Restoring the San Rafael River

Authors: Kenneth Breidinger

Year: 2010 (xlii)

Abstract

Nine native fish species inhabit the San Rafael drainage including the sensitive Flannelmouth sucker, Catostomus latipinnis, Bluehead sucker, Catostomus discobolus, , Roundtail chub, Gila robusta, , and the Colorado River cutthroat trout, Oncorhynchus clarkii pleuriticus,. Additionally the endangered Colorado pikeminnow, Ptychocheilus lucius, , Razorback sucker, Xyrauchen texanus, , and Bonytail, Gila elegans, , inhabit the lower half of the river. With the exception of the Colorado River cutthroat trout, these sensitive and endangered fishes can be found in the San Rafael River. The San Rafael drainage is a perturbed ecosystem impacted by land and water use and nonnative species. Frequent dewatering, degraded instream habitat and fragmentation of the drainage have resulted in reduced abundances and ranges of native fish. Due to the presence of these fish, the threats posed to them and the high potential for a successful restoration, this drainage ranks among the highest in importance to native fish in Utah. Although the opportunity for a successful restoration is high, the process remains difficult due to complex ecological interactions, competing interests in the drainage and over allotted water resources. The drainage wide scale and complexity of this project prompted the assembly of the San Rafael Restoration Committee to guide restoration efforts, provide technical assistance, and assure that all user groups are represented. Due to funding availability and the obvious effects of tamarisk, Tamarix ramosissima, infestation, removal and revegetation efforts were initiated in riparian and floodplain habitats on three properties owned by the Utah Division of Wildlife along the lower San Rafael River. Currently tamarisk removal has been completed on 752 acres and an additional 298 acres will be treated beginning this winter. Removal and re-vegetation efforts will continue on state owned lands and will likely expand onto BLM property in the future. The first task undertaken by the restoration committee was the drafting of a conceptual restoration plan that contained background information about the drainage, a project goal, and objectives and strategies for meeting the goal. During the drafting of the restoration plan it was determined that more information about the drainage was needed to guide restoration efforts. Fish, bird, bat, and vegetation surveys were initiated in the restoration area to track changes associated with the restoration efforts and establish baseline data. Additionally studies to determine movement patterns and habitat needs of native fish and to determine the history of geomorphologic change and assess the effectiveness of tamarisk removal were begun. The Hatt Ranch diversion was identified as a barrier preventing fish movement into the upstream half of the river and restoring connectivity is an objective in the restoration plan. Several potential solutions were devised to address this problem and a geologic study was contracted to determine the pre-dam location of the river to meet data needs. Currently channel restoration and dam removal is being considered however this portion of the project will not be addressed until a viable nonnative control plan is devised to prevent further nonnative fish invasion into the upper drainage. With the exception of the geologic survey, the above projects are ongoing. The current focus of the restoration project is to determine the minimum flows required to support viable populations of native fish throughout the river. Following this study, strategies to meet these recommendations will be explored. Hydraulic modeling of the drainage currently being conducted by Emery County may identify inefficiencies in water management and delivery that may be used for native fish. Future projects will focus on restoring connectivity throughout the drainage, nonnative control, and achieving flow recommendations.