City compiles series of questions regarding impact of dam removal; DNR responses printed
1) If planning, funding and construction all meet projected timelines, what is estimated date for the river restoration project to be completed?
If funding is approved, the money will be appropriated to us July 1st, 2020 with a maximum timeline of 5 years to completely finish the project. All projects are different but a typical timeline is 1-2 years for design and permitting followed by 1-2 years/seasons for construction. Two years for construction is ideal as it allows for flexibility in the event of bad weather, high flows or any other issues we may encounter. That leaves about 1 year for any project follow up that may be needed.
2) Would the demolition of the wind mill building be of benefit for a wider rock rapids?
That would be a decision for the city but it would allow a broader view and more gradual side-slopes would benefit public access to water’s edge and rapids.
3) What is the estimated size of the rocks which will be placed in the rock rapids?
Rock sizing will be part of the design process to assure stability but similar rapids use a base stone of 1 to 2 feet in diameter with smaller material filling the voids. The boulder weirs are typically 3 to 5 feet in diameter.
4) The area from the point in the park (where the river flows southwest from the east) back to the east, there are several areas that potentially could fill with cattails.
Cattails are, and always have been a component species of lakes, wetlands, and low gradient rivers. Expanses of hybrid cattail monocultures can become prevalent in reservoirs and shallow standing waters.
The 1870 original survey drawings show marshes (possibly cattail) along the Pelican River directly downstream of Prairie Lake and downstream of the city of Pelican Rapids. Within the Pelican Rapids reach currently impounded by the dam, the 1870 survey shows timber along the river on the south and prairie to the north but doesn’t identify marshes.
The Pelican Rapids dam creates conditions conducive to cattail in the shallow and upstream parts of the reservoir.
Removing the dam will restore Pelican Rapids and higher velocity flows that are not conducive to extensive cattail growth. Similar dam removals have resulted in a channel with a forested or prairie floodplain. Since much of the land along the river will be privately owned, trees and vegetation will be a choice of the respective landowners.
4-a) Will the river be dredged in this area to prevent this?
No dredging of the river is anticipated; once the dam is removed, the river slope will steepen and initiate natural scour and shaping of the river channel as the sand, gravel and boulders of the historic Pelican Rapids are exposed. As the river channel forms within the accumulated sediment, many of the shallow areas of the reservoir will be exposed as floodplain. This happened even during the short reservoir drawdown and low flows that occurred in August of 2017. Flood tolerant terrestrial species including trees and shrubs like silver maple, green ash, basswood, redosier dogwood, and paper birch along with many grass and wildflower species grow in floodplains.
4-b) Will the lower areas be filled?
No, wetlands will not be filled.
4-c) Will the pond to the north of the point be dredged?
The concept design included proposed excavation of a backwater to the north of the park point. Backwaters provide habitat for fish and waterfowl as well as riparian access for landowners along the north side of the river.
5) What will the flow of the river look like under the suspension bridge?
As with other aspects of the restoration, project details will be refined from the concept through the design process. Based on the concept, the view from the suspension bridge looking downstream will be of a pool that will be roughly 75% of the current width. The view upstream will overlook the lower part of the historic Pelican Rapids as it enters the pool and the backwater to the north.
5-a) How much lower will it be beneath the suspension bridge?
The water level will be 9 feet lower than currently exists.
6) Who will maintain the rock rapids? DNR? City?
The rapids will be owned by the city. For similar projects, little or no maintenance has been needed.
7) How much of the current dam can be left in place once the rapids is restored? There have been conflicting answers to this from different DNR officials.
Consistently, since the concept was initially presented, the proposed rapids height has been 5 feet. The current dam is 14 feet high and a high hazard jurisdictional dam. The rapids would no longer be considered a jurisdictional dam. The width of the rapids will need to be refined through the design process.
8) The city will need to plan for a walkway across the river where the dam is now. What will be our options for that?
The Outdoor Heritage Fund focuses on habitat restoration so a bridge would normally need to seek separate funding. At the Breckenridge Dam removal, the county was able to acquire and adapt a historic bridge that was used for a bike and walking trail across the river. Other communities have built walk bridges as part of their park and trail system.
9) What will be the elevations of the river? Where the dam is now? Between the dam and the suspension bridge? Under the suspension bridge? At different points from the park east to the city limits? How much will that vary during the year?
River elevations vary seasonally. The detailed river elevations will be established in the design process. The current reservoir varies around 1,308 feet. The concept design would establish a pool upstream of the rapids that would vary around 1,299 feet extending to upstream of the suspension bridge.
The downstream end of the rapids enters near the point in the park and the river level would rise 9 feet in an upstream direction to the upstream end of the current reservoir or about 4,400 feet upstream of the current dam. Upstream of the current reservoir and dam influence, the river bed would be the same.
The Pelican River is relatively stable due to storage in the upstream lakes. Seasonal fluctuations would be similar to the river downstream of Prairie Lake Dam.
10) What will landowners with new land be able to do to their property? DNR restrictions?
As with land on other public waters, landowners would need to comply with shoreline ordinances and buffer laws. Beyond that, they could manage the land as they wish. Maintaining native riparian vegetation is, of course, important for habitat and erosion prevention.
11) How will the DNR set the high water mark?
It will be the top of the new river bank.