Before/After at the Oken Property

Welcome to Before/After, a series where we showcase the long-lasting impact of our restoration work.

In 2017, the Sonoma County Agricultural Preservation and Open Space District (Ag + Open Space) proposed a riparian restoration project on its 76-acre Oken property. The property is located on Petaluma Hill Road, along the northeastern edge of Rohnert Park in Sonoma County. The grassland supports grazing and acts as a bowl for several drainages running down from the surrounding hills. Erosion wasn’t historically a problem, but housing development, the routing of a small stream through roadway culverts and open grazing of the tributaries in recent years had combined to channelize the waterways that cut across the property, creating several steep head cuts.

Before, with active headcuts and erosion

PCI’s biology, design, engineering and planning teams worked together to prepare a plan that would restore the waterways. Their collective vision involved bioengineered repairs, rock grade control, an arch culvert livestock crossing, wildlife firefly fencing and an abundance of willows.

Before urbanization, intermittent tributaries like the ones at Oken would have formed a series of distributary channels that would fan out as they exited the foothills, storing sediment and recharging groundwater. Despite the erosion, an alluvial fan still existed on the property, but it was incised with particularly prominent headcuts. Designers envisioned a willow “sausal” transition for this area (sausal means willow in Spanish, and refers to a thick willow grove). The eroding bank would be re-contoured with soil fill and the disturbed area would be covered with coir blanket and coir mat over native grass seed. A willow thicket would stabilize the slope and allow flows to continue fanning out through use of a bioengineering technique using living willow brush sills and wattles before draining into the main channel. Willow poles would be planted to create the thicket above the sills. At the toe of the slope, along the main channel, two brush sills would be placed with willow wattle anchors.

Willow sausal after construction

PCI’s design plans also called for the construction of three rock stabilization structures. A drop inlet at the downstream end of the swale in the southwestern corner of the property would be protected with a rock basin. Headcuts in the southern end of the property and in main channel toward the center of the property would be repaired. An incised channel segment upstream in the main drainage would be restored with soil fill to create a stable channel bed.

Willow sausal in May 2022

As part of the design process, PCI looked at potential opportunities for additional habitat enhancement, and provided recommendations for wildlife-friendly grazing infrastructure and management of invasive plant infestations.

Construction was completed in 2021; Hanford ARC was the contractor, and PCI’s planning team secured all necessary permits. About 1,000 plugs of native rush and sedge were planted along the newly fenced out creeks by Students and Teachers Restoring a Watershed (STRAW), a program of Point Blue Conservation Science that brings ecological education and opportunities to participate in restoration to local schools.

Willows planted as part of the sausal restoration will be assessed each year for five years after planting. In summer, survivorship and growth of willow plantings will be recorded and general observations of plant health noted. In May of 2022, the sausal area appeared lush and green, and the stabilized waterway showed no signs of erosion.

PCI’s construction crew continues to care for the property by removing invasive thistle, mowing firebreaks, and weedeating around the plantings. When crew members arrived on-site in May of this year, the property’s inhabitants — and original weedeaters — insisted on checking out their equipment.

PCI is hiring!

Join our amazing team of designers, scientists and restoration technicians to take an active role in restoring our natural world. PCI is seeking applicants for several positions, follow the link below for more information.

Careers at PCI

PCIers on the Mill Creek site

PCI at the 39th Annual Salmonid Restoration Conference

We will be in good company this week at the 2022 Salmonid Restoration Conference in beautiful Santa Cruz.

PCI Principal Civil Engineer Luke Walton will be presenting Tuesday at a workshop on Restoration Approaches to Instream Large Wood Augmentation along with our colleagues at Trout Unlimited, Pacific Watershed Associates, the California Department of Fish and Wildlife, and others. Principal Hydrologist Christopher Woltemade will be presenting Friday at 10:30am on High-Resolution Water Budget Hydrology to Support Collaborative Water Management for Salmonid Recovery in the Mill Creek Watershed and Navarro River.  

The theme of this year’s conference is Reconnecting with Resilience, and its central coast location is important to that theme.

“Santa Cruz is home to some of the southernmost populations of wild salmonids left in California,” the Agenda Packet states. “The conference will highlight lagoons, seascape ecology, ocean conditions, life history variation, and feature tracks on drought, climate, and hydrology; and another on physical habitat conditions and food webs.”

You can read more about it here.

First in the State: Cutting the Green Tape at the Garcia River Estuary

In September 2021, Governor Newsom signed Senate Bill 155 which provided a new California Environmental Quality Act (CEQA) statutory exemption for restoration projects. PCI, along with partners at the Nature Conservancy (TNC) and the North Coast Regional Water Quality Control Board, was instrumental in working with California Department of Fish and Wildlife’s Cutting the Green Tape Team to develop the first statewide habitat restoration statutory exemption–for the Lower Garcia River Estuary Salmonid Habitat Enhancement Project.

