Southgate Beautification and Re-Greening Project
Before 2014, the City of Palo Alto’s Southgate neighborhood lacked curb and gutter systems, which caused deep street ponding during storms. To address this issue, the City installed bioretention areas, pervious pavement crosswalks, and a pervious walkway linking the neighborhood to a major commercial area. These neighborhood features are all examples of Green Stormwater Infrastructure (GSI) — an alternative way to design streets to drain water quickly, capture pollutants, and enhance neighborhood landscaping. The Southgate GSI measures dramatically decreased the frequent ponding, as shown in the before and after images below.
What kind of GSI was installed in the Southgate Neighborhood?
The Southgate Project consists of several bioretention areas and pervious pavement installations throughout the neighborhood. The bioretention areas filter stormwater runoff from the neighborhood streets during smaller storm events. During larger storms, the runoff overflows into street gutters to the expanded underground storm drain system in the southeast corner of the neighborhood.
Bioretention area located at Sequoia Avenue and Escobita Avenue.
Bioretention areas reduce street ponding and beautify neighborhood streets.
Image created by Wetland Studies and Solutions, Inc.
Pervious concrete pavers cover approximately 3,200 sq. ft. of crosswalks and pedestrian walkways in the Southgate neighborhood. These pavers allow water to pass through the void spaces between the solid pavers. During storms, water filters into these crosswalks and then into retention areas underground rather than running over impervious roadways, which can cause street ponding.
Pervious pavement diagram showing typical installation.
The Southgate Project has converted many crosswalks and pedestrian walkways in the neighborhood to pervious pavers.
Where are the GSI measures located?
Below is a map indicating the locations of the bioretention areas and pervious pavement crosswalks and walkways in the Southgate neighborhood. You may view the map’s color chart key by clicking the icon on the top left next to the map header text “Southgate Green Stormwater Infrastructure”. Note that the map shows several areas that are cared for by residents. Read below to learn about how you can get involved!
Southgate Project Updates
In 2020, the City launched a pilot project with the local nonprofit Grassroots Ecology to maintain and update the bioretention areas for better performance. Improvements include amending existing soil to assist with drainage and plant health, replacing rocks with mulch, and exchanging current plants with native and drought-tolerant species. To date, 12 bioretention areas have been updated along Castilleja Avenue near Peers Park, Sequoia Avenue, and along Miramonte Avenue. The final four updates along Sequoia Avenue will be completed in the fall of 2022.
As part of the pilot project, the City and Grassroots Ecology have launched the Southgate Green Streets Stewards program, which will allow Southgate community members to maintain and care for a site after training with Grassroots Ecology. Volunteers will monitor the condition of the bioretention areas and take care of light tasks such as ensuring the inlets and outlets are clear of leaves and debris, removing trash, and weeding. They will also be asked to submit a short form after work has been performed on the site and help report problems with the irrigation system, damage to the site, or other issues.
Interested in becoming a Southgate Green Streets Steward?
Please fill out this short form and someone from the City will contact you.
Please submit questions to greenstreets@cityofpaloalto.org or call (650) 329-2441.
Learn more about GSI measures