The Flatwater Group led a team to rehabilitate the Pine Lake dam for the Pine Lake Homeowners Association in Lincoln, Nebraska. This 20-acre reservoir was constructed in 1961 and was last drained in 1997 for a sediment removal project when the watershed was a mix of agriculture and residential.
A topographic and bathymetric survey was completed and supplemented with LiDAR data to quantify submerged and aerated sediment accumulation and identify 55,000-cubic-yards for removal. A continuous time Soil and Water Assessment Tool (SWAT) model was developed to evaluate long term watershed and sediment yield to inform future management of upstream sediment ponds.
To evaluate storage capacity and spillway proportioning of the reservoir, a SITES hydrologic model of the reservoir was developed using SCS curve number methodology and NOAA Atlas 14 climate data. Assessment of the dam recommended replacement of the principal spillway conduit, which was designed to meet current criteria for a Significant Hazard dam.
Potential future project work includes lake sediment removal and watershed improvements to stabilize incoming stream channels as well as removal of sediment from detention structures upstream of the lake.
Project Photos
