An Analysis of the Impediments to Spawning Migrations of Anadromous Fish in Virginia Rivers: Final Report
anadromous fish, migration, spawning, Virginia, transportation, striped bass, bass, American shad, shad, blueback herring, herring, James River, upstream, dams, barriers, fish passage, restoration, water quality, upstream migration, Hydropower, culverts
The historic and present ranges of anadromous alosids and striped bass were determined for three of Virginia's rivers. American shad, blueback herring, and alewives migrated to at least Remington (river mile 188) on the Rappahannock River. They ascended the entire length of the York River, reaching at least Milford on the Mattaponi and the entire length of the Pamunkey. The alosids traversed the full length of the James River, reaching above Clifton Forge and Covington. Although striped bass were historically caught in the James as far upstream as Balcony Falls (near Glasgow) and probably as far upstream as shad on the other rivers, it is doubtful that they ever spawned above the fall line on any river. Present ranges for all species are Fredericksburg (Embrey Dam) on the Rappahannock, unchanged on the York, and Richmond (Bosher Dam) on the James. One dam on the Rappahannock River and twelve dams on the James River were identified as actual or potential barriers to the upstream spawning migrations of Virginia's anadromous fishes. Elimination of these barriers by breaching, in the case of unused facilities, or by these construction of fish passage facilities would result in the restoration of 47 miles of mainstem river (a 30% increase) on the Rappahannock and 226 miles (a 200% increase) on the James. Water quality was found not to be sufficiently degraded on these rivers to impede spawning migrations of anadromous fish. The dams identified on the James and Rappahannock Rivers were investigated to assess the feasibility of eliminating them as barriers to upstream migration of anadromous fish, and to project a timetable estimating the probable dates of accomplishment. The Embrey Dam at Fredricksburg on the Rappahannock may soon be modified to permit fish passage. On the James, five dams at Richmond are currently being considered for fish passage modifications; access to an additional 139 miles of the James appears likely by the early 1990s. Access to the remainder of the upper James River is blocked by a series of seven hydropower dams in the Lynchburg area. Passage around this series of barriers cannot plausibly be anticipated for at least 30 years. Biological requirements for passage of the anadromous species, and a synthesis of the state of knowledge of fish passage facilities and fish passage through culverts are included in this report.