Bitter Creek Drop Structure
The upper reaches of Bitter Creek provides important habitat for genetically pure flannelmouth sucker, a species of concern. This area is also a high priority for WLCI partners because of the influence of these reaches on downstream conditions, which has historically been considered impaired near the city of Rock Springs.
A large irrigation diversion structure near Thayer Junction (referred to as the Bitter Creek diversion structure) is collapsing and needs to be repaired. A new structure will help: improve water quality; stabilize banks and riparian habitats; reduce sedimentation; and serve as a fish barrier to prevent the upstream movement of white suckers and possible hybridization with the native flannelmouth sucker population. Water quality will be improved by reducing erosion and sedimentation associated with the active head-cut. In addition to serving as a fish barrier, the diversion structure is also acting as a stream gradient control point to prevent an incised head-cut from moving upstream and destabilizing/degrading the crucial aquatic and riparian habitat above it.
The primary objective of the project is to replace the failing diversion structure on Bitter Creek with an engineered structure in a more suitable location. The Sweetwater Conservation District has contracted with an engineering firm to provide a design for the new structure and have completed soils analysis to locate the new structure. The Bureau of Land Management (BLM) hydrologist is highly involved with the planning and design.
When the new structure is installed native riparian vegetation will be planted upstream and downstream of the project area to improve bank stability, water quality and quantity, and forage for wildlife species. In the past Wyoming Landscape Conservation Initiative (WLCI) has supported and involved youth in the planting of native vegetation throughout the WLCI area. In 2011 BLM and WLCI planted over 500 trees and shrubs on Bitter Creek for a National Public Lands Day event. WLCI has assisted an Eagle Scout complete the requirements for Eagle Scout by planting willows. There are plans to involve youth in the re-vegetation of the project area. Additionally, The BLM and WLCI have supported efforts to control non-native vegetation within the Bitter Creek riparian areas. The BLM have collected and released the tamarisk beetle on Bitter Creek in an effort to control tamarisk, these efforts will continue into the future.
When the new structure is completed it is expected that it will prevent the head cut from moving further upstream and impacting the flannelmouth sucker through the degradation of stream habitat. The new structure will also prevent the upstream migration of white suckers which have been shown to hybridize with flannelmouth suckers. Water quality and quantity are anticipated to benefit through the reduction in sediment into the stream and improved riparian vegetation.