Summary

The natural habitat of the Metcalf Energy Center's proposed 20-acre site is elderberry savanna, landscape black walnut, agriculture land and Valley oak riparian habitat with an understory of highly disturbed annual grassland that is grazed by cattle. No threatened or endangered plant or animal species are known to inhabit the site or agriculture land.

Construction of the Metcalf Energy Center (MEC) has resulted in the permanent loss of 10 acres of elderberry savanna and 10 acres of agriculture land.

Definition of Biological Resources

Biological Resources includes identification and assessment of the vegetation, wildlife and wetland resources in the Metcalf Energy Center project area and the impact of the project on those resources. Biological resources within the project area include vegetation and wildlife common to the Santa Clara Valley region that occupy serpentine grassland, annual grassland, agriculture land and the riparian habitats along Fisher Creek and Coyote Creek.

Resources at the Site

Prior to construction, the southern portion of the MEC site contained a row of approximately 30 large California black walnut and a patch of Valley Oak trees that extend from Fisher Creek east to the Union Pacific Railroad. The black walnut trees appeared to have been planted because they are in a straight row along the property boundary. The trees are approximately 40 to 45 feet tall and are generally in good condition. Many of the trees on site fell under the definition of significant tree in the Santa Clara County and City of San Jose tree ordinances. The site plan configuration includes a minimum 100-foot setback from the banks of Fisher Creek on the north and west, in full compliance with City of San Jose and Santa Clara County riparian setback requirements. Calpine enhanced the existing riparian habitat along Fisher Creek by restoring wetlands, preventing access by cattle in the Fisher Creek riparian corridor, and by planting over 300 native trees and shrubs in the riparian zone and setback. These activities doubled the existing 4.3 acres of riparian habitat to 8.6 acres.

Wildlife species occurring on the MEC site primarily are restricted to the riparian habitat and large trees on the southern boundary. Wildlife observed on the site include song birds common to riparian communities such as California towhee, scrub jay, white-crowned sparrow, Oregon junco, mourning dove, northern flicker, and black Phoebe. Red-tailed hawk, red-shouldered hawk and turkey vulture were observed foraging over the site. Two golden eagles were observed foraging over Tulare Hill and the hills east of the site. A burrowing owl was observed using one of the underground burrows on the east side of Tulare Hill in February 1999. Common egret, great blue heron, green-backed heron, belted kingfisher and American coot were observed foraging in Fisher Creek during field surveys.

No wetlands were delineated on the proposed MEC site, the soil is well-drained and does not pond water readily. The wetland at the base of Tulare Hill that is supported hydrologically by a natural spring flowing on the cast hillside is outside the proposed construction zone. This wetland was enhanced and restored during construction of the MEC facility.

Resources in the Linear Utility Corridors

The transmission line connects to an existing PG&E transmission tower on Tulare Hill. The habitat at the base of this tower is serpentine grassland and supports native serpentine plant species including dwarf plantain and owlís clover, the food plants for Bay checkerspot butterfly larvae. A PG&E dirt access/maintenance road currently runs through Fisher Creek from the MEC site and extends underneath the towers on Tulare Hill.

Wildlife occurring in the electric transmission line route includes species that inhabit or forage in Fisher Creek such as great blue heron, green-backed heron, common egret and belted kingfisher. The serpentine grassland is forage habitat for coyote and resident or migratory raptors such as golden eagle, red-tailed hawk and burrowing owl. Several underground burrows used by black-tailed hare, California ground squirrel and other small mammals were observed along the dirt access road where the soil is friable.

Vegetation communities within the natural gas pipeline route include non-native annual grassland, landscape, pasture, agricultural crop and riparian habitat along Coyote Creek. The annual grassland in the route is disturbed with non-native weedy species including yellow-star thistle and prickly lettuce. The landscape, pasture, and crop areas contain primarily non-native species. The riparian habitat along Coyote Creek includes tree species such as sycamore, Valley oak, black walnut, cottonwood and boxelder. Understory species include blackberry, grape and annual species. Portions of the area within the route are paved road and parking lot. Wetlands may occur along the portions of the banks of Coyote Creek.

Coyote Creek riparian habitat is a migration corridor for many species of songbirds, mammals and other wildlife. The corridor provides cover for wildlife moving to new forage habitats and provides year-round breeding habitat for the resident species occurring along Coyote Creek. The riparian trees provide nesting habitat for a variety of raptors, herons, and songbirds. Ponding areas within the corridor provide habitat for frogs, toads, turtles, and snakes, which in turn, are prey species for osprey, herons, egrets, raccoons and other predators. The Coyote Creek waterway supports a variety of fish species, including bass, trout, crappie, blue gill, and migratory steelhead and fall-run chinook salmon.

