The Railway Commission then wanted the San Diego Flume redone in concrete. Fletcher proposed that the flume be redone in a roofing material. The roofing material was approved and it cost $45,000. The material kept the flume running for another 20 years and the efficiency of the flume, helping to greatly increase profits from 1915 to 1923.
After the relining of the flume the CWC built two reservoirs near the downstream terminus of the flume. One was the Grossmont Reservoir which was built in 1913 with a capacity of 30 million gallons, and the other was the Murray Dam which replaced the La Mesa Dam.
In 1914, the CWC began to sell water to the city of San Diego. This led to the irrigators filing a complaint that they were getting poor water supply because the CWC was diverting water to the city. The CWC had a dual structure rate which determined how much the customers would pay by their land size. In 1917 the Railway Commission made the CWC disband the dual rate structure because of complaints by the customers and irrigators.
In 1920, in a case that was upheld by both the Railway Commission and the US Supreme Court prices were raised. Increased sales to the city interested the CWC because they purchased by the amount of water used and not by the land size.
Eventually, after several attempts, Ed Fletcher successfully sold the Cuyamaca Water Company to the La Mesa, Lemon Grove and Spring Valley Irrigation District for $1.4 million on January 4, 1926.