What is Green Infrastructure?
Green Infrastructure is a shift from gray, or traditional, storm drain infrastructure-- where stormwater runoff flows directly into the storm drain and then the receiving water-- to a green, more-resilient and sustainable system. Green Infrastructure uses vegetation, soils, and natural processes to manage stormwater, and slows runoff by dispersing it to vegetated areas, by harvesting and using the runoff, and by promoting infiltration and evapotranspiration.
Green Infrastructure Plan Development
Why is Redwood City Developing a Green Infrastructure Plan?
On Monday, April 22, the City Council approved a progress report on the development of a Green Infrastructure (GI) Plan and provided input on the Plan development. The Plan seeks to reduce pollution in stormwater flowing to the San Francisco Bay through the implementation of Green Infrastructure improvements on private properties, in the public right-of-way, and through large scale capital improvement projects. The plan will use different implementation tools requiring stormwater treatment on a wider range of development projects including new residential homes, new commercial buildings, and substantial commercial remodels. These policy decisions seek to use the existing local development standards definitions to require more projects to provide onsite treatment of stormwater than what is already required by the Municipal Regional Permit (MRP) and also require Green Infrastructure improvements in the public right-of-way for new commercial buildings and subdivisions. These requirements are in response to the unfunded mandate through the MRP, as required by the California Regional Water Quality Control Board. The City must establish a plan to meet these requirements, and depending on the elements of the plan, the burden to avoid pollution in stormwater will fall on private property owners and City taxpayers.
What are the elements of the Plan development?
In May 2017, the City Council adopted a Resolution (here) approving the Green Infrastructure work plan. The work plan is a framework that outlined the schedule, budget, and tasks, and prioritized areas for potential projects necessary to develop and implement a Green Infrastructure Plan. The resolution included the City Council's commitment to the Municipal Regional Permit goals. As outlined in the work plan, and required by the Municipal Regional Permit, the City Council must approve the City's Green Infrastructure Plan before June 30, 2019.
In May 2018, City staff gave a presentation to the City Council's Utilities Sub-Committee outlining the results of a preliminary analysis by the City/County Association of Governments of San Mateo County (C/CAG) regarding what was needed to meet the goals of the Municipal Regional Permit, which include the additional goals of the Green Infrastructure Plan. Currently, staff is working with C/CAG to develop a regional project concept that would serve Redwood City, Woodside, and other surrounding unincorporated areas within San Mateo County. The conceptual project is a 2.6 acre infiltration gallery underneath McGarvey Field at Red Morton Park that would divert stormwater from the Redwood Creek culvert that runs through the center of the park.
The project would capture a substantial drainage area of approximately 1,600 acres, cost about $40 million, and would serve to meet 93% of the Municipal Regional Permit goals based on the current modeling through 2040. To meet the Municipal Regional Permit goals, staff researched more methods and recommended the following policies to the City Council :
- Require stormwater treatment on a wider range of development projects, including the ones mentioned above
- Require developers of large projects to install green infrastructure improvements in the right-of-way in order to treat stormwater flowing along the frontage proposed development site
- Require stormwater treatment on an increased number of building remodels
What are the benefits of Green Infrastructure?
Traditional gray infrastructure is piped storm drainage systems that carry stormwater runoff straight to the Bay and other bodies of water. In contrast, green infrastructure reduces and treats stormwater at its source by slowing, capturing, and filtering stormwater. Green Infrastructure is a more resilient, sustainable system that slows runoff by dispersing it to vegetated areas, which harvests and uses the runoff. It promotes infiltration and evapotranspiration (evaporation and plant transpiration), and uses bio-retention and other natural practices to clean the stormwater runoff before reaching creeks or the Bay.
Green Infrastructure can also mitigate flooding by slowing and reducing stormwater discharges. To read more about the benefits of Green Infrastructure and how it is used to benefit not only stormwater management, but also environmental health and the community, go here.
Potential Multi-Agency Collaboration
With the City Council's direction for the policy changes, staff will create a Green Infrastructure Plan that will adequately identify how the City intends to meet the goals of the Municipal Regional Permit. Staff expects that each of the elements, including the regional Red Morton Project, needs to be incorporated in the Plan to meet the required goals. San Mateo County has shown interest in the regional project and is collaborating with City staff to apply for grant funding for project design and construction. Staff anticipates seeking further direction from the City Council on forming a partnership with the County and the Town of Woodside to pursue the project after the conceptual design is complete.
Business Community Outreach
A significant and important next step is to discuss impacts of the proposed Green Infrastructure Plan requirements with the City's business community. Staff will prepare the draft Green Infrastructure Plan and seek input from community stakeholders including businesses, property owners, and developers to discuss the Plan and gain input through community meetings this May. Staff will present the draft Plan to the Transportation Advisory Committee, the Parks, Recreation and Community Services Commission, the Chamber Board, several Chamber committees including their Economic Development Committee and Housing and Transportation Committee, and the Downtown Business Group. On June 24, staff will return to the City Council with a final Plan, incorporating input received from these business discussions.
For the business outreach presentation, go here.
August 26, 2019 Staff Report
For a map of existing and proposed Green Infrastructure in Redwood City, go here.
To provide input and feedback contact:
Senior Civil Engineer, Community Development Department