Endangered Species Recovery Program

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HABITAT MANAGEMENT FOR RIPARIAN
BRUSH RABBITS AND WOODRATS WITH
SPECIAL ATTENTION TO FIRE AND FLOOD

Unpublished Report

Bureau of Reclamation
South-Central California Area Office
Fresno, CA
21 September 1998
50 pp.

by

Connie Lee Close and Daniel F. Williams
Endangered Species Recovery Program
Department of Biological Sciences
California State University, Stanislaus
Turlock, CA 95382

Executive Summary

This report identifies and discusses issues and presents recommendations on prefire and flood planning for Caswell Memorial State Park (CMSP) on the Stanislaus River, San Joaquin County, California. Fire and flood pose severe threats of destroying the only major remnant riparian community in the San Joaquin Valley and the last refuge for the riparian brush rabbit (Sylvilagus bachmani riparius) and riparian woodrat (Neotoma fuscipes riparia). The riparian brush rabbit is a California endangered species, and both species have been proposed for listing as endangered by the federal government. In addition, the Park is used seasonally or is home to six other threatened and endangered species and several rare and candidate plants, and the communities represented, Great Valley Mixed Riparian Forest, Great Valley Oak Riparian Forest, and Elderberry Savanna, are themselves considered to be threatened or endangered.

The Park is highly vulnerable to flooding because of channelization brought on by levee construction. Lack of vegetation management and long-term fire suppression have resulted in accumulation of great amounts of fuel and decadence of the woody vegetation, leading to a severe threat of catastrophic wildfire. Stakeholders that need to be involved in solutions aimed at reducing the threats of fire and flooding include the California Department of Parks and Recreation (CDPR), Ripon Consolidated Fire District (RCFD), California Department of Forestry, Bureau of Reclamation, U.S. Army Corps of Engineers, Lower San Joaquin Levee District, Stanislaus River reclamation districts, U.S. Fish and Wildlife Service, California Department of Fish and Game, San Joaquin Valley Air Pollution Control District, California Indian Basketweavers Association, and the landowners adjacent to Caswell MSP.

Trails and roads in the Park are mowed periodically and maintained for access and fuel breaks. Yet the trails and road in the undeveloped portion of the park are too narrow to be effective fuel breaks. The existing well and water distribution system are not designed for or capable of delivering the volume of water needed to fight fires. Further, the Park does not have adequate fire fighting equipment on site and Park personnel are not trained in firefighting. Recommendations for lessening fire hazards and fighting fires include:

Providing an on-site water supply to fight fires within the Park is not possible with the existing budget allocations, and may require support from one or more agencies involved in protecting and restoring riparian communities and threatened and endangered species. In addition to the need for a new or upgraded water-distribution system consisting of about 5,000 ft of 10-inch pipe, a new well that is capable of an output of 1,000-1,200 gpm and a 30 horsepower submersible pump are needed. Costs of these and other items identified as needed to develop a quick-response firefighting capability at Caswell MSP are estimated as follows: well, 1,000 gpm pump, 5,000 ft of 10-inch water line, and hydrants, $188,164; firefighting equipment for Park staff, $1,000; clearing and improving access and staging areas for firefighting, $10,000; standardize existing standpipes to accommodate wildland hose and supply 100-ft of hose at each standpipe, $7,545. Other costs associated with environmental assessment, monitoring, and planning are estimated at $15,000. No estimate could be made for the cost of constructing an emergency ingress-egress road from the campground because the road would have to be located on private land, and CDPR must first negotiate with the land owner for an easement.

There are few options in Caswell for reducing the impact of floods on terrestrial animals, including brush rabbits and woodrats. Constructing elevated mounds that would remain above flood level during severe flooding has been explored and the issues identified. These include potential archaeological resources, impacts on the existing natural community by construction activities, potential alteration of water flow, the costs of acquiring and transporting dirt for construction of mounds, and alternate ways of obtaining fill dirt. Though we cannot estimate costs now, we believe the costs and impacts of mound construction may make this alternative impractical, though it should be more thoroughly explored by affected entities. Another alternative would be to direct funds for these activities to restoring and protecting habitat for brush rabbits and woodrats on the San Joaquin River National Wildlife refuge or other public land within the historical range of these species. Costs for locating and mapping areas for refuge mounds and determining the feasibility of constructing mounds are estimated to total about $10,000.

We recommend providing cover and food on levees for animals seeking refuge from floods. This will require the cooperation of the Stanislaus River resource districts and landowners who own the levees. Providing cover can be done in ways that will not jeopardize levee integrity or the ability to inspect levees for erosion and other potential defects. Planting perennial grasses on the levees would provide a source of food for refuging rabbits and reduce or negate the need to use herbicides to control weeds.

PDF Copy: esrp_1998_rbr-fire-flood.pdf

Information Contact: esrpinfo [at] esrp.org