Critical Response to Support Recovery of Storm-Damaged Sport Fishery Infrastructure

Built in 1891 and listed on the National Historic Register in 1994, the Roxbury Fish Culture Station is the oldest of five Vermont hatchery facilities continuously producing sport fish. In August of 2011, Hurricane Irene ravaged the northeastern United States, including Roxbury. Failure of a retaining wall on Flint Brook running adjacent to the facility resulted in the subsequent flooding of fish rearing ponds filling them with runoff and debris and rendering them unusable. The 2011 flood event was the third flood since 1998 to impact the station and resulted in unrepairable damage to many of its critical structures.  

We were hired to provide engineering and design services to rehabilitate the damaged portions of the facility. Engineering services included design, preparing construction plans and specifications, obtaining required permits, assisting in the bid process, providing construction observation as well as preparing and submitting as-built drawings. In addition to engineering design services, we outlined biological parameters to aid in the sizing of circular tanks and flow rates required to produce 25,000 pounds of trout annually. The 25,000 pounds included 85,000 catchable-size rainbow and brook trout and 300,000 juvenile salmon (fry) annually for stocking Vermont’s lakes, rivers and streams.  

Overall design efforts focused on providing new influent water treatment, new complementary buildings to house circular tanks (these matched the historic context of the existing structures), effluent treatment for permit compliance, and resilient features to reduce the chance of future floods impacting fish production. State-of-the-art technology includes: 

• Incoming source water features rotating drum filter technology water that provides treatment down to 40 microns before passing on to 40 mJ/cm2 ultraviolet disinfection for pathogen control
• Low head oxygenators to boost oxygen levels for the fish before each of two tank pavilions
• Two tank pavilions housing 20-foot circular tanks for fish rearing have been constructed in place of the ruined outdoor ponds. These new units provide a protected rearing environment that is more efficient at managing water and wastewater than the previous outdoor units. 

The rebuilding of the Fish Culture Station marked the beginning of the last recovery project from the storm that devastated Vermont. More than 3,300 project worksheets were written by Federal Emergency Management Agency in response to the Irene flooding, and the fish hatchery is back at full production after nine years of planning, permitting and rebuilding. Roxbury is now Vermont’s newest hatchery facility, with major improvements to water quality, receiving watershed and fish production.