Abstract

The proposed route for a new interstate highway traverses the recharge area of a spring-fed wetland. An investigation was conducted to determine whether the potential loss of recharge would significantly decrease groundwater discharge to the wetland. The local ground-water flow system consists of: a) downward saturated flow through a fine-grained, low-permeability unit, b) downward, unsaturated flow through the upper portion of an underlying coarse-grained, high-permeability unit, c) horizontal saturated flow through the base of the high-permeability unit, and d) discharge to the spring-fed wetland and a nearby creek, both of which are incised into the high-permeability unit. The spring occurs where the water table intersects the land surface. A loss of recharge water may result in a lower water table elevation, which could cause a reduction in overall discharge at the spring. Modeling of ground-water flow suggests that spring discharge may be reduced by 8 to 35 percent after the highway is constructed. The reduction is dependent upon highway alignment and drainage options. The most likely scenarios cause an 8 to 13 percent decrease in discharge.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.