A WATERSHED MODELING FRAMEWORK FOR MILITARY INSTALLATIONS: ASSESSMENT OF THE HYDROLOGIC AND SEDIMENT WASHOFF IMPACTS OF MILITARY MANAGEMENT ALTERNATIVES

The Strategic Environmental Research and Development Program (SERDP) identified the need to provide Fort Benning, Georgia (and eventually other military installations) with immediately usable and effective models that can be implemented for compliance and long-term watershed planning and management. The subject of this paper is a SERDP-funded project that focuses on the development of a watershed modeling system for Fort Benning, GA using the U.S. EPA BASINS framework. The objective of this four-year effort is to identify, adapt, and develop watershed management model(s) for Fort Benning that address impacts on watershed hydrology, sediment, water quality and related ecosystem processes and outcomes resulting from military activities and natural resources management. The 2005 Base Realignment and Closure (BRAC05) decisions realigned thousands of additional t roops and hundreds of military vehicles to Fort Benning and other military facilities, increasing the impact of military operations on the base watersheds. Soils within the Fort Benning watersheds, in general, are highly erodible, and a number of streams are currently listed as sediment impaired under the Federal Clean Water Act Section 303(d). The demands of BRAC05 have direct impacts on runoff, sediment and pollutant generation and transport throughout the watershed. Prudent planning is needed using analysis methods capable of linking land disturbance activities to sediment washoff, and instream impacts on water quality and ecological endpoints. During the first two years of this project, a baseline Fort Benning Watershed Model was developed and applied to current watershed conditions. Concurrently necessary enhancements to two of the BASINS models (HSPF and AQUATOX) were identified. Enhancements that have been undertaken include the following: