going into the river would make the river shallower, hence reducing its capacity to hold water.
As a result, the river would overflow its banks and in cases of heavy downpour, a flash flood would happen.
This is the reason why priority should be given to conserving rivers and green lungs.
RETENTION PONDS
This excess water should be channelled and conserved well.
"Without trees, there will be only smooth and unhindered flow of water. The abscence of flat and open terrain would offer no resistance to the water from flowing into drains. Development upstream would cause sedimentation to occur downstream", Ishak told Bernama.
According to the manual issued by Saliran Mesra Alam, a construction firm that undertakes development projects, a detailed outlook should be taken on this 'excess water'.
Two issues have to be taken into account.
The 'on site detention' (OSD) which are catchment ponds and 'control on discharge' (COD) regulation of water production.
The manual calls for project operators to obtain the nod from authorities in their respective area of operations.
JPS is the authority that issued the appraisal letter for the construction firm to submit to the local authorities before commencement of the project.
After construction of the water retention pond is completed, the pond is to be placed under the charge of the local authority.
RIVER FLOW
Dr Kalithasan Kailasam, the river care coordinator at Global Environment Centre (GEC) said the overflowing water due to floods and downpours should be retained for at least 48 hours before being discharged into rivers.
"This is to enable the water to leave its toxic and metal contents before flowing into rivers. The water should be retained in ponds with earth bottoms instead of having concrete beds.
"The ponds should have 'wetland' or swamp vegetation that helps to improve water quality", said Dr Kalithasan who is an expert in river conservation.
GEC is a non-governmental organisation (NGO) that calls for the existence of lakes and retention ponds in housing and industrial areas to ensure water flowing into rivers is safe for human consumption as well as recreational activities.
FLASH FLOODS
Sungai Damansara in Shah Alam, overflowed its banks and discharged its contents in 2006/2007 into the TTDI Jaya housing estate, causing heavy damage to the residents' properties.
Now there are water retention ponds, built to accommodate water from downpours over this area and its surroundings.
The move is to contain water that cannot flow naturally into the river.
There are several of these ponds in this area now and the incidences of flash floods are rare.
Meanwhile construction firms that are responsible should construct water retention ponds in their respective development areas.
Man-made water retention ponds can accommodate excess rainwater that overflows drains, making rivers not the destination of this (excess) water and avoiding floods.
RECREATIONAL LAKE
For example in Subang Jaya, there is a recreational lake located right in the area where hotels and a hospital are located near SS12.
The eight-hectare lake, known as Taman Tasik Ria, was earmarked for development and the residents were up in arms and protested against this proposal.
The final say was that the lake remains as a recreational lake.
There are three water retention ponds in Subang Jaya dan USJ.
Four are in Sunway which is not far from Subang Jaya. All together there are 38 retention ponds built by the developer in the Subang Jaya Municipal Council (MPSJ) area of jurisdiction.
Only 11 were handed over to the MPSJ for maintenance and the council spends almost RM200,000 a year on this.
TECHNOLOGY
State-of-the-art technology enables monitoring of rivers via the 'Geospatial’ (GIS) method which is accessible through the Internet.
Many government entities related to environmental monitoring are using such technology including the JPS which is utilising it to monitor the depths of rivers as this technology provides data on depths of rivers.
"This sophisticated technology can read the depth of rivers, provides data on sedimentation apart from erosion which are crucial to prevent disasters from happening", said Tahir Shafiq of Canada. Shafiq is a representative of Trimble, a company based in United States.
He was in the federal capital recently to provide briefings on the usa of GIS technology for bodies involved with development in Asia.
"Several ministries in Malaysia have been using this GIS system which is easy to access. This equipment is portable and can easily be used for airborne monitoring and surveillance", said Shafiq.
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