BROOMFIELD, COLO. — The San Francisco Public Utilities Commission (SFPUC) selected MWH to provide planning, design, and construction management services for the Central Bayside System Improvement project. The contract was awarded as a joint venture with URS, and is a key component of SFPUC’s $6.9 billion Sewer System Improvement Plan (SSIP). The SFPUC has identified three primary goals for the project: provide reliability and redundancy; upgrade the aging infrastructure for seismic protection; and stormwater management by incorporating green infrastructure for community benefits.

Of San Francisco’s 49 square-miles, approximately two-thirds of the total drainage area drains into San Francisco Bay while the remainder flows into the Pacific Ocean. MWH/URS will identify a combination of “green” and “grey” solutions to manage combined sewage discharges and minimize flooding within these urban watersheds. Green infrastructure can include permeable pavement, bio-retention planters, rain-gardens, green roofs and other options as warranted in different areas of the city. Combining these green measures with traditional grey solutions like pumping, storage and conveyance, represents a unique approach that offers improved environmental solutions at lower costs.

“It’s only fitting that San Francisco Public Utilities Commission, which serves a city known for its environmental leadership, should take the state’s first steps toward blending green and grey solutions to manage stormwater,” said Bruce Howard, Americas president of government and infrastructure for MWH. “A deep experience and knowledge of tunneling and sewer systems will help MWH update the city’s infrastructure in a way that minimizes its environmental impact while preparing for the climate of the future.”

The project will address alignment of a conveyance tunnel to carry wet and dry weather flows from the north and central part of the city to the Southeast Treatment Plant. The project will be planned, designed, and constructed to meet six major goals set by SFPUC:

1. Provide a reliable, resilient, and flexible system that can respond to catastrophic events, such as earthquakes and severe rainstorms.

2. Integrate green and grey infrastructure to manage stormwater and minimize flooding.

3. Provide benefits to impacted communities.

4. Prepare the system for the effects of climate change.

5. Achieve a balance between economic and environmental stability.

6. Minimize rate impacts on area residents.

San Francisco is also planning eight “Early Implementation Projects” (EIPs) located in eight different urban watersheds in the city to evaluate the effectiveness of green infrastructure in managing stormwater during the wet season. Results will be used in planning and design of the similar facilities as part of SFPUC’s SSIP.