Effectiveness of Beaver Dam Analogs as a Restoration Strategy to Mitigate Increased Water Temperatures and Decreased Dissolved Oxygen 1 1 1 2 3 Adam Culbertson , Christopher Johnson , Lily Wetterlin , Andrew Potter , Hannah McIlwain This material is based upon work supported by the National Science Foundation under Grant No. 1 2 3 1701031. Any opinions, findings, and conclusions or recommendations expressed in this material are Geosciences Dept., Salt Lake Community College Swaner Eco-Preserve United States Geologic Survey those of the author(s) and do not necessarily reflect

Overview map of installed BDA BDA Complex 1 Abstract complexes along East Creek. Per the Clean Water Act, East Canyon Creek is impaired for dissolved oxygen (DO) due to decreased water flows, increased water temperatures, and incision (TMDL 2010). Beaver dam analogues (BDA’s) are artificial beaver dams that can decrease temperatures and increase dissolved oxygen by elevating the water Complex 1 Direction of flow table and increasing connectivity between the channel (Pollock, 2014). This study evaluates how newly installed BDAs affect water quality in the Swaner Eco-Preserve portion of East Canyon Creek near Kimball Junction, Park City, Utah. Water quality parameters including DO, total dissolved solids [TDS], conductivity, pH, and temperature were measured in-situ above and below two BDA complex areas before and after installation. Parameters were measured over 24 weeks before and after BDAs were installed in September, 2019. The mean delta of DO increased from 0.04 ppm (n=9) before BDA installation to 0.287 ppm (n=6) after installation in complex 2, Floodplain connectivity after installment of BDA’s (complex 2) Newly installed BDA’s in complex 1 and increased from 0.594 ppm (n=14) to 0.776 ppm (n=5) in complex 1. The mean Complex 2 BDA Complex 2 delta of water temperature increased from -0.11 °C (n=9) before BDA installation to -0.095 °C (n=6) after installation in complex 2, and decreased from -0.027 °C (n=14) to -0.376 °C (n=5) in complex 1. Mean delta values were calculated by subtracting the downstream value from the upstream value. Studies have shown that the full benefits BDAs have on stream water quality can take multiple seasons (Pollock, 2014).

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Background Swaner Eco-Preserve Boundary

Newpark Town Center • East Canyon Creek is on the 303(d) list as impaired, primarily for dissolved oxygen. BDA complexes 1 and 2 were installed October • East Canyon Creek is protected for cold-water aquatic life (Class 3A) under Utah administrative code Installed BDA Complexes and September of 2019.

R317-2-6 (Utah Administrative Code, 2015). The stream is further classified with beneficial uses of Photo by Culbertson, A. Photo by Culbertson, A. 1C, 2B, 3A and 4. (UDEQ 2010). Map by Adam C. • Impairment is attributed to decreased water flows, overgrowth of algae and macrophytes, increased 1 1 2 water temperatures from excessive exposure to sunlight, and river channel incision (UDEQ, 2010). 2 • Beaver Dam Analogues (BDA’s) are “permeable, channel-spanning structures constructed with a BDA’s Installed mixture of woody debris and fill material to form a pond and mimic a natural beaver BDA’s Installed BDA’s Installed BDA’s Installed dam.” (Shahverdian, S. et al. 2019). • In 2019, 2 BDA complexes were installed by the Swaner Eco-Preserve along East Canyon Creek to develop wetland areas in the preserve. • BDA’s allow for increased riparian growth, and this vegetation provides shade that blocks incoming solar radiation that would otherwise warm the water temperatures, leading to cooler temperatures and increased DO availability. (UDEQ, 2010). • A growing scientific consensus recognizes BDA’s as an effective restoration strategy for riparian zones seeing as they reduce stream temperatures, increase dissolved oxygen, elevate groundwater, and increase floodplain connectivity to the river channel (Potter, 2019). Anabranch Solutions (2019). Installation of a BDA in com-

Purpose and Research Question 1 1 2

This study evaluates how newly installed BDAs affect dissolved oxygen and floodplain connectivity in BDA’s Installed the Swaner Eco-Preserve portion of East Canyon Creek near Kimball Junction, Park City, Utah. BDA’s Installed

1. After the installment of BDAs, will DO levels increase at the final site (downstream) compared to the initial site (upstream)? 2. After the installment of BDAs, will water temperatures decrease at the final site (downstream) BDA’s Installed compared to the initial site (upstream)? BDA’s Installed 3. After the installment of BDAs, will floodplain re-connectivity occur adjacent to the BDA complexes?

