Groton — Rain gardens at the city's Municipal Building campus, more trees at Washington Park, and a resilience corridor trail along Birch Plain Creek are some of the ideas from a climate resilience plan for the city.

While consultants are finalizing the Community Resilience Plan, they presented an overview during a public workshop on Thursday. The plan will include recommendations and concept designs for which the city could then pursue funding, if it decides to do so.

Noah Slovin, associate resiliency planner at SLR Consulting, said the three central effects of climate change — rising temperatures, changing precipitation patterns and rising sea levels, which can contribute to coastal flooding  — have a wide range of impacts on a community and region. The goal is to understand the specific impacts on the city and how to address them.

The consultants are in the process of developing recommendations based on a risk assessment that considered four types of hazards — flooding, erosion, stormwater runoff and heat — and their potential impacts on socially vulnerable populations, residential and commercial areas, infrastructure, community resources and natural resources. The plan then includes risk ratings for different parts of the city.

For example, the Five Corners area has an overall low risk of flooding and erosion, but a high risk for stormwater runoff and heat, while the Brandegee Avenue neighborhood has a moderate risk for flooding and erosion, low risk for stormwater runoff and a high risk for heat.

Dense buildings, impervious surfaces and a low amount of tree cover can lead to an "urban heat island" effect with particularly high heat levels in certain areas, but ideas, such as urban forests, can help with cooling, Slovin explained.   

The plan objectives outlined by Slovin are to: reduce the impacts of stormwater flooding, mitigate extreme heat impacts on residents, enhance the resilience of local businesses, create a flood-resilient shoreline and a resilient transportation network, increase the resilience of socially vulnerable populations and improve the resilience of municipal assets.

Ideas for resilience 'pilot projects'

Four resilience concepts were presented: installing rain gardens at the Municipal Building campus to reduce runoff, planting shade trees at Washington Park, resiliency improvements on Shore Avenue, and a proposed Birch Plain Creek Trail.

Slovin said the overall plan also will have citywide recommendations, but these are site-specific examples that the city could pursue as "pilot projects."

Cierra Patrick, economic development specialist for the City of Groton, said the concept project combined expertise from SLR and city departments with community ideas, are focused on city-owned land and are examples of short-term projects of one to three years that the city could implement.

The rain gardens proposed at the Municipal Building campus "would capture rain runoff from the surrounding pavement and allow the water to percolate into the ground rather than enter the stormwater management system," according to a description of the concepts.

Several potential "nature-based" concepts "to reduce the risk of flooding along a section of Shore Avenue" were outlined in the description.

"Sea level rise projections show that this area of road will experience minor flooding on a near-daily basis by 2050," according to the description. "By constructing a low berm and regrading a small city-owned park on the shoreline, that water will be prevented from accessing the road. The proposed berm project would include installation of tide gate structures on drainage outfalls to prevent high tide water from flowing backwards through drainage pipes and into the street."

Other potential solutions include "pursuing a living shoreline or nature-based approach to replace the Shore Avenue retaining wall," "planting shade trees in open spaces or along the road itself" and planting trees in spots at Eastern Point Beach Park.

Another concept, planting shade trees in areas of Washington Park, "could serve as a case study for more widespread tree planting efforts in the City," according to the description.

The proposed tree plantings would not only address a slightly elevated heat risk in that area, but also bring the benefits of the trees — including providing shade and reducing stormwater runoff risks — to an easily accessible location in the city, Slovin explained. 

"It’s a place that everyone in the city uses, and it’s fairly easy to get to," Slovin said.

The idea for the Birch Plain Creek Trail, which would "connect and improve existing trail systems at the Birch Plain Creek Open Space area and behind the Municipal Building," would "include educational signage and highlight resilience-related features," such as retention ponds and rain gardens, according to the description.

"The proposed trail would be a constructed path using pervious materials, allowing it to be used by bikers, and bike-share stations would be placed at the two ends," according to the description. 

Slovin explained that the concept designs are the initial phase. If the city moves forward with the ideas, it would need to secure funding for them and then go into the design phase, and then implementation and construction.

During Thursday's workshop, people provided comments and did activities, such as placing stickers on a map of Eastern Point Beach to show where they thought it would be a good idea to place trees. The feedback will be incorporated into the final plan, Slovin said.

Patrick said the current plan is to present the study's findings to the City Council at the May 23 Committee of the Whole meeting.

There also are plans to launch a page on the Greater Groton website to further engage the public on resilience topics and also hold workshops during the spring and summer, she said.

k.drelich@theday.com