Treasure Island is about to be conveyed from the Navy to the City of San Francisco. The closure and conversion presents an opportunity to incorporate sustainable development principles into the redevelopment. Currently, all runoff on the island is discharged untreated to SF Bay. The Treasure Island Water Treatment Project is conducting the research necessary to demonstrate the feasibility and cost- effectiveness of using constructed wetlands to treat stormwater and possibly wastewater as well, while also providing wildlife habitat and opportunities for environmental education and visitor enjoyment.

In April, 2002, the Treasure Island Development Authority issued a Request for Proposal to a potential master developer, requiring a sustainability plan that includes wetlands for water treatment. The task now is to assure that the system will be of adequate size and design and that it ultimately will be approved, funded and implemented. To demonstrate the feasibility, desirability and appropriate design, size and function to the decision makers, the Treasure Island Water Treatment Project produced a comprehensive, two-part cost-benefit analysis.

A Cost-Benefit Analysis of Creating Wetlands on Treasure Island

LSA Associates, Point Richmond CA

Prepared for the Treasure Island Wetlands Project with funding from The San Francisco Foundation and the Rose Foundation for Communities and the Environment
April 2002

Report Summary

This document consists of two studies:

1) Considerations of Costs and Benefits for Various Wetland Types on Treasure Island, San Francisco California
2) The Economic Benefits of Treasure Island Wetlands

The first report, prepared by Philip Bachand, provides a detailed investigation of building three types of wetlands (tidal saltmarsh, stormwater treatment wetlands, and sewage treatment wetlands) that could be combined in several ways. Each type offers benefits that can outweigh its costs. The wetland system considered here includes all three types and totals approximately 40 acres. The two types of wastewater treatment wetlands could result in considerable cost savings compared with conventional engineered approaches to water treatment. A water recycling process based on tertiary treatment wetlands would cost-effectively provide reclaimed water for the island.

The second part of the analysis, prepared by economist James D. Fine, analyzes the potential economic benefits associated with visitor enjoyment of the wetlands. Based on a review of visitor data from comparable Bay Area wetlands and other relevant literature, the report quantifies the spending by Bay Area residents and tourists expected to visit the wetlands, especially for wildlife viewing. Estimated spending ranges from $4 to 8 million annually. The fresh and tidal marsh system will attract visitors year round, and especially during the winter months when migratory bird populations and associated observation opportunities are the highest. Property values can also be expected to increase; land most proximate to the wetlands may command a 28% price premium. Empirical research indicates that visitor spending represents only a portion of total economic value. Mr. Fine concludes that the total economic value of Treasure Island wetlands could be as high as $16 million annually, under the high visitation scenario.

The results of this analysis provide realistic and compelling reasons to design the Treasure Island wetlands complex to take full advantage of its potential benefits -- ecological, aesthetic, educational, recreational and economic -- to be enjoyed by residents of the new neighborhood and visitors from near and far.

Complete copies of the report, which is now somewhat out of date, are available from the Treasure Island Wetlands Project for $8.00 each. Contact gravanis@earthlink.net.

Note: Subsequent to the publication of the Analysis, the likely master developer of Treasure and Yerba Buena islands, TICD, proposed a ten-acre stormwater treatment wetland and a potential 20-acre tidal wetland.

For more information on the two studies included in the Analysis, click on:

Considerations of Costs and Benefits for Various Wetland Types on Treasure Island (2 pages pdf file)

The Economic Benefits of Treasure Island Wetlands (1 page pdf file)