Other State or Federal Programs Addressing Non-point Source Pollution

  Soil and Water Conservation District’s Erosion and Sediment Control

The goal of the Erosion and Sediment Control program is to apply conservation systems and practices to the land to reduce soil losses from erosion to acceptable levels. The soil loss guidelines are based upon the concept of “T-value,” or the average annual tons of soil loss per acre “a given soil may experience and still maintain its productivity over an extended period” (Illinois Drainage Law 1997). In Illinois, the T-value is between two and five tons of annual soil loss per acre.

The Illinois Department of Agriculture promulgates guidelines as mandated by the Illinois Soil and Water Conservation Districts Act on April 18, 1980. These guidelines phase in voluntary soil loss limits. They provide a means for encouraging landowners to reduce soil erosion. The goal of the guidelines is “T by 2000” - to reduce soil loss from every acre to its T-value or less by the year 2000.

Although the 1980 program lacks a means of vigorous enforcement, the Soil and Water Conservation Districts work with landowners to reduce soil erosion by changing farming practices. Federal farm legislation passed in 1985 and 1990 require farmers with highly erodible land to plan and apply soil conservation systems to remain eligible for farm program benefits.

How successful has the program been in achieving its goal? The Natural Resource Conservation Service conducts a Natural Resource Inventory (NRI) every five years. In 1982 this survey shows 14.7 million acres of cropland (59.4% of total cropland acres in Illinois) are protected to T. A similar survey is conducted in 1987, and it shows the number of acres protected to T have increased to 16.7 million acres, or 67.7% of total cropland. The 1992 inventory again shows an increase in acres treated to T. About 17.7 million acres, or 73.6% of cropland acres, are at or below tolerable soil loss levels.

In 1994, the Illinois Department of Agriculture works with local soil and water conservation districts and other farm groups to undertake the most comprehensive soil loss survey ever conducted in Illinois. Survey results indicate 17.1 million acres of cropland, or 74.1% of cropland acres, are protected to T or below. In 1995, the survey is conducted again to show 17.7 million acres, or 76.7% of cropland, register below the tolerable benchmark. Survey results from 1996 (Figure 41) show a slight decline in acres below T, to 17.6 million acres or 76.2% (Illinois Department of Agriculture 2001). One study reports that cropland erosion in the lower Illinois River basin drops from 6.1 tons per acre in 1982 to 4.1 tons in 1992 (Wills 1997).

Figure 41: Illinois Department of Agriculture’s Soil Loss Report (2001)

While the “T by 2000” program has resulted in a reduction of soil erosion, the focus of the T-value is to maintain soil productivity. A secondary benefit is to reduce the amount of soil being deposited into the state’s waterways.