As City Council is aware, the proposed Orange Lake Improvements Project is part of Councils directive to staff for the continuation of environmental projects that have a direct benefit to the City's Pithlachascotee River. Included in the design of this project are three (3) elements mandated by the City's National Pollutant Discharge Elimination System (NPDES) permit. These elements are Water Quality, Flood Control, and Public Outreach.
Historically, Orange Lake has discharged stormwater into the river with minimal treatment. As Council may recall, in 2001 and 2004 Continuous Deflection Separation (CDS) units were installed in the two (2) existing stormwater systems with outfalls at the east side of Orange Lake. These CDS units separate and trap trash, debris, sediment, and hydrocarbons from stormwater runoff prior to the stormwater entering the lake and river. Over the years the CDS units have proven to be an effective tool for improved water quality elements associated with environmental projects. Currently, the City has one (1) large stormwater system and two (2) small stormwater systems remaining that discharge directly into the lake without any pretreatment. The large system includes a 42" outfall on the south side of the lake and incorporates the Downtown drainage basin. The two (2) small systems drain parking lots located to the south and north of the Lake. In an effort to satisfy the water quality element of the City's permit, the installation of a CDS unit in the 42" stormwater system, the installations of two (2) manhole baffle/sump structures in small stormwater systems, the installation of a diffusion system, littoral zone creations, dredging, and the removal of sediments are proposed elements in the design.
Flood Control elements include the design and installation of slide gates to the existing weirs on the west side of the Lake. This modification of the outfall structures will allow maintenance crews to lower the level of Orange Lake quickly in order to provide more storage and reduce the frequency of street flooding in the surrounding area.
Finally, the Public Outreach of the proposed project includes the installation of two (2) boardwalks with overlooks on the west and east side of the Lake that will include nature educational stations.