Mint Plaza

San Francisco, CA

Mint Plaza is an economic and social catalyst for the downtown neighborhood and a prototype of urban stormwater management best practices.

For years, when this L-shaped alley only served back-of-house and illicit activities, it was seen as an opportunity site to anchor a new network of open spaces, for pedestrian connections from Union Square into the South of Market District. Essential to this effort was a public-private partnership that resulted in the first privately-funded conversion of a city street to a public plaza. Today, Mint Plaza is a bridge between cultures and communities, a public urban stage serving an incredible cross-section of San Francisco.

Seeing the potential for stormwater management, CMG led the design of a system that could navigate the complex infrastructure found below city streets. The reproducible system is presented as a model of sustainable infrastructure by the SF Public Utilities Commission. The plaza surface is formed by two gently sloped planes, meeting at a slot drain that directs stormwater into two gardens. Each planting area functions as a filter for rain runoff, through which water percolates into the sandy soil of the historic Bay edge. By retaining and infiltrating stormwater on-site, the plaza reduces stress on the city’s combined sewer system, helping to protect the Bay from wastewater discharge. The project also includes one of the first Silva Cell installations, a modular system to support paving and optimize soil volume for tree growth and site stormwater management.

Throughout the plaza, the adaptability and variety of seating allows visitors to have more agency over their experience. Bearers of bag lunches give way to professionals taking calls, photo shoots, foot traffic for Blue Bottle coffee, and people simply pausing for a moment in the urban oasis. Programming throughout the year is facilitated by Friends of Mint Plaza, who bring concert series, food trucks, farmer’s markets, performances, and other events to the city at the plaza.

In 2010, Mint Plaza was awarded an EPA Smart Growth Award for Civic Spaces.