Aquaculture Engineering

Pumps - Computation of water requirement - Problem 1

Unit 12 - Management of ponds

Pumps

Computation of water requirement
Problem

1. Determine the number and capacities of freshwater and sea water pumps required for a shrimp farm having 10 ponds, each with water spread area of 1 ha. Assume the following data.

Average depth of water in the ponds = 1 m
Anticipated maximum water exchange rate in a day - 50%
Sea water salinity - 35 ppt
Required salinity in the pond water - 15 ppt

Available period for pumping freshwater and seawater =12 hrs/day
Also, assume average water area of each pond to be nearly equal to its water spread area i.e., 1 ha. Values of precipitation and losses due to seepage and evaporation are negligible.
Volume of water in each pond =Average area of pond x Average depth of water in the pond = 10,000x1 = 10,000 m³
Total volume of water (V) = 10 x10,000 = 1,00,000m³ (10 No. of ponds)