Skip to main content
Grazing Lands Research Laboratory

ARS Overview

Situated between Chickasha and Lawton in southwestern Oklahoma, the Little Washita River watershed comprises 611 square kilometers and covers parts of Caddo, Comanche, and Grady counties. The Little Washita River is a tributary of the Washita River, which drains into the Red River on the Oklahoma-Texas border. Hydrological and meteorological measurements of the watershed have been conducted for decades, providing scientists a long-term data source to study soil and water conservation, water quality, and basin hydrology. Currently, the ARS monitors the environmental conditions of the Little Washita watershed with a 20-station network called the Little Washita Micronet. In addition, the Acme and Apache Mesonet sites are located in the northeast and west areas of the watershed to enhance the observing network.

The Fort Cobb Reservoir watershed comprises 813 square kilometers and covers parts of Caddo, Washita, and Custer counties in southwestern Oklahoma. The Fort Cobb Micronet consists of 15 stations, which measure the same variables as the Little Washita Micronet. The Fort Cobb and Hinton Mesonet sites are located on the southern and northern sides of the watershed.

Scientific Research

In 1936, the Little Washita watershed was selected as a part of a national demonstration project for soil erosion control. Since then, continuous observations of the watershed have been taken in a variety of hydrologic research projects. The U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS) began collecting data on the Little Washita in 1961. Their goal was to examine the downstream impacts of Soil Conservation Service floodwater-retarding reservoirs. To that end, a network of 36 continuous recording rain gauges were deployed on the watershed.

Almost two decades later, in 1978, this watershed was one of seven selected for a national project that was jointly administered by the USDA and the U.S. Environmental Protection Agency (EPA). In this case, the project’s goal was to demonstrate the effects of intensive land conservation treatments on the quality of water in the watershed. Although field measurements were reduced from 1985 to 1992, the network of sensors was expanded, upgraded, and re-instrumented in 1994 to measure rainfall, air and soil temperatures, relative humidity, and solar radiation.

The Fort Cobb watershed was added to the ARS watershed research network in 2005 to address research objectives of the Conservation Effectiveness Assessment Project (CEAP). CEAP is a USDA Natural Resources Conservation Service sponsored program, which seeks to quantify the effectiveness of Federal Conservation practices, at watershed scales, to reduce constituents that impair water quality and wildlife habitat.

Facts about the Little Washita watershed

Topography and geology

Climate

For more information, see Oklahoma Climate Data.

Facts about the Fort Cobb watershed

Topography and geology

Climate

For more information, see Oklahoma Climate Data.

Reference