y Brenda Erdahl
A 3 ½ year journey to make the water outflow on Maple Lake more reliable has come to an end for the Maple Lake Improvement District (MLID).
On May 17 Bituminous Roadway, Inc. finished construction of a weir across Mill Creek that will help to reduce overly high and overly low water levels on Maple Lake. Mill Creek is a natural channel located on the southwestern side of the lake that flows under State Highway 55 and into Ramsey Lake. It’s also the lake’s only outlet.
In 2019, the area was coming off an extremely high-water summer that had multiple lakes enacting no wake restrictions, MLID President Tom Valenta said. A lot of rain late in the year, when typically, rainfall is at its lowest was causing an assortment of problems, particularly erosion issues along the shoreline.
“That got us starting to look at how we could improve the outflow so when the lake reaches levels too high, it can flow out as quickly as possible,” Valenta said.
After a lengthy process that involved the Maple Lake – Lake Property Owners’ Association, Inc., Minnesota Department of Natural Resources and Stantec engineers among others, on May 13th construction of the weir began. Five days later, the project that had been years in the making was completed.
A weir is a water level control structure that will be used on Maple Lake to maintain the runout elevation. According to Chris Meehan, Senior Principal Water Resources Engineer at Stantec, lake runout elevation is important because it impacts navigation (particularly through the channel into Little Maple) shoreline erosion, water quality, ice damage and flooding.
To determine the height of the weir and essentially the target water level of the lake, the DNR would only consider data points from the last 20 years.
“By looking at the historical data, we came up with the average water height change from May through September,” Valenta said. “While it’s not an exact science, the goal is to maintain that 20-year average.”
This newly constructed weir on Maple Lake is the culmination of a 3 ½ year effort by the Maple Lake Improvement District to help reduce overly high and overly low water levels on the lake.
