Projects

CEI completed a watershed management plan and diagnostic watershed study for the Lake Auburn Watershed Protection Commission (LAWPC). The LAWPC is collaboration between stakeholders in Lewiston and Auburn, Maine charged with protecting the watershed of Lake Auburn, the principal drinking water supply reservoir for the communities of Lewiston and Auburn, Maine. Lake Auburn is approximately 2,300 acres in size and is the last waterbody in a chain of four large waterbodies that collect runoff from a 9,600-acre watershed.

CEI completed watershed field surveys, evaluations and provided recommendations for Stormwater Best Management Practices located throughout the watershed to protect Lake Auburn from excessive nutrient loadings. CEI based these recommendations on modeling efforts completed as part of the plan. CEI estimated nutrient and water budgets for Lake Auburn using the AVGWLF model software. This model was used to determine nutrient loadings from the watershed as an update to a watershed management plan that was completed in 2010. These recommendations included both non-structural and structural BMPs to protect the watershed from NPS pollution associated with a mix of urban, highway, residential, and agricultural land uses.

CEI worked with the LAWPC to implement high priority stormwater BMPs and infrastructure retrofits to capture and treat phosphorus and nitrogen loadings from the stormwater runoff to prevent elevated nutrient loadings and potential algal blooms in Lake Auburn and associated chain ponds. CEI prepared conceptual designs to capture floating sediments at a dam which spills into Lake Auburn from the upper watershed. CEI prepared concept designs for BMPs to utilize existing wetland areas to provide additional filtering and removal of nutrients that enter Lake Auburn via a large tributary. Additional conceptual BMPs include gravel road BMPs; sediment capturing BMPs for steep slopes, direct discharge elimination, re-direction and treatment for a busy four lane state highway; accidental spill containment and treatment BMPs for several roads located directly adjacent to the Lake, as well as many other treatment BMPs located throughout the upper watershed.