Design of water supply facilities for a tidal fish farm in the Niger Delta, Nigeria

Abstract

Studies to redress the water supply problem by designing water supply facilities (inundation canal with sluice gate, a reservoir, and a pumping station) for African Regional Aquaculture Centre (ARAC) fish farm located in Aluu, Rivers State of Nigeria were carried out for twenty-four months. The topographic survey of the area indicated gentle sloping woodland, with the highest and lowest elevations of 11.00 and 1.00 m respectively above ordinance datum. The longitudinal section of the proposed canal indicated relatively flat tidally fed wetland, with the highest elevation of 1.70 m and lowest elevation of 0.47 m above ordinance datum. The mean peak heights of water in the study canal during spring tides ranged from 0.95 to 1.45 m. On the other hand, the mean peak height of water during neap tides ranged from 0.38 to 0.86 m. The floodtide and ebb tide velocities of canal water flow ranged from 0.40 to 0.75 m/s and 0.72 to 0.92 m/s respectively. Soil particles size analysis showed predominantly loamy clay soils. Mean surface water temperature readings ranged from 23.50 to 29.00 O C. Dissolved oxygen (DO) content ranged from 5.80 to 7.40 mg/L. The corresponding DO deficits ranged from 2.35 to 0.20 mg/L, indicating a moderate level of pollution. pH values of canal water flow ranged from 5.80 to 6.97 units, which is considered slightly acidic. The transparency of the river ranged from 95.00 to 199.00 cm, while total hardness values ranged from 12.90 to 50.20mg CaCO 3 /l. The water quality characteristics showed seasonal variations, attributed largely to the dilution effect of the rain. The baseline data were considered adequate for the design of water supply facilities for the farm. Keywords: Tidal water levels, fish farm, wetland, water supply, Niger Delta International Journal of Natural and Applied Sciences , 7(1): 94 - 103, 2011