GROTON — The Office of Planning and Development Services is tentatively planning to hold a public hearing by the Zoning Commission Nov. 3, 2010, on proposed changes to the town’s regulations on erosion and sedimentation control and stormwater management.

Planning Director Michael J. Murphy told the commission at its last meeting Sept. 1, 2010, that the date was being set two months into the future to allow for referrals to other commissions for their opinions. He characterized the changes as technical engineering measures designed to bring the written regulations up to date. The planned regulation changes would be based on state guidelines.

Commission members asked for changes in references to state rules. While the draft town regulations cited state documents with specific dates, commission members asked that the wording specify that town practices be based on the most current state guidelines, rather than being tied to documents bearing a specific date.

Members also raised questions about jurisdiction. In response to their questions, Mr. Murphy noted that normally the Planning Commission would apply the regulations on erosion and sedimentation and stormwater runoff. However, he said he wants to ensure that standards among the land-use agencies are unified. A similar set of changes will be proposed for the Planning Commission. Matthew J. Davis, manager of planning services, said the standards have already been incorporated into the inland wetland regulations.

The proposals included some new definitions such as for Green Roof, Low Impact Development and Best Management Practices, though what role these concepts will play elsewhere in the regulations was, when  mentioned,  noted only in passing.  However, the proposals did include a definition of invasive plants and a list of such plants, along with new language specifying that landscaping with such plants would be prohibited. The rule would not apply to single-family houses on detached lots.

The draft changes did not deal specifically with the Town’s Water Resource Protection District, currently the subject of a special section (6.12) in the Zoning Regulations.

The stormwater regulation changes are separate from an ordinance being drafted by the Director of Public Works to deal with illegal connections to the town’s stormwater system. The Town Council is expected to act on the ordinance in January.

The proposals discussed Sept. 1 are part of an overall update of land-use regulations that has been in the works for about 2 1/2 years. Much of the update remains to be considered by various commissions. Still to be sorted out, among other matters:

–A consulting company’s suggestion that Groton institute a formula-based means of calculating the number of residential units that may be built on a tract of given size and land features. This would replace current regulations based on lot size.

–Extension to 200 feet from 50 to 100 feet of review areas for land-disturbing activity adjoining major streams in the town, accompanied by authority of OPDS to make decisions on “minor” matters affecting wetlands and watercourses.