Aquaculture Engineering (2+1)

Detailed survey - Main factors

Unit 2- Fish Farm

Detailed survey
Main factors - Site condition

The proposed site for pond construction should be essentially having sufficient area to accommodate all the desired number of ponds. The site is considered to be ideal for pond construction if the land surface is flat or has uniform gentle slope in one direction. It gives facilities for quicker filling and emptying of the pond water. From the economic point of view a pond should be located where the largest storage volume can be obtained with the least amount of earth fill. This condition generally will occur at a site where the valley is narrow, side slopes are relatively steep and slope of the valley floor will permit a large deep basin.

Avoid a site in a valley, relatively open and wide at down stream end. If so it is necessary to build long dam. It increases the cost of construction. Site should be good soil, which will hold the water well. The site should have the facility to adequate drainage arrangement. It is necessary to avoid forest area or the site with full of large number of trees. Other wise which may difficulty to remove and it leads to increase the cost of construction and also create problems during operation and maintenance. Dampy areas are also not suitable for pond construction because pond drainage is always difficult and much expensive. The optimum slope is between 0.5 to 1%. The ground slope should not be more than 2% as it needs construction of high and costly embankments. Shape of the site should be regular, irregular and oblong shape results in difficulty for planning, designing, construction, operation and maintenance of ponds. Sites with excessive undulating topography should be avoided as a lot of excavation and embankment would be needed during the construction, which will increase the cost of construction. The area should be sufficiently extensive to allow future expansion.