The city of Maple Grove measures water level regularly throughout the open water season, and the latest measurement can be found on the DNR website:
Anyone interested to know the current lake level can also check the gauge by the culvert on the north end of the lake at Weaver Lake Rd. The gauge is surveyed every year, and readings are cross-checked for accuracy against the known elevation of the concrete culverts. The surveyed gauge zero point for the 2021 season is 886.55'. Add this number to the gauge reading to compute lake elevation. For example, 886.55' + 4.70' (gauge reading) = 891.25'.
Fish Lake water and winter ice levels are determined by the amount of precipitation. Snow and rain enter the lake directly and through runoff from surfaces, including the city storm sewer system. During summer rain events, Fish Lake typically rises 2x the amount of rainfall.
Water drains from Fish Lake into Rice Lake through 2 concrete culverts under Weaver Lake Rd. Some water is also lost due to evaporation.
Elm Creek runs through Rice Lake, entering under I-94 and exiting at the outlet dam near Maple Grove high school. Like Fish Lake, Rice Lake also receives runoff from surfaces around the lake, but Elm Creek is the primary source of water coming into Rice Lake.
Drainage from Fish Lake into Rice depends on Rice Lake's water elevation being lower than Fish. The lower the elevation in comparison to Fish Lake, the greater the flow of water coming out of Fish Lake. Flow may also be reduced due to obstructions - beaver dam construction, increasing cattail growth at the lake outlet, and culverts clogging with debris have been topics of discussion between FLARA and the city of Maple Grove in recent years.
Following heavy rains or snow melt, the flow from Elm Creek coming into Rice can be high, bringing Rice lake to a higher level than Fish. When this happens, the flow reverses and water flows from Rice into Fish Lake. Water quality from Elm Creek and Rice Lake is much lower than Fish. To prevent this reverse flow from Rice Lake, the City of Maple Grove closes "flapper valves" in each culvert when this condition exists, and then opens them once the Rice Lake level drops.
The city closely monitors water levels during rain events, and records the lake level approximately every 2 weeks. This data can be found on the DNR website:
The dam and culvert elevations can also impact lake drainage:
Rice Lake dam elevation is 891.0'. Water will no longer drain over the dam when the level gets below this elevation. The city periodically does a "drawdown" on Rice Lake which temporarily reduces dam height and water level significantly below 891.0'
The culverts between the lakes have bottom elevations of 890.81' and 890.84'. This acts like a dam for Fish Lake - when Fish drops below this level, water will no longer drain from Fish into Rice