Effects of a hydraulic-loading dam on groundwater upwelling in a northern Michigan river.

Abstract

Dam removal is becoming a growing concern, as many of the dams built during the 20th century are nearing the end of their structural integrity. Many implications of this beyond the economic effects on society, are on the biotic and abiotic factors of the river ecosystem. Dam removal greatly alters the geological structure of streams as well as offer access to exotic species (Stanley, 2003). Dams effect hydraulic cycles in rivers by impounding sediment, and creating groundwater pressure downstream. This study focused on the effects of the Maple River dam in Pellston, MI. Our findings indicated that dams have a significant effect on the change in substrate downstream. This finding implicates loss to biotic habitats for macroinvertebrates and fish rearing their eggs (Lignon, 1995). We examined temperature differences in beds of algal Chara , which have been previously described as indicators of groundwater upwelling (Hendricks, 1988). Our results supported this with the difference in Chara temperatures at the surface versus the hyporheic zone. This dam’s effect on interstitial water patterns has caused various changes downstream and will have various conservation concerns upon its future removal.