Methods Photo by Culbertson, A. • Water parameters (dissolved oxygen [DO], total dissolved solids [TDS], conductivity, pH, and Complex 2 before BDA’s Complex 2 after BDA’s (Floodplain connectivity) temperature) were tested above and downstream of the proposed BDA complexes before and after their installment. • Preliminary water monitoring was conducted at 8 sites during the late winter, and summer of 2019 before the BDA complexes had been installed. • Comparisons of upstream (unmitigated) and downstream (mitigated), evaluated the effectiveness of the current BDA mitigation measures. • Mean delta values were calculated to isolate changes occurring within the BDA complex area independent of seasonal trends in parameters such as temperature. • Water quality was analyzed with two meters, an Ecosense DO200A for DO, and the Hanna Hi 99301 TDS, pH, conductivity and temperature. • BDA’s constructed with volunteers using wooden posts, hydraulic pounder, nearby willow branches, and gravel.

UVWA (2018). “A Stream Comes Back to Life.”

Results Discussion • Delta values are upstream DO subtracted from downstream DO • BDA installments led to an increase in DO in both complexes, and a decrease in water temperatures in complex 1. • After BDA installation in complex 3, the mean delta of DO increased from 0.545 PPM (n=14) to • The expected increase in DO and decrease in water temperatures is likely attributed to a combination of Photo by Culbertson, A. Photo by Culbertson, A. 0.776 PPM (n=5). many factors including hyporheic exchange with groundwater, development of deeper water, and decreased . • After BDA installation in complex 3, The mean delta of water temperature decreased from -0.027 °C Conclusions References (n=14) to -0.376 °C (n=5). • The unexpected increase in water temperature in complex 1 is likely due to overbank flooding. This would Bennett, S., Bouwes, N., Wheaton, J. (2019). “BDA Structure.” Anabranch Solutions. The over-used post-assisted BDA recipe. Bledzki, L. A. (2010, August). “Downstream effects of beaver ponds on the water quality of New England first‐ and second‐order .” Wiley Online lead to greater surface area that receives greater solar radiation before hyporheic exchange develops. • The effect on temperature and DO is predicted to increase with the development of wetland area. Library. • After BDA installation in complex 4, the mean delta of DO increased from 0.04 PPM (n=9) to 0.287 Lautz, L. (2018, November). “Restoring stream ecosystem function with beaver dam analogues: Let's not make the same mistake twice.” Wiley Online • The largest effect the BDAs have had on the river system is primarily hydrogeomorphic, leading to expansion of • BDA’s are an effective strategy to increase wetland area and floodplain connectivity in a stream Library. PPM (n=6). Lee, A. A. (2018). “Leave it to Beavers: Evaluating the Potential for Incised using Natural and Analog Beaver Dams.” (Under the wetland area and changing the physical attributes of the stream. system. direction of Dr. Karl Wegmann). Pollock, M., M., Beechie, J., T., Wheaton, M., J., Carol (2014, March 24). “Using Beaver Dams to Restore Incised Stream Ecosystems.” BioScience Ad- • After BDA installation in complex 4, The mean delta of water temperature increased from -0.111 °C vance Access. • Insufficient time has passed to allow for significant and consistent changes in water quality as a result of the • No significant changes in water quality parameters immediately after installation of BDA’s. Pollock, M.M., G.M. Lewallen, K. Woodruff, C.E. Jordan and J.M.Castro (2017). “The Beaver Restoration Guidebook: Working with Beaver to Restore (n=9) to -0.095 °C (n=6). Streams, Wetlands, and .” United States Fish and Wildlife Service, Portland, Oregon. BDA’s installation. The full benefits BDAs have on stream water quality have been shown to take multiple • Water testing will continue during spring and summer of 2020. Utah Division of Air Quality. (2010, May). Total Maximum Daily Load (TMDL) Reports. East Canyon Reservoir and East Canyon Creek Total Maximum • Development of extensive floodplain re-connectivity. Daily Load. seasons to begin taking effect (Pollock, 2014). This is because the essential ecological benefits result from the Utah Department of Environmental Quality, Department of Water Quality (2000, April 1). Total Maximum Daily Load for East Canyon Creek. Gaddis, • The preliminary testing that has been conducted will provide a baseline that can be utilized to help Erika., Lundeen, Kari., SWCA. Environmental Consultants, UDWQ. • Wetland area increased from 0 to a minimum of 1.8 square acres. development of riparian growth and a wetland environment. UVWA (2018). “A Stream Comes Back to Life” Watershed Restoration.. quantify the hydrological benefits that may result from the BDA’s installation.