Kottinger Creek Restoration

Pleasanton, CA

City of Pleasanton
Summer/Fall 2006

In recent years the slowing flow and increase in invasive plants had drastically changed the landscape of Kottinger Creek as it ran through the neighborhood park between Adams Way and Bernal Avenue in Pleasanton, CA. The Friends of Kottinger Creek organization was formed with the goal of restoring the creek. Friends urged the City of Pleasanton to study and ultimately come to the aid of the creek and surrounding habitat. The City of Pleasanton contracted Restoration Design Group to plan and design the improvements and Hanford ARC was contracted to construct the project.

The 1,595 feet long channel was still active and required dewatering. A noise attenuated pump worked around the clock to drain water from a cofferdam installed at the upstream end of the project. The flow was diverted into 4” pipe, across the length of the project and returned to the channel West of Adams Way. The creek was clogged with cattails and other invasive plant species requiring extensive clearing and grubbing. An existing concrete culvert had to be removed. A 48” two-way manhole was installed in place. Nearly 55 tons of concrete were off-hauled.

Hanford ARC then backfilled the existing channel and excavated a new meandering channel and floodplain. The entire site was scraped of soil and sod in preparation of grading.

The existing picnic area was cleared and a new footbridge was installed Hanford ARC worked closely with Drew Goetting and Eric Stromberg of Restoration Design Group in selection and placement of landscape boulders which made the bridge the focal point of the park.

RDG’s design also called for several rock structures utilizing 156 tons of rock, to control the flow and add visual appeal to the new creek. Hanford ARC adapted a 12” bucket with the addition of steel wings to excavate the channel with increased speed and precise accuracy of width and depth of the cut. Following finish grading, the channel banks were hydroseeded with a native seed mix over keyed-in coir fabric.

Over 150 trees and shrubs were planted along with almost 2000 willow and dogwood cuttings to further stabilize the banks and rock groupings.

Native plants such as Coyote Brush and California Wild Lilac, California Wild Rose and Coffeeberry were planted in the mulched garden areas.

The 20,755 square feet of lawn area of the project was stripped, soil amendments were added and new lawn was planted by drill seeding.

To maintain all of the newly planted vegetation, nearly 13,000 feet of irrigation was added with hundreds of bubblers, spray heads and drip emitters.

Site amenities included over 100 feet of new handrails at stream crossings, benches, new stairs and a raised picnic area with plant and boulder landscaping. Hanford ARC maintained plant and lawn establishment on site following construction. After one year of channel maintenance the City of Pleasanton will assume all care of the park.