In a dam removal scenario, the dam removal would be done in a way to minimize the amount of sediment that would be discharge to the lower river. Sediment transport from dam removal will be a one-time event as opposed to the annual sediment loading from within the City and from the agricultural areas upstream. These upstream sources overtime were responsible for filling of the two impoundments.
If the dams are removed, how does sediment from that activity compare to the erosion entering the river from cropland erosion?
Sediment - learn more
- When were the reservoirs considered to be filled in?
- How much sediment would actually need to be removed from Lake George/Louise under optimal dam removal conditions and how much sediment could be locked in place through vegetation and other stormwater management actions/design?
- Is there any human health risk associated with placing reservoir sediment in the river corridor?
- If the dams are removed, how does sediment from that activity compare to the erosion entering the river from cropland erosion?
- Removing both dams will put more sediment in Lake St. Croix. What will be done about this issue?
- If the makeup of the sediment is sand/gravel, is it possible that there is a market where this might be sold for construction and provide cost offset?
- How much sediment would be released from the river channel under optimal dam removal conditions?
- How much of the sediment can be sequestered in the river corridor without hauling out for placement elsewhere?