October 28, 2005
Mr. Donald Wiest, Land Use Counsel
Boston Redevelopment Authority
One City Hall Square
Boston, MA 02201-1007
Subject: Groundwater Conservation Overlay District
Dear Mr. Wiest:
Im writing in response to your request for comments regarding the proposed Groundwater Conservation Overlay District. As you know, the Boston Groundwater Trust was established by the Boston City Council to monitor groundwater levels in sections of the city where building foundations are threatened by reduced groundwater levels and to make recommendations aimed at solving the problem. As such, the Trust is the only entity established by the City government with a sole focus on the groundwater issue.
Along with community groups in the affected area, the Trust has long felt that groundwater related zoning restrictions would be an important part of the toolkit needed to combat groundwater depletion. I feel that the current proposal is a very worthy effort to put this in place. I want to thank the Authority, along with the Mayor and the Office of Environment and Energy, for putting this strong plan forward.
I do believe that there are some areas in which the proposal can be improved. As was pointed out at the public meeting held on October 27, the boundaries of the proposed district need some modification. Among wood piling supported structures not included in the original map or a study zone are the Gardner Museum and the main building on the Simmons College campus. The area that includes these structures, as well as the Museum of Fine Arts should be included in the overlay district. This area, extending westward from the Fenway toward Mission Hill, consists largely of filled marshland. Our well network extends into the area; in addition, we receive regular reports from the Museum of Fine Arts groundwater monitoring program instituted in preparation for their major renovation and expansion project.
I would also like to endorse, as I did in my comments last night, the change from a standard based on infiltration to one based on capture. This change will make the code much simpler for applicants to understand and for the Zoning Board of Appeals and Inspectional Services Department to enforce. A requirement for capture of a 1 inch storm, coupled with a requirement that the lowest elevation for the bottom of the storage system be at elevation 7 feet Boston City Base or higher will capture the vast majority of the rain falling on the recharge areas.
One other issue that deserves study is how to assure that a project located in an area where groundwater is currently depressed will have no negative effect if groundwater levels are restored. For example, a newly finished basement that is below 7 feet BCB that is not adequately waterproofed would not cause any further reduction in groundwater if it is in an area where the groundwater is already low. However, if the level is restored by recharge or repair of other infrastructure, the inadequate waterproofing would then lead to a problem. Perhaps some additional language could be added in the standards section to address this.
I would also suggest that the Trust have a formal role in making recommendations to the ZBA as it considers applications under this section of the Code. Because of our specialized charge and expertise, we are in the best position to provide accurate and unbiased information for the Board to consider as it makes its recommendations.
I would like to thank you and Rick Shaklik for the efforts you have personally put into developing this proposal. With relatively minor changes, I think it will be an important weapon in the fight to preserve building foundations in Boston.