Design & Engineering
Walwhan dam is one of the dams in the chain of reservoirs constructed to supply water to Khopoli Hydro Power Station of Tata Power Company Limited. Water from Walwhan reservoir is carried through a 7 km long open channel up to Khandala forebay wherefrom it is led to Khopoli Power house through a system of penstocks. The dam, 1.3 km long constructed between year 1911 to 1916 is a gravity dam constructed in rubble masonry has a maximum height of around 26 m with a storage capacity of 72.55 Mm3.
When constructed, the dam was not designed for earthquake forces and uplift pressures. In view of the recent seismic activity in this region, the dam has been strengthened to cater to earthquake forces as well as uplift pressures. Strengthening has been carried out by construction of buttresses in colgrout masonry at the downstream face of this dam. The buttresses 59 in number are 9 m thick and 14 m wide. The buttresses have been designed for raised FRL of the dam by another 0.6 m.
The spillway capacity of the dam was designed on the basis of the empirical flood formulae. As required by current design standards the spillway capacity has been now been designed to cater to probable maximum flood (PMF) by modifying existing spillway. The proposed new spillway arrangement is 72 m long and provided with 13 automatic tilting gates each of size 5 m x 1.4 m each.
TCE Scope of Work