Upgrades continue at Rockford's Alpine Dam. Here's what's coming in 2024
Rockford is moving forward with the second and final phase of an Alpine Dam rehabilitation and modernization project that will leave it better able to withstand torrential storms.
Here is what you need to know.
Why is Alpine Dam important?
Alpine Dam is an earthen dam located in Reuben Aldeen Park east of Alpine Road. It was built in 1942 to prevent stormwater from flooding Rockford neighborhoods along the northern branch of Keith Creek. If it were to fail during a severe storm, downstream neighborhoods and businesses would flood.
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How much will the final phase cost?
Planned for more than decade, Rockford this week awarded a $2.8 million contract to Pecatonica-based DPI Construction Inc. to complete the project. About $800,000 of the project will be paid for the by the state.
When will the work begin?
Work is expected to begin in the spring.
What work will they do?
The plan is to add a new auxiliary earthen spillway adjacent to the current spillway. Crews will also add a foot of concrete to the graffiti covered main spillway including the slab and walls, the water chute and the stilling basin. The basin would slow floodwater if it were to spill over the dam which is believed to have happened just once in the history of the dam. An additional row of concrete "baffle blocks" are being added to the stilling basin and a drain pipe is being repaired as well.
What previous improvements were completed?
A first phase of the Alpine Dam project was completed in 2021. That included the modernization of a gate system, addition of video cameras, moisture sensors and the installation of advanced stormwater monitoring equipment.
How is it better?
Before those improvements, Assistant Stormwater Manager Jeremy Mitchell said a gate that controls the flow of water into Keith Creek had to be cranked by hand. During a severe storm, a team from public works needed to go out to the dam to raise the gate a foot. It required 52 cranks to raise the gate just 1 inch. Now using video monitoring and an electronic system, the gate can be raised and lowered with the touch of a keyboard from the Public Works Department office.
Will it meet standards?
The work was required to bring Alpine Dam into compliance with requirements for what is called a "high hazard dam" that protects residential areas. A 2007 review by the Army Corps of Engineers after severe flooding in Rockford found the dam was “in poor condition due to its age and does not meet federal design standards.” With the improvements in place, the dam will be in compliance with modern standards and qualify for federal assistance if it were to be damaged.
Jeff Kolkey writes about government, economic development and other issues for the Rockford Register Star. He can be reached at (815) 987-1374, via email at jkolkey@rrstar.com and on Twitter @jeffkolkey.
This article originally appeared on Rockford Register Star: Here's why Rockford is modernizing Alpine Dam at Reuben Aldeen Park
