Limekiln Gulch

The Limekiln Gulch channel rehabilitation project was designed to increase aquatic habitat for salmonids over a range of flow conditions by creating hydraulic and ecological complexity in the form of in-channel and riverine elements. The design elements for the project included mid-channel islands, split flows, side channels, off-channel ponds, alcoves, floodplain, large wood/boulder habitat structures, and riparian revegetation. Like for the earlier channel rehabilitation projects on the Trinity River, the site-specific design features are intended to evolve over time under the Congressionally mandated flow releases described in the ROD.

This project was designed by the Federal Design Group using a multi-disciplinary and multi-organizational approach that focused on including stakeholder input early in the design phase. The TRRP Design Team reached out to local landowners and the riverine community during the planning process to discuss and evaluate design elements and measures that best met the project goals and objectives. Through this collaborative process, several alternatives were formally evaluated using objective and quantitative metrics before an agreement was reached on the best alternative to implement. This more structured design process helped to foster better communication and transparency and created an environment that allowed for new ideas and recommendations.

Further Information:

  • Updated EA/IS and signed Finding of No Significant Impact (FONSI) (pdf)
  • Map of site design excerpted from EA/IS (pdf)
  • Changes to Federal Emergency Management Agency (FEMA) Base Flood Elevations (BFE) based on as-built conditions. These differ slightly from the elevations initially calculated in Spring of 2018 (due to response to comments), but there remains no rise in BFE at insurable structures. [Updated October 2018]
    • Notification from Trinity County on changes for properties.
    • Exhibit A: Completed project with approximate parcel boundaries (PDF map; pending approval from FEMA).
    • Exhibit B: Forecast changes to FEMA Base Flood Elevation at flow modeling cross sections (PDF map; pending approval from FEMA).
    • Exhibit C: FEMA Flood Hazard Zone boundary changes (PDF map; pending approval from FEMA).
  • Online maps (web pages):
    • Aerial photography: [1944], [1960], [1980], [2016] (other years available too – note controls at bottom of screen)
  • TRRP 2016 Annual Report (pdf)
  • Search TRRP online library for “Limekiln Gulch” (web page)