Channel & Weir System
The Chisago Lakes Outlet Project was undertaken in 1986 to provide an outlet for the land-locked Chisago Chain of Lakes. The purpose of the project was to alleviate extremely high lake levels experienced in the early to mid-1980's. Several property owners experienced damage from high lake levels during this time. To alleviate the high water situation, a plan was developed to create channels and build weirs (a small overflow dam used to alter the flow of water) to aid in controlling the flow of water throughout the lake system.
Lake System Water Flow
In general, the lake water flows through the Chisago Chain of Lakes, roughly, to the north from South Center Lake through a channel beneath Highway 8 to North Center Lake.
The Ditch and Weir System Map (PDF) and the Ditch and Weir Maintenance Map (PDF) shows the prominent flow areas for the Lake Improvement District. The flow arrows show the direction in which water flows through the lake system.
The water then flows from North Center Lake west through a channel to North Lindstrom Lake (beneath County Road 20), whereby it flows south into South Lindstrom Lake via a channel beneath Highway 8.
South Lindstrom Lake is connected to Chisago Lake; which has a weir on its north end adjacent to Paradise Park. If the water level is high enough to flow over this weir (a mattress weir, made of concrete blocks), then it will continue to flow northeast through a channel that flows into Wallmark Lake, eventually out-letting into a wetland northeast of Wallmark Lake.
On the south end of Chisago Lake is a ditch or channel leading to a larger weir structure that controls the water flow into Green Lake. When the water levels are considered high, the gates within this weir are opened, allowing water to flow into Green Lake via a culvert beneath Lofton Avenue.
Out Through Sunrise River
The water in Green Lake flows north into Little Green Lake, and then continues north via a culvert under Highway 8 into Lake Ellen. There is a 3rd weir structure on the north side of Lake Ellen, similar in design to the weir structure that controls the flow from Chisago Lake to Green Lake. When the gates are opened in this weir, the water flows north through a long, underground pipe which outlets into Swamp Lake and eventually into the Sunrise River.