Williamson Valley RoadFloodplain Analysis
GBE provided professional services to the City of Prescott for this floodplain delineation project funded by the Yavapai County Flood Control District. The study reach parallels the west side of Williamson Valley Road between Shadow Valley Ranch Road and Standing Rock Drive and is approximately 2,167-ft in length. The purpose of the study was to determine floodplain elevations along the study reach and recommend drainage improvements to mitigate flooding of adjacent residential structures.
Coyote Wash Stream Restoration Plan
GBE provided professional engineering services for this project that included stream restoration for Coyote wash. The design included restoration of the equilibrium channel slope. An old stock tank located near the bottom of the reach had raised the channel of the streambed and had created large variations in the energy grade line, causing channel instability and high scour potential. The design included excavations of the channel flowline of over 10 feet. The project restored the equilibrium slope of the watercourse and lowered base flood elevations significantly.
Scissor Tank Dam Breach Analysis
GBE provided professional services for this project that consisted of a breach design to remove the dam from its jurisdictional designation by the Arizona Department of Water Resources (ADWR). The breach was designed to reduce the volume of the existing 163 acre-ft reservoir to below the 50 acre-ft mandated by ADWR. The work included evaluation of stage-storage-outflow relationships for the reservoir, inflow hydrology, reservoir routing, scour analysis and hydraulic analysis of the breach.
Smoke Tree Lane Drainage Improvements
GBE provided professional services to the City of Prescott for this capital improvement project funded by the Yavapai County Flood Control District. The project included evaluation of pavement drainage and outfall conditions along the north end of Smoke Tree Lane. Previously, there was inadequate release of pavement drainage from the roadway. Excess runoff overtops the curb and impacted an adjacent property along the west side of Smoke Tree Lane. The intent of this project was to design and construct a new pavement drainage outfall structure along the west side ofSmoke Tree Lanejust upstream from the problem area. This new outfall structure drains directly to the watercourse paralleling the west side of the road.
Gila Butte Subdivision
GBE provided professional engineering services to the Gila River Indian Community for this drainage assessment in Pinal County. The project included evaluation of existing subdivision drainage infrastructure and recommendations for improvements to alleviate flooding conditions. Based on site reconnaissance, we found a number of offsite capacity issues downstream from the project which were causing problems onsite. This insight provided overall project savings to the Gila River Indian Community.
Drake Cement MSGP SWPPP
GBE was commissioned to develop a Stormwater Pollution Prevention Plan (SWPPP) for both mining and non-mining activities at the Drake Cement plant in conformance with the Arizona Pollutant Discharge Elimination System (AZPDES) 2010 Multi-Sector General Permit (MSGP). The SWPPP included a summary of potential pollutant sources and descriptions of control measures, schedules and procedures. The SWPPP was refined through design review meetings and was developed in a 3-ring binder to allow continued refinement by the operator based on changing field conditions. Electronic templates for monitoring and inspection reports were provided to enhance the usability of the document.