Summary of Environmental Recommendations, Waterloo Sustaianable Design Workshop:
Dredging: The Cedar River has a sediment problem. Urban and agricultural runoff carry topsoil into the river. As the dam slows the flow of the water, silt settles to the bottom. The area behind the dam fills in with mud, and navigation by powerboats is limited. As long as the river carries the sediment load, we cannot recommend dredging as a sustainable solution. Dredging serves the interests of a very small percentage of the population. It is very expensive, and it is a very short-term solution. Dredging could easily cost $500,000 for an area of one mile long by 100 feet wide by two feet deep. It would have to be repaeted every three to five years, and could be undone by one major storm.
Sedimentation is a problem effecting the entire river. Silt suspended in the water reduces the amount of sunlight penetrating to the aquatic organisms. Oxygen levels are reduced. Sand and gravel needed by desireable fish species for feeding and egg-laying are buried in the mud. To address the sediment problem we recommend watershed management as the sustainable solution.
Conservation practices must be implemented throguhout the watershed. Vegetative filterstrips need to be established along every stream that feeds the river. Responsible erosion control measures must be employed on all construction projects. This is the only real way to control sedimentation and restore the water quality of the river. All concerned agencies and organizations should join in the education campaign to make it happen.
The Dam: At this time it does not appear the dam is going anywhere. It is structurally sound and the city is not likely to spend what it would take to remove it. Therefore, for now anyway, the dam should be exploited as an attraction. The city should consider developments that polace people where they can see, hear and otherwise sense the power of the rive going over the dam. Signage or some means of conveying the historical importance waterpower played in the development of Waterloo should be included.
The dam currently serves two purposes. It keeps the water level high enough for power boating (until the river gets too silted in) and it makes it easy for John Deere to draw water for cooling (until they abandon all downtown operations.)
It is the opinion of the river corridor group that, when the dam deteriorates, it should be removed instead of repaired. The presence of the dam limits the number and variety of ways people can enjoy the river. It alters the natural charcter of the river. And it impairs the ecological potential of the rivr. Removing the dam would reduce powerboating but it would open up the river to improved canoeing, rafting, tubing, swimming, wading, wakling the edge, and fishing with waders. Fishing boats with motors could still be used on much of the river. It is felt that people pursuing forms of recreation are more likely to interact with downtown businesses.
Removal of the dm would imporve habitat for all wildlife and in particular dsireable fish species. Fishing would shift from primarily carp and catfish to bass. This would attract more anglers, anglers more inclined to sleep in a hotel, eat in a restaurant, and shop in a store.
The river would be much more visually interesting with the dam removed. Lower levels would expose a rocky, sandy edge with rocky points out in the stream. Water would swirl around a splash over these points. Natural white water and splashing sounds would result. Emergent vegetation would grow along the edge. Birds, reptiles and other wildlife would follow.
Wetlands: We have learned from experience that confining a river between floodwalls may protect the immediate area from flooding, but it greatly increases the severity of flooding downstream. We also have learned to appreciate all kinds of wetlands for their ability to alleviate flooding. Wetlands provide surface area for excess water to spread into during major runoff events. Wetlands hold the water while it is gradually absorbed into the ground or fed back into the river. As any new land is acquired or becomes available in the river corridor, it should be left in the floodplain or returned to the floodplain to allow for natural expansion of the river during flooding. It should be managed as floodplain woods and wetlands. Wetlands help filter out sediment and other pollutants. They create green space. And they are excellent wildlife habitats.
Center for Energy and Environmental Education
University of Northern Iowa