Peak water losses due to evaporation occur between May and July and are calculated as being 400 mm/month that is 13 mm/day. Evaporation and seepage losses should be replaced weekly. According to the operation schedule two nursery and two rearing ponds should be prepared for stocking each week. The inflow of rain water is neglected in this calculation.
Filling of ponds: | |
2 × 1 400 m3 + 2 × 6 600 m3 | = 16 000 m3 |
Losses: | |
13 mm/day + 10 mm/day/ × 7 days × 12.0 ha | = 19 320 m3 |
Weekly water demand | = 35 320 m3 |
The pumps operate 6 days per week and 16 hours per day The required pumping capacity is:
 | 367.9 m3/h = 102 l/s |
The recommended pumping capacity:
| 2 units 51 l/s | Total 102 l/s |
| /1.82 cusec/ | /3.64 cusec/ |
