Three miles of bike path starting in Mattapan Square, a revamped Martini Shell for performances, and a new canoe and kayak launch in Hyde Park will be part of a new "Neponset River Esplanade," Gov. Deval Patrick announced last week, approving $5.18 million for the work.

The park will be another step in the state's long-term master plan to build parks and paths along the entire coast of Dorchester and the banks of the Neponset, connecting Boston Harbor to the Blue Hills Reservation in Milton.

"It's a great start to a plan that will need additional funding," said Valerie Burns, director of Boston Natural Areas Network. "Dorchester - with the Pope John Paul II and Granite Avenue parks - has really shown what the opportunity means to neighborhoods, but Mattapan and Hyde Park have been waiting for their sections of the park to begin."

The first work will be cleaning up the Martini Shell in time for an event in late June, said Department of Conservation and Recreation spokesperson Wendy Fox. The heavier work will begin in November and be completed sometime in 2010.

Other gaps in the proposed park system, such as the one between Central Avenue and Mattapan Square, will prove more difficult to build than the esplanade, said Burns. Fox said a portion of the state funding will go toward a land survey of that area, and estimating the cost of getting around each of two 1,000 foot obstacles on both the Boston and Milton sides of the river in order to determine which side would be the most feasible, cost-wise.

On the Boston side, the Riverway Plaza building juts out into the river, and would require a cantilevered platform to hold the bike path. Fox said the building's owners are open to the idea of having the path there, but have questions about how it would be engineered.

On the Milton side is a difficult stretch of land owned by the city of Milton.

Another gap in the greenery is a 14-acre stretch of land in Port Norfolk, which is awaiting the completion of a study detailing just how contaminated the soil there is. Fifteen-year-old plans for a park there include a pine grove, a lookout and a tot lot. Preliminary findings revealed that levels of PCB's at the site were lower than expected at a Port Norfolk Civic Association meeting in January, but the full report isn't expected until sometime this spring.