Rebuilding Haiti must start from the ground up, with agricultural education
If there is a water source nearby there are many options for irrigation.
The easiest is to canal or pipe water downhill to your gardens.
It is also possible to lift water to your gardens.
Human powered treadle pumps are a great way to irrigate plots not too far from rivers or with shallow wells:
Older designs include: The Treadle Pump http://www.cd3wd.com/cd3wd_40/UWWKDTU/wp34/PDF/wp34.pdf
Conservation of water is also important on island ground water supplies. Ground water must be replenished especially with high demand agricultural projects. Ground water is replenished when it soaks into the ground. In Haiti’s mountainous landscape there is not much time for it to accumulate unless there are tree roots and grasses that hold it on the mountainside. Desertified land has nothing to hold the water so it even becomes more arid.
The best water conservation measure is drip irrigation, which saves water by getting it directly to the plants roots.