Peak water losses due to evaporation occur between April and June and can be figured as 500 mm/month which is 17 mm/day.
Water losses due to evaporation and seepage should be replaced weekly. According to the operation schedule of ponds, one nursery and one rearing pond are to be filled each week. Thus the water demand for one week in summer is computed as follows:
Filling of ponds: | |
1 000 m3 + 6 000 m3 | = 7 000 m3 |
Losses: | |
17 mm + 20 mm/× 7 days × 5.18 ha | = 13 416 m3 |
Weekly water demand | = 20 417 m3 |
The pumps operate for 6 days and 16 hours per day.
The required pumping capacity is
= 212.7 m3/h = 59 l/s
The recommended pumping capacity:
| 2 units | 30 l/s/unit | Total: | 60 l/s |
| 1.07 cusec/unit/2.14 cusec | |||
