The Planning Board has approved changes to the subdivision regulations that specify clearly the requirements for drainage facilities, in an effort to help prevent future flooding.

The changes solidify the responsibility of developers to make sure their drainage facilities are in keeping with the town’s specifications. It also includes language that clearly states developers must re-submit their site plans if any part of the amendment is not being complied.

After severe flooding the past couple of years, the town wants to be more concrete about what they want to see in terms of flood prevention measures.

“The changes that were just made were an amendment to existing subdivision regulations to tighten up some controls from an engineering standpoint to that when the town engineer reviews the plans, it is more clear that these procedures have to be followed,” said Planning Coordinator Nic Strong, adding that many of these practices included in the amendment are already being implemented.

The amendment requires that all drainage facilities are built for a 10-year flood rather than a 2-year flood.

The language added to the subdivision regulations encourages practices such as designing road-crossing culverts to specifications for a 50-year storm; improving run-off slowing systems; and placing drains under the ground at every 300 feet and requiring that such drains lead into a culvert.

The Planning Board voted unanimously to adopt the amendments on May 27 after several meetings spent discussing the changes and a public hearing during their meeting on May 13.

If any changes are made to a site plan after it has already been approved, Strong said, the Planning Board has the authority to ask the developer to submit revised plans for review and approval.

One piece of the amendment spells out plainly that the Planning Board can ask for new plans if the approved ones are not being held to.

One example of that is when developers end up cutting down significantly more trees than they originally planned to cut, which would allow more storm water to run off the site and onto neighboring ones.

“We don’t want to be in a position that more water could leave the site,” Strong said.

Before that language was there, the Planning Board could require a developer to submit plans again, but the amendment just firmly states it.

“Because we had all that flooding over the past three years, we wanted to start being more clear,” Strong said.