Basin-scale Modeling of Collective Management Practices in Agriculture to Reduce Sediment and Nutrient Inputs into Flood-control and Drinking Water Reservoirs
Abstract
As basins in semi-arid to arid regions of the Western U.S. continue to face extreme water shortages due to prolonged droughts and threats from increasing hurricane storms moving inland, reservoirs become an essential control on the hydrologic regime. However, management of agricultural lands upstream and downstream of reservoirs is often not aligned with reservoir management for water resources, let alone water quality considerations. Agricultural lands can be a source or sink for pollutants and may also be users, generators, or storage parcels for large quantities of water. Similarly, reservoirs have controls likewise, but on the centralized system. While reservoirs are primarily managed from a water quantity standpoint, they inadvertently play a significant role in water quality, especially in agricultural systems. The collective management of these two operationally separate systems may improve water quantity and quality in these systems. In the presentation, we present a Soil & Water Assessment Tool (SWAT) watershed model developed for the Trinity River Basin in Central Texas to explore collective management of agroecological infrastructure and built infrastructure. The model contains high resolution on agricultural lands and lower resolution on urban grounds to help identify priority areas for agricultural management of water quality. The mixed resolution allows the primary decision-making scale on agricultural lands while enabling a large-scale, highly managed basin simulation. As existing reservoirs and reservoir operations are built into the model, we will present the early exploration of how collective management of the agricultural lands and reservoirs in the watershed could advance water quantity and quality goals. We also compare agroecological interventions (changes in crop rotations, addition of cover crops, tillage, implementation of filter strips, and wetlands) with traditional reservoir management operations (release timing, hedging, dredging) to evaluate simulated water quality and quantity sensitivity to each action. The work will bring discussions on the strategies of building eco-environmental-based agriculture-reservoir collective basin management.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.H25Z..02L