Agriculture

The largest user of water is the agriculture industry. Efficient water management is essential, especially in dry areas. Isolated farm families traditionally obtained water from nearby streams, springs and wells. Today, vast irrigation projects that carry water great distances are common, and are financed by irrigation districts or through the federal government. In projects of such large scale, hydrologists often are involved in determining the best water supply source.

A hydrologists may design a network of wells for a farm and specify a pumping rate for each well that will minimize interference between wells. Working with other scientists and engineers, hydrologists may help plan a system of dams, canals and ditches based on soil properties, land slope, depth of the water table, climate and other factors.

Improperly managed, the farm can be a source of pollution. sediment from eroded fields can choke streams and silt reservoirs. Fertilizers, pesticides and feedlot waste may leach into groundwater or wash into streams, poisoning plants, fish and wildlife. soil and chemical losses also are costly for farmers. Soil and water conservationists with an interest in hydrology work with farmers to develop plans for control of soil erosion and salinity, and for conservation of water. They examine soil properties such as depth, texture, nutrient context, permeability and erodibility.

To reduced erosion, conservationists recommend areas to be terraced, contour-plowed, or kept permanently vegetated such as streambanks and drainage ditches. Special irrigation techniques save water and improve its distribution over the crops. The construction of farm ponds not only provides a habitat for fish and birds. Hydrologists also monitor local weather patterns to foresee conservation problems before they arise, predict spring and summer runoff, alert farmers to possible flooding or shortages, and develop appropriate conservation measures.