Mark D. Tomer, USDA-ARS National Laboratory for Agriculture and the Environment, Ames, IA, David James, USDA/ARS, Ames, IA and Sarah A Porter, NLAE, USDA/ARS, Ames, IA
There are methods available to precisely map locations where various conservation practices should most effectively improve water quality in watersheds, but these methods have not been brought into a common framework for watershed planning. Herein we propose a framework to apply precision conservation techniques in small (HUC-12) watersheds, emphasizing practices suited to Midwestern agriculture and new sources of data (i.e., LiDAR). In concept, the framework is based on a conservation 'pyramid', with soil building practices forming the base, practices that control water movement within fields and below fields forming second and third tiers, and riparian management practices forming the apex. Practices are classified according to landscape placement (i.e., in-field, below-field, or riparian zone) and flow pathway addressed (surface runoff or subsurface drainage). Matrices help to: 1) identify where runoff can readily enter surface water to prioritize placement of runoff control practices, and 2) classify riparian zones according to which flow pathways (surface and/or subsurface) can be intercepted, so that riparian buffers can be designed accordingly. The framework is meant to be applied flexibly, as it can provide numerous scenarios with combinations of practices that can be evaluated using simulation models and stakeholder feedback. New or alternative practices for which placement criteria can be proposed may also be included. The practices included and specific methods to locate different practices can be varied according to local knowledge, preferences, and resources. This framework leverages new data sources and may facilitate new approaches to apply precision conservation technologies in watershed planning.