Hydrographs of bores adjacent to the Little Para River show that it is an important source of recharge to aquifers of the Salisbury area. Recharge takes place via shallow aquifers and then to deeper aquifers through semi-confining beds and possibly through the Para Fault Zone. On the basis of change in storage of the shallow aquifers average annual recharge is estimated to be 2350 megalitres. It has been estimated, on the basis of stream flow measurements in the Little Para River, that a total annual flow below the dam site of 3318 megalitres is required to maintain the current situation. It is considered that evaporation and transpiration accounts for 968 megalitres of the annual flow. Urban and rural run-off entering the Little Para River below the proposed dam is estimated to be 1100 megalitres per year of which 600 megalitres may be conserved by appropriate works. If this were done then the quantity which must be released from the dam could be reduced to 2700 megalitres per year.