Water pumps: a factor among many in irrigation

Put yourself in the shoes of an African farmer, an aspiring irrigation farmer. How do you get water (from wherever the water is: underground, river, swampland) to your crops? Actually this is a very difficult problem to solve. In the developed world, you connect your pipe to a municipal pipe, flip a switch, and watch the sprinklers make rainbows above your roses. In an African village: no municipal water supply and no sprinklers.

There's no question that irrigation can greatly increase household food supplies. With our farmers, we use two types of water pumps. 

First, hand pumps. These pumps are great because they allow individual farmers to increase their yields one their own. Clubs work together to plan their farms and sell their crops, but each club member is solely responsible for his own production.

But in some cases, clubs choose to work together in the garden. They plant 2 or 3 acres together, sharing duties among the members. This is often due to a limitted water supply that requires a small area to be used by many people. Still in other cases, the club choose to work together because they are growing food and raising money for a specific pupose, such as for a children's feeding program or an HIV support group.

That's where the second type of pump comes in: windmill pumps. Windmills are capable of pump a lot of water over the course of a day. If the water supply is limitted, such as in the case of a spring, the windmill can collect water at night to be used during the day. A large group, if well organized, can manage the added cost of a windmill pump. And being well organized is actually more important than having good irrigation equipment.

That's why we spend most of our time training farmers on crop management, farm planning, and teamwork. Coupling those trainings with irrigation achieves a multiply effect on yields that can be life changing. And we are seeing those changes at Mziza, Chifuchambewa, Chibanzi, and Nasala. Replicating those results at other locations is our next step.

Nasala: farmers chip in for an early start

The Nasala Support Group are working hard to improve their farms and livelihoods. When the club had no resources to start a tomato garden, members chipped in the little they could to make it possible. Without fertilizer, they have used the compost heaps we taught them to make to get good growth so far.

This humble beginning should grow into much more as they plant onions and maize as part of their irrigation training later this year. The goal with this club is for them to provide enough nutritious food for each member and their families, with some extra to sell. 

Chambwe Windmill 2

Here we go again! Loading the truck with every manner of tool, pipe, and windmill accessory, we headed off to Chambwe, Kasungu to put up the windmill blades and install the pump. 

The windmill prop is 10' in diameter (with the blades it comes to 12'), which is 50% wider than our other windmills.

 Here we are installing the windmill stand pipe on top of the tower. This pipe gives the windmill blades enough clearance around the tower.

 The river is 4 meters below the base of the tower, and 11 meters below the windmill. The water line is 10 meters laterally from the base of the tower.

 Here is the pump at the base of the tower. A large diameter casing pipe is laid to the river's edge to protect the suction pipe.

 The suction pipe snakes its way down the casing pipe. A filter and spring check valve fit narrowly inside the casing pipe. The ends of both casing and suction pipes are inserted into the water.

 Now we install the windmill, sans blades, atop the tower. The main axle is 1" steel bar. The prop threads onto the end and is secured by a bolt.

 Here it is ready for blades.

 And then we bolt the blades to the prop.

 Finally the pumping rod is inserted via the top. In this case the rod is too long to be fitted from the bottom.

 A glimpse back over the garden shows the windmill at the rivers edge and the tank at 2 meters elevation. From the river, the pump must lift the water 6 meters.

 Finally, with the wind vane installed, it is a strange site for passersby.

Chambwe Windmill

Chambwe is a village in Kasungu District, where our irrigation partners at Good Neighbours have been working with farmers to make use of the abundant water supply of the Bua River. A windmill is ideal in this area because it can pump water from the river far up the river bank to a storage tank, thereby extending the range of irrigation. Conventional buckets and treadle pumps are limited to the narrow band along the riverbank.

Last week we built the water tank and installed the windmill tower.

The slab: approximately 12 sq. meters.

 The tank wall: 1.3 meters tall, giving a volume of about 15,000 liters.

Plastering the tank.

 The tower foundation.

 The tower in the clouds: 6 meters above ground.

 Back to the tank for waterproofing.

 And finally, the tank and the land below it to be irrigated.

Windmill Day 2, Chifuchambewa

As we continue to get ready for the irrigation season, we will be finishing out two windmills: one at Chifuchambewa, Salima, and the other at Chambwe, Kasungu.

In the previous post, we saw the tower and water tank slab at Chifuchambewa. Last week, we returned to install a few more components and to build the tank walls.

The windmill stands just at the edge of the wellspring. An adjustable lever is driven by wind, running the pump to the side, in the well. This allows us a stable place set the windmill tower, and for the mechanical advantage to be adjusted to suit our power requirements.

 The farmers are hands-on in the process. Men mix cement, lay bricks, and plaster the wall. Pictured below, women ferry sand from the river to keep the work going without delays.

 Finally, the windmill was raised and installed atop the tower. We will return after 2 weeks to install the blades and let it start pumping water. Meanwhile, farmers are preparing their land, and the tank is hardening.

Windmill Day 1

This is what day 1 of a windmill set-up looks like. On the left, you will see the windmill tower. At right, AWP staff and volunteers mix cement for the slab of the water tank. At Chifuchambewa, farmers will use this windmill to irrigate up to 3 acres.

Loading the Windmill on the Truck

Africa is known for absurd loads on the back of pickups. We just toe the line.