NORTHAMPTON — A $100 million fund to support the health and resilience of the Connecticut River watershed, including money that would go toward improving aging flood controls and dikes and upgrading water and sewer systems, is being sought by area officials as part of the coming state environmental bond bill.

“Dedicated funding for specific types of capacity building, inter-municipal cooperation and project implementation is necessary for Connecticut River communities to address climate change impacts, maximize economic positive impact and, most importantly, protect the public safety of our residents,” reads a portion of the three-page letter sent on Tuesday to Rebecca Tepper, secretary of the Executive Office of Energy and Environmental Affairs.

The letter is signed by officials in 16 cities and towns next to or near the river, which extends 67.7 miles through Massachusetts. Signers include Northampton Mayor Gina-Louise Sciarra and Holyoke Mayor Joshua Garcia, as well as representatives from Amherst, Hadley, Hatfield, Deerfield and Whately.

Among the 13 members of the western Massachusetts legislative delegation signing the letter are Sen. Jo Comerford, D-Northampton, Sen. Jake Oliveira, D-Ludlow, Sen. John Velis, D-Westfield, Rep. Natalie Blais, D-Deerfield, Rep. Dan Carey, D-Easthampton, Rep. Mindy Domb, D-Amherst, Rep. Patricia Duffy, D-Holyoke and Rep. Lindsay Sabadosa, D-Northampton.

Both executive directors of the regional planning agencies, Linda Dunlavy at the Franklin Regional Council of Governments in Greenfield and Kimberly H. Robinson at the Pioneer Valley Planning Commission in Springfield, also signed onto the communication to the Healey-Driscoll administration.

Dunlavy in a statement said that the watershed and its tributaries, including the Deerfield, Millers, Fort, Westfield and Chicopee rivers, are central to the region’s past, present and future economy, land use and character, which are all at risk from increased precipitation and storm events due to climate change.

“Creating a program with focus on and funding for watershed resiliency allows us to use science, data and community engagement to work together and with our neighbors upstream and downstream to strengthen and protect our regions,” Dunlavy said.

Robinson made similar comments, calling the Connecticut River “the backbone of our region.”

“A dedicated fund for the Connecticut River Watershed would empower our towns to work together in addressing these urgent challenges, enhancing flood resilience and protecting our farmland, homes and natural resources,” Robinson said.

The advocates for the fund note that it would go beyond existing grant programs that have limited cycles and are challenging for municipalities to access, and also don’t encourage partnerships between communities.

The request is also for regional equity, asking for “equitable access to state support through a fund that could be deployed to address a range of necessary advances including repairs and upgrades to existing flood control and water/sewer systems; new infrastructure; and research, planning and project management support.”

Already, the state is investing in coastal measures, the letter notes: “We applaud the state’s climate preparedness and support as it relates to coastal communities and are aware of the various resources and initiatives available in eastern Massachusetts.”

The Connecticut River is one of 14 American Heritage Rivers and the nation’s first and only National Blueway.

In addition to being a lifeblood for farms, the letter cites other purposes the river is used for, including its past in supporting mills.

“The river and its tributaries have driven and continue to drive regional and statewide economic development in the form of power use and generation, travel, tourism and outdoor recreation,” the letter reads. “The river’s history of powering mills that are now mostly closed leaves the region with brownfield sites and large abandoned structures in our downtowns.”

Scott Merzbach can be reached at smerzbach@gazettenet.com.