This article is from ECHO Asia Note #26
[Eds.’ Note: This series of articles on water management has been reprinted with permission from Thailand’s Natural Farming Magazine and serves as an introduction to small-scale water management. Many of the ideas offered in these articles are consistent with permaculture design principles, which promote farmer resiliency against varying weather extremes. To read more about permaculture options for smallholder farms, please see this “Permaculture in Development” article by Brad Ward in ECHO Development Note #129.]
Introduction
Farmers are people who are directly affected by drought, so it’s important they have sustainable methods of obtaining water for both consumption and use. This is the reason for the “mound, reservoir, and paddy” water management project. This project is the brainchild of Ajarn Wewat Salayagamthon (Ajarn Yak), president of both the Sufficiency Economy Institute and the Agri-Nature Foundation of Thailand.
The mound, reservoir, and paddy model of water management is derived from a concept of His Majesty King Bhumibol Adulyadej—that we must manage rainfall and foster moist forests, which will both preserve water and prevent forest fires. The world is experiencing a water crisis because so little of our forests remain. Regardless, when it rains we must have places to collect the water. The mound, reservoir, and paddy model of water management promotes the following methods of water collection:
• Small reservoirs should be dug, which can act like the holes in the trays used to make coconut desserts, or “coconut dessert wells”. [Eds.’ Note: “Coconut dessert wells” refers to a large dessert pan commonly used in Thailand, which is covered in small divots or retention areas, for the purpose of holding a coconut mixture. To understand this metaphor further please refer to the image at this link.] If everyone created such holes, it would be possible to collect a significant amount of water. On flat land, on the other hand, rice paddies may be dug which will also collect water.
• We must plant trees and create forests on raised mounds. These trees will help absorb water.
• Reservoirs, canals, wells, and creeks should be dug.
• Large reservoirs should also be dug.
It is Ajarn Yak’s belief that these water holes, implemented on a population-wide level, will collectively produce great benefit. The project has now been in operation for two years, and has had more than 700 participants. The project also has a “Drought Prevention Command Center,” which coordinates activities, helps make plans, etc.
Water management can be undertaken in many forms. For example, in areas containing water sources, you can create terraced fields, check dams, and irrigation ditches at the end of rai and fields [Eds.’ Note: A “rai” is an upload field that often terminates downhill in a paddy field.] In areas downstream, the same principles can be used (Figure 1). There must be places to store the
Figure 1. Diagram of water management
water, such as in buckets, tanks, or large earthen jars. Rainwater should be collected for consumption only after the fifth rain, as by this time, the roof will be sufficiently clean. In the old days people would dig wells beside termite hills, because termites have a natural sense of where to find clean water.
Allocating and shaping mounds, reservoirs, and paddies should depend on your natural conditions: temperature, distance above sea-level, climate, clouds, and volume of rainfall. The water-storage capability of a paddy depends on the strength of its dikes. Care must also be taken to stop crabs or mice from digging holes through them.
Rain is not simply water, it also consists of a variety of minerals needed by plants. Notice, for example, that when it rains plants look increasingly lush and vibrant. If rain isn’t collected, when water is later needed, an enormous financial investment will be required.
Collecting water in pools about kneeheight will allow aquatic life to lay eggs and prosper, for example fish and shrimp. Farmers can then use fish droppings as a free, high-quality fertilizer for their rice fields. Moreover, fish and shrimp provide another good food source. Many kinds of fish eat shrimp, plankton, and vegetables, making it unnecessary to buy any extra fish food.
When designing and making calculations for water management on your land, there are several important factors to consider, including: wind, sunlight, rainfall, soil, and people. Management of some of these factors involves scientific understanding and calculatations. However, considerations for people with their own civilization and culture shows that management of the irrigation model must also be built upon a “social science” foundation.
Understanding Water Movement
The mound, reservoir, and paddy model of water management requires that farmers understand the movement of water on their land. In order to do so, they must know the volume of rainfall in their area, or the number of days it rains in one year. In addition, they must also know the amount of sunshine, or the number of days it doesn’t rain in one year.
Furthermore, farmers must take into account the rate of evaporation and the portion and rate of water that will seep into the ground. It’s important to point out that water which evaporates is still of benefit, as it creates a good relative humidity for your plants. The water which seeps into the ground likewise benefits the groundwater, or the water located even deeper down. Digging irrigation ditches, canals, reservoirs, and creeks, therefore, means collecting water that runs out from paddies and wells. If you are able to store 2,000 cubic meters of water per rai of rice paddy (or 5,000 cubic meters per acre), this may look like a lot, but after a season it will probably be dry. However, if you dig irrigation ditches, reservoirs, canals, and wells at the end of your rai and at the end of your paddies, you will likely still have water to use. More than that, these will also contain fish and other aquatic life, as well as wild vegetables that can be sources of food. These can be harvested, sold, distributed, or processed, as you wish, which in turn will lower your food expenses.
Sustainable water management means using all the water sent to us here on earth. It can be kept beneath the house, above the house, in fields, in wells, in natural bodies of water—even underground or in the air. Water management isn’t simply about water, it can also provide food, such as aquatic animals and wild vegetables, and even, possibly, new friends and a little extra income.