Guidelines on fish pond construction

Kenya has an estimated 80,000 ponds throughout the country with production of over 22,000 metric tonnes. Fish farming in ponds are now a major source of income for thousands of Kenyans contributing 2% of the national fish production

Apart from being a major source of protein, fish farming is now a business of choice for many after an initial lacklustre performance that discouraged many people from venturing into the trade. The increase has been brought about by the substantial income earned by farmers and the opportunities for companies producing accessories of fishpond construction like dam liners to expand their business.

Why Fish Farming in Kenya?

There are many advantages of starting commercial fish farming business in Kenya. Here we are describing the main advantages of fish farming business.

• According to the demand, commercial fish farming business allows for large supplies of fish. Catching fish from the wild can’t always fulfill the consumer’s demand. In such cases commercial fish farming can meet up this demand.
• Fish can be raised in tanks until they are ready for marketing, and they don’t require the extensive capture of wild fish. Thus commercial fish farming helps to preserve natural ecosystems.
• Compared to the wild brethren, some farm raised fish species are more nutritious. Fish are usually fed a wide variety of protein and nutrient enriched foods or pellets on commercial fish farms. So farm fish become more healthier than the wild fish.
• Various types of fish species are available throughout the world. So you can choose your desired species for your fish farming business.
• Fish are very popular as food around the world. So there is an established fish market, and you don’t have to worry about marketing your products.
• You can start fish farming business in both large or small scale production purpose.

• If you don’t have enough capital for starting this business, then you can apply for bank loans. Many banks will allow loans for starting this business commercially.
• Fish farming business is a great source of employment. More than 1 billion people around the world depend on fish as their primary protein source. And most of this people are directly or indirectly involved with fish products or fish farming business. As a result, fish farming creates a great income and employment source for the people. Global fish exportation business is now earning more money every year, than any other food commodity.
• Even you can meet up your daily family nutritional demands through small scale fish farming in tanks or ponds.

Fish Pond Construction in Kenya

When building ponds for an aquaculture farm, there are a number of processes and guidelines that you should follow.

Designing containment structures

Consider the following factors when designing aquaculture ponds:

• Farm layout – aim for the lowest possible risk to surrounding land, accounting for run-off, flooding, noise and odour.
• Containment structures – before building your containment structure you should assess the design of foundations, embankments, freeboards, inlet/outlet works.
• Intake and discharge points – by using concrete blocks, rock armouring and other design solutions you can minimise erosion and leaks around intake and discharge points.
• Buffer zones – mound formations provide separation between containment structures and environmentally sensitive areas and beneficial land uses.
• Engineering plans and drawings – seek the advice of a qualified personnel when designing aquaculture facilities. Up-front costs for their expertise can be offset by savings on construction and operating costs.

Building containment structures

Consider these construction steps for aquaculture ponds:

• Notification – notify administration authorities such as county governments before any construction begins.
• Site preparation – before you begin construction, clear all trees and woody materials; you may require a permit to remove native plants.
• Material suitability – make sure you line the structure with well graded, impervious material.
• Placement of material – when deciding where to place materials you should consider earth material lining, embankments, erosion control and pipes, culverts and weirs.
• Correct moisture content – material used for lining should be treated to meet moisture content standards needed for compaction and low permeability.
• Compaction – each layer of material should be compacted to a density greater than 95% of the standard compaction density.
• Documents and records – a certified personnel should prepare a post-construction report confirming that the structure has been built to the certified plans and drawings. Any reasons for variations to the plans should be documented. Keep records of all excavation works and foundation levels and document any testing of earthworks undertaken during construction.

Monitoring pond structures

Monitor your pond structures after they have been built to make sure they are working properly:

• Purpose – assess the impact of containment structures on the environment by checking for potential leakages, embankment instability and contamination of pond water quality.
• Visual inspections – regular visual inspections should be carried out to identify any potential problems.
• Groundwater monitoring – helps identify significant problems with containment structures.

Maintenance programs for containment structures

• Routine maintenance – develop a routine maintenance program for your containment structures, which includes repair of erosion, pond floors, and removal of woody vegetation.

Fixing structural issues with aquaculture ponds

• Structural repairs – fixing aquaculture ponds can be costly. If structural issues do occur, you should consult a qualified engineer.

Stocking of Fish Pond

Stocking normally takes place after pond preparation and liming. Stocking is a means of introducing an adequate number of selected fish species of proper size into the ponds. It involves the transportation of live fish.

Factors to consider when constructing a pond

• Before beginning the construction of a new fishpond, carefully consider the design. A properly designed and constructed pond will be easily managed and will last longer, saving extra work
• Also consider the water sources used for fishpond
• The size of a prospective fish pond should be based on the purpose of the pond
• The pond bottom must have sufficient slope for good drainage. In general, slopes with a drop of 2 cm for every 10 metres along the pond bottom are appropriate
• Pond drains are normally located at the deep end of the pond with the bottom