Realising that there is an urgent need for conservation and protection of Osmansagar and Himayathsagar reservoirs, Hyderabad Metropolitan Water Supply and Sewerage Board (HMWS&SB) of late, have decided to take remedial measures to protect them.
The Osmansagar was built between the year 1912 and 1920 while Himayatsagar was constructed in 1920. The two lakes serve as major sources of drinking water to the citizens of Hyderabad. As of today, the two reservoirs together supplies about 25 to 30 millions of gallon of water per day (MGD) to different parts of the twin cities.
Because of the large scale development close to these lakes, the water quality has been deteriorating as illegal sewage is being let into these lakes as illegal structures have sprung up on a large scale in the vicinity.
The National Environmental Engineering Research Institute (NEERI) a research institute that was created and funded by the Central Government conducted a detailed study on the condition of these two reservoirs few years ago and submitted its report to the HMWS&SB. In their report, they informed that these two lakes were being polluted due to sewage inflows, aquaculture and other illegal activities that were taking place at these lakes.
The HMWS&SB then invited Expression of Interest (EoI) from various firms and agencies for preparation of Detailed Project Report (DPR) under National Lake Conservation Plan (NCLP) for protection and conservation of Osmansagar and Himayathsagar.As many as 17 firms responded to the EoI on preparation of DPR.
HMWS&SB officials told Express that based on the recommendations of NEERI, the selected agencies should carry out studies of existing systems of two reservoir structures, inflow pattern, rainfall and hydrological data. They will also be required to study the existing Operation and Maintenance manual as well as Environment Protection Training and Research Institute [EPTRI] and NEERI reports.
The agencies will also study GIS mapping of full tank level (FTL) contours, water spread area at FTL to demarcate the lake boundaries and fixing of FTL pillars at 100 mts interval in coordination with Revenue department and super imposing the FTL maps in revenue maps including the cost estimate.
They will also be studying the adoption of suitable protective measures such as cahin link mesh fencing, construction of bunds, trenches digging in order to to establish lake boundaries and to prevent encroachments into the FTL areas of the lakes. Study on the entry point of sewage from surrounding villages and their discharge pattern, population studies and projections will also be undertaken, they added.
After undertaking the studies, they will be required to suggest construction of STPs, I&D structures, diversion, locations and availability of land and effluent discharge through neutralisation such as root zone treatment including cost estimates, designs and plans.
Besides this, they will also be studying the identification of non-point sources of pollutants including fertilisers, toxic pesticides and other chemicals from agriculture run off entering the lakes and measures to prevent them.