5.8.3 Regional Infiltration

ProjectLangdon Lake Regional Infiltration
DescriptionImplementation of opportunities to increase infiltration, including but not limited to construction of infiltration basins and devices, wetland restoration, reforestation, revegetation.
Need

The proposed rule requiring new development and redevelopment to infiltrate one inch of rainfall would capture approximately 70 percent of new runoff volume from the watershed. The remaining 30 percent would continue to convey pollutants to Langdon Lake and other resources in the watershed. To minimize this pollutant loading and to minimize new stormwater volumes generated from the subwatershed, regional infiltration opportunities such as wetland restoration, underground storage and infiltration, or native vegetation restoration and reforestation may be necessary.

Prior to implementing any of these options, opportunities in the subwatershed should be investigated for the most cost-effective and suitable locations. Regional infiltration will be focused on those subwatershed units that are expected to see significant new runoff volumes between 2000 and ultimate development.

OutcomeMinimized new pollutant loads conveyed by runoff; minimized new volumes generated by new development; protection of wetland and surficial groundwater hydrology; wetland restorations; conservation of high-value native vegetation and habitat.
Estimated Cost and Funding

Project 1: Improvements in LL-2. Funding source is District capital levy.

Project 2: Improvements in LL-3. Funding source is District capital levy.

Project 3: Improvements in LL-5. Funding source is District capital levy.

$18,600

$100,800

$83,400

Schedule

2009: Identify and construct improvements in LL-2

2012: Identify and construct improvements in LL-3

2016: Identify and construct improvements in LL-5