Endangered Fish Habitat & Municipal Water Supply Diversion
This project spanned over 4 years and included a river assessment of ~9 miles for possible fish habitat improvements for species of concern, Roundtail chub (Gila robusta) on the Navajo River above Dulce, NM. That assessment has led so far to ~5 miles of river restoration projects, and reconstruction of the main diversion dam for the potable water supply for the town.
To ensure an adequate diversion of water for the community, the existing dam (piled up river gravel and large rocks) required annual maintenance efforts. The old dam also created a fish passage barrier, impeding the Nation’s efforts at recovery of the Chub. The Nation initially considered a much more expensive concept plan for a concrete structure. In the end the diversion was constructed with large boulders and a series of step-pool weirs extending downstream. Native riparian transplants ensured high function and aesthetics as well as reduced annual maintenance costs. This alternative design provides for natural fish passage and minimizes maintenance time and costs significantly.
Riverbend’s services to the Nation included surveying, hydrologic and hydraulic calculations, preliminary and final designs, construction cost estimates, confirmation of 404 & 401 permit exemptions, project specifications and bid documents. In the implementation phase of the irrigation dam modification project Riverbend was hired as the general contractor, and had construction management personnel onsite each day during construction.