HYDROLOGIC MONITORING OF ENVIRONMENTAL RESTORATION PROJECTS

In collaboration with Utah’s Watershed Restoration Initiative and its partners, the Utah Geological Survey is conducting studies to measure changes in hydrology and vegetation resulting from pinyon-juniper (P-J) treatments (i.e., cutting) and a beaver dam analog (BDA) project. Extensive P-J treatment projects aim to increase sage grouse habitat, reduce wildfire risk, and potentially increase local water yield. Successor shrub-grass assemblages likely have lower evapotranspiration rates than P-J forests, so groundwater recharge rates in treatment areas may increase. The BDA monitoring project focuses on potential hydrologic changes due to BDA implementation, particularly stream flow seasonal variations and bank storage, as well as sediment trapping. As appropriate to each study area, we are monitoring spring flow, stream flow, groundwater levels, soil moisture, surface-water–groundwater interactions, water quality, stable- and radiogenic-isotope composition, sedimentation rates, and aquatic, wet meadow, and upland vegetation. Monitoring is established in treatment and control (i.e., untreated) areas having as similar hydrogeology and ecology as possible. Ideally, we establish the monitoring systems at least three years before the treatment to characterize baseline response of groundwater to climate variations under current conditions and monitor at least five years after treatment to measure potential changes in the hydrologic system. Results will (1) aid assessment of the impact of treatments on shallow groundwater systems, (2) demonstrate ecologic benefits of the treatment projects beyond changes to plant communities and wildfire risk reduction, (3) help plan future treatment projects by identifying conditions favorable to increasing groundwater recharge, and (4) help plan future BDA projects by providing data on how stream hydrology may change, aiding project timing, setting expectations for local water users, and planning for water rights issues. Project areas include (1) Tintic Valley and (2) Vernon Creek, both in the Sheeprock Mountains Sage Grouse Management Area (SGMA); (3) Southwestern Grouse Creek Mountains in the Box Elder SGMA; and (3) Montezuma Creek Tributaries in the San Juan Conservation District’s Montezuma Creek Coordinated Resource Management Plan.