Cost-Sharing Soil Conservation Practices: Economic Pros and Cons from a Lake Management Perspective

ABSTRACT

This paper compares costs and benefits of strategies to control watershed erosion and sedimentation in Lake Springfield, Illinois, with standard dredging operations to remove soil buildup once it has occurred. Lake Springfield is a 1,635-ha body of water maintained by the city of Springfield for drinking and cooling water, and residential and recreational use. Sedimentation has reduced its storage capacity by 13 percent since the lake was built in 1935. Since 1983 the city has funded soil conservation programs in the lake's watershed. These programs are best management practices (BMPs), and include no-till planting methods, as well as the construction of conservation structures such as terraces, ponds, and grassed waterways. In 1983 the city purchased a no-till planter for $10,000; the equipment prevented soil from entering the lake at a cost of $1.05/metric ton. Cost-sharing grants totalling $105,000 to assist land owners in building conservation structures prevented soil from entering the lake at a cost of at least $6.73/metric ton. In contrast, the cost of standard dredging operations to remove soil already in the lake is $5.16/metric ton. Results of the analysis indicated that reduced tillage is very effective for achieving conservation goals and can be implemented at reasonable cost. On the other hand, BMPs funded under the city's cost-sharing program proved more expensive than standard dredging by at least $1.50/metric ton. Although preventive management has some public relations and aesthetic benefits, it is not cost effective because major sediment inputs occur during infrequent, large storms that cannot be withstood by most BMP structures.