Beautiful Riley Lake. Indeed. Recent rains have filled it to capacity, and then some. In the photo above, you can see the dock just barely above the water level at the City’s public access point.
High water can create problems around the lake. Docks can be damaged. Shorelines can be eroded. Swimmers and boaters can encounter conditions they are unfamiliar with, creating problems of a potentially tragic nature.
Riley Lake has an outlet. The outlet allows water to escape the lake in a controlled manner to proceed through a creek downstream. This is a picture of the culvert that helps drain the lake when it gets too high.
The culvert is running at full capacity in this photo, but sometimes it can get plugged up by debris floating in the lake, like tree limbs, old life jackets, etc. When the culvert becomes plugged, or when the water level reaches an even higher threshold, it will spill over a weir and dump directly into the creek bed. You can see the water spill over the weir in this photo:
What you also see in this photo is that someone has reduced the flow of lake water over the weir by installs dimension lumber in the flow direction of water. The lumber reduces the rate of flow, thereby reducing the natural reduction of the level of the lake. The lumber was installed by neighbors around the lake, not by the City. My staff met with some of them today, and with representatives of the local Watershed District, to discuss what to do about this situation.
The result of the meeting was that the lumber should not have been placed in the weir. But, the reduction in the flow did allow for the more frequent cleaning of a bar screen that discouraged lake debris from getting into (and plugging up) the collection end of the culvert that drains the lake. So that was a good outcome.
End result: The Watershed District said “don’t do it again, but don’t take the lumber out yet either.” We expect the lake to drain down to normal level in another week or so.