In the words of Peter van de Burgt, the North Coast Restoration Project Manager for TNC, and PCI alum: “This statutory exemption could not have come at a better time for the Garcia project, and it’s really exciting to have the opportunity to immediately put it into practice. I’m optimistic that the exemption will be an invaluable tool for implementing ambitious restoration projects in a more time- and cost-efficient manner than ever before, which is exactly what we need given the enormity of the challenges we face.”

The Lower Garcia River in coastal Mendocino County is important steelhead and coho salmon habitat. However, winter rearing and outmigration habitat in the estuary is limited due to a history of channelization and simplification for agricultural use, excessive sedimentation from upper watershed land use, and large woody debris clearing. The enhancement project is designed to increase in-channel and floodplain habitat through the middle estuary and expand access to the newly created habitat for salmonids during their most critical life stages. PCI has provided site assessment, design, planning, and regulatory compliance services to TNC for the project.

Our team worked hard to make this use of the new  pathway possible, and we’re delighted to be part of the statewide effort to reduce hurdles for large-scale restoration work! PCI is proud to be part of a community that is committed to increasing the scale and pace of salmonid restoration across California.

We Have Moved!

We can now be found at the following two locations in Sebastopol:

Science and Administrative Office
103 Morris Street, Suite A-5

Planning and Design Office
7151 Wilton Avenue

Continue reading

PCI is hiring!

Join our amazing team of designers, scientists and restoration technicians to take an active role in restoring our natural world. PCI is seeking applicants for several positions, follow the link below for more information.

Careers at PCI

PCIers on the Mill Creek site

Gualala River, Mill Bend Preserve

PCI is thrilled to be working with the Redwood Coast Land Conservancy to develop a Conservation Plan for the 113-acre Mill Bend Preserve. This newly-acquired preserve lies at the mouth of the Gualala River, at the border of Sonoma and Mendocino Counties, and offers spectacular views of the estuary. It is adjacent to the town of Gualala to the north, and Gualala Point Regional Park to the south.  PCI’s work includes assessment of the site’s rich resources, identifying restoration opportunities, and planning public access that protects sensitive habitats.

The Press Democrat – New 113-acre preserve on Sonoma-Mendocino line aims to bolster Gualala River recovery

Two Petaluma parks are moving forward

Petaluma River Park is Funded for Phase 1

The McNear peninsula in the Petaluma River located downtown is in the process of becoming a beautiful art park. As the gateway to Sonoma County it will be what you first see when you enter the county on HWY 101 from the south. For residents and visitors to Petaluma it will offer a great addition to our public open space for recreation and river access. PCI is involved in the design and planning for the project and about to start phase 1 which includes initial public access and shoreline restoration. The park will ultimately be home to many large sculptures and other art installations.

Petaluma River Park secures 1 million to start first phase of construction

Kelly Creek – Putnam Park Extension Project

The Kelly Creek project is moving forward with preparation of the Final EIR. PCI is working with Earth Island Institute and Sonoma County Regional Parks to design a project that includes restoration of the iconic red barns, new trails that connect into the 256-acre Helen Putnam Regional Park, parking lot with restrooms, children’s play area with native butterfly garden, creek restoration and pasture improvements. We are excited to continue design development and planning for the park.

Coming soon details of the 44 acre Helen Putnam Regional Park expansion

PCI design success: Nathanson Creek

Nathanson Creek flows through the city of Sonoma, past schools and homes, on its way to Schell Creek and San Pablo Bay. In the past, it frequently flooded during winter storms. The City of Sonoma, Sonoma Ecology Center, Sonoma Water, and Sonoma County Ag + Open Space worked together to protect and restore a key half-mile reach of the stream. PCI was brought in to develop a restoration design that would simultaneously alleviate the chronic flooding and improve riparian habitat.

The project, completed in late 2018, transformed a flat, compacted, weedy gravel parking lot into beautiful, functional habitat. A side channel and wetland basin were created to provide more room for high flows and to allow for the gradual infiltration of runoff that is so important to water quality. Hundreds of native riparian and wetland plants were planted.

This winter’s robust rains tested the project, and it performed just as planned. Check it out when you are in the neighborhood! The Nathanson Creek Preserve welcomes the public to stroll along this lovely and functional riparian corridor; you can access it from E. MacArthur just east of Broadway.

Ten Mile River salmonid enhancement underway

PCI has been working with The Nature Conservancy since 2013 to
plan, design, and find funding for projects to improve salmonid habitat value in the lower South Fork Ten Mile River and mainstem Ten Mile River in Mendocino County, California. The first of these projects was successfully constructed in the summer of 2018. Read on for local coverage of the project from Fort Bragg…