From Natick it runs east through Wellesley and Needham to the Charles River, which it crosses on the Echo Bridge into Newton.

The aqueduct was initially designed to carry 80 million gallons of water per day, limited by the Rosemary Brook Siphon.

An additional barrel was later added to the Rosemary Brook Siphon increasing the design capacity to 110 mgd.

The main conduit from Farm Pond to Chestnut Hill Reservoir is inclined one foot per mile.

At a number of places on the aqueduct small buildings were built to house control equipment of various sorts.

There are also control houses on either end of the Rosemary Brook siphon in Wellesley, where the water is sent through cast iron pipes to traverse an extended low spot on the route.

Located in Wellesley near the Elm Bank Reservation, this nine-arch bridge carries the aqueduct across a valley containing Waban Brook near its mouth at the Charles River.