Special-Status Species

No special-status species were observed occurring on the 20-acre MEC site. The closest special-status species is the federal endangered Metcalf Canyon jewel-flower and Santa Clara Valley dudleya, federal Species of Concern Oplerís longhorn moth and burrowing owl and habitat for the federal endangered Bay checkerspot butterfly that are dependent on the serpentine plant communities of Tulare Hill. The federal threatened California red-legged frog, federal Species of Concern western pond turtle, foothill yellow-legged frog, California tiger salamander, and Mt. Hamilton thistle, and proposed threatened chinook salmon, threatened Central Valley steelhead, and threatened Sacramento splittail potentially inhabit the Coyote Creek waterway.

Regulatory Requirements

The U.S. Fish and Wildlife Service (USFWS), U.S. National Marine Fisheries Service (NMFS), and California Department of Fish and Game (CDFG) review proposed projects for potential impacts on special-status species and their habitats that occur within the land and aquatic areas affected by project construction and operation. Calpine is conducted ongoing consultations with these agencies throughout the project design and construction phases to ensure regulatory compliance with the Federal and California Endangered Species Acts, Migratory Bird Treaty Act, California Native Plant Protection Act, and Title 14 of the California Code of Regulations.

In March 2000, a Biological Assessment was submitted to the U.S. Environmental Protection Agency (EPA) concerning nitrogen deposition on the serpentine habitat of Tulare Hill and Coyote Ridge. U.S. EPA forwarded the Biological Assessment to the U.S. Fish and Wildlife Service (USFWS) and National Marine Fisheries Service (NMFS) on March 24, 2000, and thus initiated formal consultation under Section 7 of the Federal Endangered Species Act. On March 7 2001, USFWS issued their Biological Opinion, thereby completing the formal consultation for the MEC project. The precedent-setting Biological Opinion calls for the dedication and management, in perpetuity, of 116 acres of Tulare Hill and 15 acres of core Bay checkerspot butterfly habitat on Coyote Ridge. Calpine has made a conservation endowment exceeding $1 million to fund management and maintenance of the dedicated serpentine habitat in perpetuity.

The U.S. Army Corps of Engineers (USACE), California Regional Water Quality Control Board (CRWQCB) and CDFG also review proposed projects for potential adverse impacts to wetlands and waterways. A CDFG Streambed Alteration Agreement was required for construction of the natural gas pipeline under Coyote Creek, construction of the recycled water supply line, and a stormwater discharge structure in Fisher Creek. The wetlands and habitats within the Fisher Creek and Coyote Creek riparian corridors were avoided entirely by using the horizontal directional drilling method that places the pipeline underneath the land surface.

Environmental Impacts

Construction of the Metcalf Energy Center will result in the permanent loss of 10 acres of elderberry savanna and 10 acres of agriculture land under the energy center footprint.

Habitats that were temporarily disturbed during construction of the gas pipeline include annual grassland adjacent to Coyote Ranch Road and agriculture land west of Monterey Road and the Union Pacific Railroad tracks. Habitats within the Coyote Creek riparian corridor were avoided with specialized construction methods.

Habitat that was temporarily disturbed within the electric transmission line connection tower area includes serpentine grassland that supports the host plants for the federal threatened Bay checkerspot butterfly. Habitats along the gas pipeline and electric transmission line routes have been replanted where necessary.

Cooling tower effluent is discharged to the San Jose/Santa Clara Water Pollution Control Plant (WPCP) for treatment prior to being discharged to San Francisco Bay. The WPCP operates under an NPDES permit that outlines protective measures that will ensure the effluent will be discharged at safe levels for aquatic species, including chinook salmon, steelhead, Sacramento splittail and waterbird habitat in the San Francisco Bay.

Mitigation

If a threatened or endangered species is in danger of harm from construction or operation of any kind of building projects, mitigation measures may be implemented that avoid and/or minimize impacts to the species and their supporting habitats. Mitigation measures may include; protecting certain areas on-site from construction activities with construction zone limits, timing construction activities to occur during non-critical time periods (example: during diapause period of the Bay checkerspot butterfly), restore and/or improve habitats on-site after construction and monitor during construction to ensure no harm will occur to protected species. The most sensitive biological resources within the project area occured in the Coyote Creek and Fisher Creek riparian corridors and on Tulare Hill. Calpine modified the project design to avoid adverse impacts to the biological resources within riparian habitats of the Coyote Creek and Fisher Creek corridors with the horizontal directional drilling method and with a 100-foot setback from Fisher Creek. As described above, Calpine dedicated 131 acres of serpentine habitat and made an endowment in excess of $1 million to cover management and maintenance of the serpentine habitat in perpetuity.