Dry Creek Helps Water Flow Clean

Richmond Greenway Project Well Underway

By Alan Sechman

Several decades ago, California enacted environmental regulations to end direct piping of pollution into the San Francisco Bay. Yet today, pollutants continue to pour into our precious bay at alarming rates. Prior to modern settlement, the city of Richmond was a combination of mud flats and wetlands with a unique hydrological system that filtered snowmelt and stormwater before it entered the Bay. Upon urbanization, the system was permanently altered.

Our modern stormwater management system (concrete streets, gutters, and storm drains) rapidly ejects rainwater into the bay, without a chance for the water to be filtered by plants and soil or for it to seep into the ground and recharge the water table. This rapid movement of stormwater over land is one of the major contributors to the Bay's high pollutant levels and poor water quality.

Cities and paved surfaces are here to stay. We cannot realistically revert to the pristine habitat that preceded human development. However, there are steps communities can take to mitigate the effects of Richmond's dense urban setting. Two years ago, The Watershed Project adopted a two-block section of the Richmond Greenway with the goal of creating a cleaner Richmond watershed. The original Greenway project transformed the retired Santa Fe railroad into a 3-mile pedestrian and bike corridor. The Watershed Project believes this unique place has major potential for improving our local watersheds.

Our vision is for the Greenway to act as a focal point for the community to experience and learn from nature, while simultaneously demonstrating the benefits of Low Impact Development (LID). With the help of many partners and volunteers, we have already installed a native habitat garden with a variety of drought resistant plant species. The garden is designed to attract beneficial insects and birds seeking food and shelter.

To further enhance the site, we are engineering a dry creek, also called a bioswale. This dry creek will filter out toxic remnants from the railroad. It works by channeling rainwater into a sloped trough and reducing its rate of flow to a slow trickle, allowing time for the water to seep into the soil. Then, the soil and plant roots naturally absorb toxins such as arsenic, lead and mercury. The water that flows from the bioswale to the Bay is much cleaner and safer for fish and wildlife. This relatively simple concept is more cost effective, easier to maintain than water treatment plants, and has additional environmental and aesthetic benefits.

Although our bioswale will only filter water draining from the immediate area, its main purpose is to exhibit the benefits and functional capability of Low Impact Development projects. If replicated at key points throughout Bay Area cities, projects like the bioswale could reduce the strain humans are putting on our waterways and ocean.

As we move forward with this exciting project, we welcome your input and involvement. Please contact Martha Berthelsen at (510) 665-3689 or Alan Sechman at alan@thewatershedproject.org to find out more about the dry creek and how you can get involved.

Rendering created by Restoration Design Group.