Next wednesday from, 1-2 Pacific Time Earth Guardians will be sponsoring a webinar on beaver effects on streams. You can bet I’ll be sitting in the first virtual row. Thanks Mary Obrien for send this my way!

Wednesday, April 23, 2014

2:00pm (Mountain Time)

Abstract – Beaver are known for their engineering abilities and their impact on water resources. Water is a valuable resource in the arid southwest, and the focus of this study was to evaluate the impact of beaver re-establishment on the water resources of the Jemez Watershed in New Mexico for future state-wide management planning. The Beaver Restoration Assessment Tool (BRAT) was used to evaluate the current capacity of the watershed based on vegetation, baseflow, and flood stream power. The model demonstrated that the watershed is capable of supporting a re-established beaver population and identified the suitable stream reaches for dam building activities. Using HEC-HMS, we captured the hydrologic response of the Jemez River to precipitation by calibrating it to historic hydrographs. Once calibrated, 42 reservoir elements representing beaver dams were added to the Rio de las Vacas region to simulate an initial re-established population of beavers. The results indicate an attenuation of 5-30% of peak flows and an increase in baseflow of 5-15%. Additionally, we calculated the increase of aquatic and riparian habitat from dam construction and pond formation. It was determined that 15 special-status species in the watershed could potentially benefit from beaver activity and habitat creation. The Rio Grande cutthroat trout (Oncorhynchus clarkii viginalis; state-sensitive) could utilize ponds as habitat and take advantage of dams as barriers to non-native trout movements and the New Mexico meadow jumping mouse (Zapus hudsonius luteus; state-endangered, federally proposed) could utilize the increase in riparian habitat bordering ponds. It is possible that the re-establishment of beaver to the Jemez Watershed would allow theses species to expand into previously extirpated portions of their range, highlighting the positive impacts of beaver on water resources in this area of the arid southwest.

Who: Bryan Bird, Wild Places Program Director, WildEarth Guardians