One of the natural disasters that affect catfish production in artificial dams and ponds is flood. Flood occurs when runoff water goes beyond channels and drainages provided for it. It is a situation whereby water bodies (lake, stream, rivers, etc.) go beyond their catchment area causing untold damage to the adjoining environment.
Excess precipitation has been identified as the major cause of flooding, especially in the developed countries of the world where networks of drainages exist and are well kept. At times, there could be nonstop rain for more than 24 hours, causing drainages and water bodies to be overwhelmed and spread to the surrounding environment. In other words, Nigeria as an example of underdeveloped country has experienced a number of floods not as a result of excessive rainfall but due to poor drainage systems and poor maintenance of existing ones. This may at times result in severe loss of properties and livestock (catfishes, cattle, chickens, etc.) worth millions of dollars.
I can remember a couple of years ago before I started this business of catfish farming. I was going on a highway. I saw a number of people gathered immediately after about two hours of heavy downpour, picking catfishes on the shoulders of the road. It later came to my notice that some ponds were flooded in the farms not too far away from the scene of the event. The owner of one of the farms later collapsed and died because he took a loan from a cooperative society to raise his fishes. My personal experience in this regards was not so palatable. I was called during one of my exams that my ponds have been flooded. It looked as if my world and my entire future were falling away, but thank God for His grace.
To avoid future occurrences, I made enquiries about insurance companies that could insure my catfish farm but only one company was ready to do this and that company belongs to the government. The company gave me stringent requirements that I could not meet so I decided to look elsewhere. Many catfish farmers have lost their means of livelihood, some are sick and some are even out of business due to the effect of annual flooding in the country.
Be it as it may, you as a farmer cannot leave your goal post without a goal keeper. If there is no insurance company to insure your farm and the government is not ready to work on the existing drainage, you must come up with creative ideas to protect your means of livelihood from impending flood. Don’t forget that government is not ready to compensate anyone for any loss due to carelessness. As we prepare for rainy season, you can protect your farm with little unrelenting effort. Below are few suggested ways you can use to protect your farm from flood:
1. Sand Bagging is one of the most widely acceptable ways of protecting your ponds and properties from the effect of flood. I was surprised to see, on CNN, some developed countries of the world using this same method to stop the spread of flood to the surrounding environment. Sand bags have been used several times on my farm to protect my ponds from flood. It involves putting sand in bags and arranging the sandbags skillfully around the dikes of your ponds. The only shortcoming of this method is that sandbags must be replaced periodically because heat can wear them out.
2. Well-Channeled drainage is the one that is well constructed with right depth and proper width. Try as much as possible to remove any plant and solid waste that can obstruct the flow of run-off. Removal of obstructions from your drainages should not be limited to your farm. Check the mouth of bridges not too far away from your farm. I have discovered that most of the local floods in the past are due to blockages at the mouth of bridges. This must be done on a regularly basis.
3. Construction of Embankments and Thick Dikes in an area where erosion from run-off is severe will go a long way at ensuring your pond is protected from flood. These kinds of dikes and embankment can only be constructed by earth moving equipments. The use of machine is important so as to ensure that your dikes and embankments are well compacted to reduce the effect of erosion. Plants like carpet grass can be planted on your dike to reduce the impact of direct rain fall. Also, a concrete embankment can be constructed where earthen dikes will not work. The only drawback on the concrete embankment is the high cost involved but it lasts longer.
4. Surround Ponds with Wire Mesh when you are not sure of your pond safety from flood. Though this method will not protect your pond from flood water entering your pond but it will not allow your fishes to be carried away in flood. Wire mesh is constructed around the pond the same way barbed wires are used in fencing. Some wooding\metal poles of about two meter long are erected around the pond depending on the size of your pond. After which the wire meshes are spread and coupled around these poles. The advantage of this method is that your fence of protection can last for years and requires little maintenance season in season out. The initial overhead could be so high in this method.
5. Proper Netting of Pond is similar to the use of wire mesh. It requires setting nets on your pond by those who are skillful in that area. Netting will not only protect your fishes from predators, it will also ensure that your pond is protected to some extent in case of flood. The security of your pond is only guaranteed if the netting is properly done and no part of the net is torn. However, mortality may increase when runoff water enter into netted pond because net will hold fishes that want to escape leading to their death. It must be noted that net need to be changed at the end of every season due to wear and tear.
6. Constant Removal of Sand Deposit will ensure that your drainage is spacious and allow free flow of runoff. This must be done regularly whenever need arises.
7. Keep your Pond Surrounding Clean from bushes, trees and other obstructions that will not allow you to see the situation of your dike. At times, part of your pond dike might have collapsed without you knowing because of bushy environment of your pond. Clean pond environment will help you to observe the situation of your pond at a glance and repair any part that needs repairs. To ensure you don’t spend too much on bush clearing, water friendly herbicide can be sprayed carefully.
8. Proper Handling of Pipe Networks will help you to prevent flood water entering your ponds through either inlet or outlet pipes. Cover both inlet and outlet pipe when leaving your farm daily, especially in a flood prone area. Be extra careful when you are making spaces through your dikes to fix pipes. If the soil dug out of the dikes is not properly replaced and well compacted, runoff might find its way to your pond through same spot. I will like to say that the best time to do your pipe layout for existing ponds is dry season. Pipe networks can be put in place for your new earthen ponds when construction is still in progress.
9. Construction of Ponds on Water Ways is not encouraged. Always keep a good distance from catchment areas of water bodies. You can always channel water through pipe networks into your pond. Avoid loss of your fish stock due to careless construction of ponds.
10. Ensure Proper Layout of Pond to avoid direct collision of runoff with a pond that is not in line. While laying out your ponds, provide enough space for storm water to flow freely. Make sure that every obstacle on the water path is removed.
11. Usage of Used Tires to Strengthen Weak Dikes has been found effective. You can also use the same method to protect your weak dikes. It is very cheap and so much reliable.
12. Don’t Take Anything for Granted. Do all minor repairs as at when due. When flood in your area is becoming uncontrollable, please leave. Never risk your scarce resource.