The Tyndall Air Force Base (AFB) drainage system comprises two systems, generally divided by U.S. Highway 98 (US 98) and identified as the Flightline District drainage system and the Support District drainage system. The Florida Department of Transportation (FDOT) constructed and maintains the drainage system for US 98. This system ties into the existing base drainage systems along the highway. FDOT has developed an improvements plan for US 98 that will coincide with the reconstruction of Tyndall AFB.
The Flightline system includes a piped system and a few onsite treatment ponds in the upland areas, and a combination of piped and channelized drainage systems throughout the airfield. Wet ponds are generally not used in the Flightline areas because of Bird/Wildlife Aircraft Strike Hazard (BASH) risks. The Support District’s existing drainage infrastructure consists of an aging piped system that has been poorly maintained, linear surface channels, and scattered dry and wet detention ponds. Because the existing control structures were not studied in detail, the efficacy of the current ponds is unknown.
The onsite soils are highly permeable and the depth to the water table is generally shallow (approximately 2-5 feet below the ground). There are some areas that are more compacted and will require special treatments as described in this section. This creates challenges to designing and constructing dry stormwater elements (sometimes referred to as Integrated Management Practices [IMPs] or Best Management Practices [BMPs]) and will result in the base systems having large areas and shallow depths in order to provide at least 12 inches of separation to groundwater. In addition, there are known contaminant plumes in the ground that should be avoided for surface elements. Finally, there are several cultural heritage sites where grey stormwater infrastructure is not permitted.
Tyndall AFB has an opportunity to improve the performance of the existing stormwater system. Green and natural infrastructure alternatives are integrated throughout the rebuilt installation. These strategies are aimed at improving stormwater quality, reducing capital and maintenance costs, and enhancing environmental benefits, including the management of storm surge.
This stormwater plan was developed based on local and federal stormwater ordinances, and environmental regulations and protections. It expands the stormwater requirements found in the Tyndall AFB Installation Faculties Standards (IFS) and presents criteria for stormwater management associated with an integrated land management approach.
Stormwater system designs will comply with all design and permitting requirements of the Florida Department of Environmental Protection (FDEP) as well as those listed in the Unified Facilities Criteria (UFC):
- UFC 3-201-01, Civil Engineering
- UFC 3-201-02, Landscape Architecture
- UFC 3-210-10, Low Impact Development
Coordination of design and construction with Tyndall AFB staff, agencies, service providers and third-party contractors is critical to the successful implementation of planned improvements. All work is required to be warrantied regarding location and installation of materials in a manner consistent with the intent of the Landscape Master Plan and IFS, and to not create a conflict for installation of adjacent improvements by others. All potential conflicts will be identified by designers/contractors in respective sections of the Compliance Checklist and reviewed by Tyndall AFB Staff.