How To Harvest Water Using Dam Liners

In conserving water for agricultural use, dam liners are a good choice for water pans. They preserve the water by preventing seepage into the soil, and last for many years in use. This is why when training growers and aqua-culturists on how to harvest water using dam liners in Kenya, there are many considerations.

These factors affect the size of the dam liner, and the thickness to install in your water pan. Others determine where the water reservoir is located, and consequently the dam liner. Water harvesting using dam liners is done for rain roof top water from houses and buildings, borehole water, rain ground run-off water, from the river or lake

 

How to Harvest Water Using Dam Liners

Factors to consider

1. Land size

The amount of water required for half an acre is less than that needed for 20 acres. The latter will harvest more water to irrigate the greater acreage, and the former will have less water harvested. The bigger the volume of water reserved, the larger the dam liner size

2. Location

The amount of rain fall is different in every climatic zone. Growers in the cool wet highlands have just a few dry months in the year, while farmers in the dry zones have more dry months than wet. In regions where the interval between rains is long, larger reservoirs are built for the same acreage as that in the cool wet location. Again, dry locations have very high  water loss through evaporation. In this case, it is advised to set up a shade net over the water reservoir to manage this water loss

3.  Ground Elevation

The farm gradient determines the location of the water pan. Some choose to have it at the lowest part so as to capture run-off water. If it is for crop irrigation, this water is either pumped uphill to a tank from where it flows back by gravity to the crop. Or it is pumped directly to the crop from the water reservoir. Others choose to locate the water pan on the highest point of the farm so that the water, through gravity flows out to the crop. In this case, the farmer does not retain run-off  rain water from the farm. On a flat terrain, irrigation water is physically pumped out to either a high storage tank for onward gravity flow to the crop. Or directly to the crop

 

 

4. Farming System

The size of the water pan will differ for irrigation, compared with aquaculture or livestock production

5. Crop Type

Some crops are more water demanding such as leafy vegetables, than others such as herbs. Then some crops  like onion are densely spaced while others are like avocado are sparsely populated in the farm. This will determine the water requirement

6. Irrigation System

Every irrigation system has it’s own unique water use. Drip irrigation conserves water while overhead irrigation through sprinklers or rain hose kits spends huge water volumes

7. Surface Texture

The surface texture of the water pan determines the dam liner thickness to install. For a smooth surface, a 0.5mm dam liner is ok. Where the surface is stony or rocky, then the 0.75mm or 1mm dam line is better

 

 

 

Before harvesting your water using dam liners, ensure that the water pan’s surface is free of debris as much as is possible. This will be stones, rocks, tree stomps, or sticks. This reduces the danger of your dam liner tearing as a result of perforation caused by the weight of the water squeezing the material against these particles

Trench 0.75M to 1M along the perimeter or circumference of the water pan. This trench is 1ft wide and 2 ft deep. Your dam liner edges will be tucked in here and covered with soil, gravel or stones to anchor it in place. Alternatively, use sand bags along the edges to hold your dam liner in place

How To Harvest Water Using Dam Liners

FAQs

I. How Do You Use A Dam Liner?

A dam liner is a cover on the inner surface of a water pan or tank. This is to keep the water within by preventing seepage into the soil or leakage

II. What is a good thickness for a pond liner?

The best dam liner thickness for a  water pan is determined by the volume of water it holds, and the surface texture