Urban Project to Support Wildlife

During this year's rainy season, the residents of North Pleasanton are definitely more aware than any others of the flood control improvements completed by the developers of Hacienda Business Park. These improvements have eliminated the annual flooding on Hopyard Road, Old Santa Rita Road and the properties adjacent to Highway 680 that had plagued the area for decades. Two of the new canals which are designed to control flooding are also undergoing a less visible improvement; a re-vegetation project designed to provide a wildlife corridor which will allow the movement of native wildlife from the ridgelands through an urban area, and encourage the nesting and proliferation of native birds.

The two canals are Tassajara Creek located within the site of Hacienda Business Park, and Arroyo de la Laguna between Bernal Avenue and Highway 680. POD, Inc., the award-winning landscape architects for Hacienda Business Park, are working with the Alameda Flood Control District and the Department of Fish and Game to coordinate the re-vegetation process.

"This type of work has been a much neglected science," reports Stan Heacox, landscape architect and POD, Inc. associate. "Inventories of existing plant life were taken before the widening of the canals began, and the Department of Fish and Game has a list of specific plants which are indigenous to the area. But very few nurseries are able to supply this type of native plant life."

The final list of plants to be included in the re-vegetation included native trees such as Valley Oak, Big Leaf Maple, Boxelder, Cottonwood and Interior Live Oak. Shrubs include Toyon, Wild Lilac, Dwarf Coyote Bush, Blue Elderberry and several species of Willow. To meet replacement ratios specified by the Department of Fish and Game, 1,007 trees and 19,252 shrubs have been or are scheduled to be planted along the two canals.

Many of theses plants have had to be started from seeds or cuttings and can take a year or more to mature sufficiently to be transplanted. POD, Inc. found a local supplier, Pacific Nurseries of Sunol, which was willing to undertake the coordination of the seeding project. They located many small nurseries throughout the state who specialized in certain varieties of native plants and their propagation and contracted for them to raise the required seedlings. "Preparing to re-create a typical ecosystem of a river corridor was a major undertaking," says Heacox. "But it was important to select plants which would support a natural food chain if wildlife is to be encouraged."

Enough seedlings were ready to plant at Tassajara Creek last fall, and Arroyo de la Laguna is scheduled for planting this spring. At Tassajara Creek, the plantings will create a 100' wide corridor with no human access, other than for maintenance. "At maturity, the trees will be from 30' to 80' tall and the shrubs from 3' to 10' tall. In addition, roosting poles for bird species such as hawks and owls will be provided to encourage the birds to locate here until the trees are tall enough to provide them the height they prefer for roosting," says Heacox.

The plants should be fairly well established in 3 years, productive in 5 to 10 years, and mature in 15 to 20 years. Wildlife native to the area includes small rodents, jackrabbits, pheasants, eagles, hawks and egrets. "Since construction of the park has begun," says Heacox, "crews have also reported seeing the rare blue heron."

Through the Hacienda Business Parks Owners Association, the re-vegetation project will be maintained for two years at Tassajara Creek, and five years at Arroyo de la Laguna. After that time, the Alameda County Flood Control District will assume the maintenance responsibility.

"It has been a very exciting and challenging project to work on," relates Heacox. "It will be very interesting to watch the maturing of this natural habitat, and see which birds and animals take up residence here in the park or use the corridor for forage."

To see a reproduction of the original article and edition of Pleasanton Pathways, visit: February 20, 1984 Pathways.

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