*WRDTC University of Roorkee, Roorkee, India
**N Govi. of Sudan Formerly Graduate Trainee Officer at WRDTC University of Roorkee, Roorkee, India
Large - scale development of ground water calls for optimum design of wells which would deliver water at the least unit cost. Ground water from subsurface reservoir could be lifted by constructing shallow and deep tuhewells. Deep tubewells could be direct irrigation or augmentation wells (wells constructed for augmenting supplies of existing canals).
Designs of deep wells with different capacities ranging between 30 Ips and 200 Ips and with various v.f/ues of diameter, depth and entrance velocity are prepared. Cost analysis of these designs has been carried out to compute capital and operational costs and determine unit cost of the pumped water. Out of the various designs, optimum design for minimum unit cost of pumped water can be selected.
Effect of the aquifer parameters on the unit cost of pumped water has been <letermined. The above computations have been carried out considering the cost of wells and pipes along wth cost of the distribution system and without cost of the distribution system.
Optimum capacity of The deep wells has been found to be in the range of 80 Ips to 100 Ips. Optimum diameter and well depth have been determined for various well capacitie….
The optimum entrance velocity for deep wells has found to be Jess than 0.02 m/s. The unit cost of pumped water decreases with the increase in the values of transmissibility and stor~ltivity of the aquifer. The unit cost of pumped water decreases with the increase in the annual operational hours.
