When the Portland Water District acquired the Portland Water Company in 1908 they were concerned with the water supply to to the communities they served. To address this concern, The Portland Water District decided to build a new transmission line connecting Sebago Lake to Portland, to be used in conjunction with the existing mains and reservoirs, to increase the amount and pressure of the water being delivered to its customers.

In this photograph, a pipe laying machine is putting a 42 inch cast iron pipe into place; the transmission line was completed in 1912.