Why are irrigation canals a concern?
Irrigation canals are the main waterways that bring irrigation water from a water source to the areas to be irrigated. They can be lined with concrete, brick, stone, or a flexible membrane to prevent seepage and erosion.
Farm and migrant workers and their families often use canals for bathing and canal water for cooking and drinking.
Irrigation canals can be extremely dangerous, especially for children. They are not safe places to swim, tube, or play. The swift current of irrigation canal water can knock people down, sweep them away, and pull them under the water. People can drown in this fast-moving water.
Irrigation canal banks can be steep and slippery, making it almost impossible for people who have fallen into the water to get out of the canal.
Irrigation canals include grates, screens, and falls, which are drops to lower the water level. They may have culverts that channel water or let it pass under a road. These structures and other devices can be dangerous to people who have fallen into the water.
Irrigation water can be extremely cold. The water can be deep, and there are no shallow spots. It may contain trash or debris. Irrigation water is not safe to drink. There may be pollutants, pesticides, herbicides, or other chemicals in the source water flowing through the canal.
Irrigation field ditches are smaller than canals. They bring water from a farm entrance to the crop field. Water-filled irrigation ditches may breed mosquitoes and other waterborne pests.
The Hohokam people, who lived in Arizona from approximately the years 300 to 1450, are most recognized for building more than 500 miles of irrigation canals. They built canals primarily along the Salt and Gila Rivers between approximately 800 and 1350. The Hohokam had the largest and most complex irrigation systems of any culture in the Americas north of Peru. Some of the Hohokam canal routes are still used today.
The Colorado River is the largest river in the Southwest and a major source of irrigation water. Almost 90 percent of all water diverted from the river is for irrigation use. The river flows through parts of Arizona, California, Colorado, Nevada, New Mexico, and Utah.
In the Southwest, the Navajo Indian Irrigation Project is a water delivery system for Navajo use on lands on or next to the Navajo Reservation. It includes approximately 50 miles of irrigation canals. The original plan was to provide water to 110,630 acres of land. The project is not yet complete.
This description is based on the information found in the Web links listed with this topic.
Web Links from MedlinePlus (National Library of Medicine)
Face Fatal Facts: Drowning Dangers on Agricultural Lands (Washington State Department of Labor and Industries) (PDF — 306.61 KB)
The Dangers of Irrigation Canals (Idaho Health and Welfare)
Water Resource Development Strategy for the Navajo Nation (Navajo Nation, Division of Natural Resources) (PDF — 568.10 KB)
Chemicals in Irrigation Canals and Ditches
Are these chemicals in MY community?
Last Updated: May 21, 2014