Lake Tecumseh Weir Project
Overview - Weir - Boat Portage - Environmental Monitoring - Studies - Construction
Environmental Monitoring - Water Levels
Credit: USFWS (Full size PDF - 698KB)
Credit: USFWS (Full size PDF - 461KB)
Credit: USFWS (Full size PDF - 110KB)
The above hydrographs depict water levels in Lake Tecumseh before and after the weir was established on February 22, 2011. These data cover the time period between February 2008 and January 2013. The upper most graph depicts the three years prior to the weir installation and the lower graph depicts water levels after weir establishment. Water levels were recorded every three hours with an automated device placed in the lake. Rapid draining of the lake due to wind tides can have detrimental effects to aquatic life as evidenced by the fish kill in the lake discovered by researchers on September 26, 2008. The yellow or middle line on the hydrograph indicates the elevation at which the weir was built. The weir resulted in a 47% increase in boatable water depths across the lake and reduced discharge of suspended sediment by an estimated 90% . The upper and lower red lines depict the ordinary high and low water elevations due to wind tides. According to these data, the weir was submerged 49.5% of the time since establishment allowing water exchange between the lake and Asheville Bridge Canal. This exchange allows continued flood absorption by the lake and surrounding wetlands with the weir present. It also permits fish to pass over the weir.
March 26, 2013
All images by FWS unless otherwise noted.