Last week crews lined the final segment of unlined canal in our 131-mile canal system, completing an effort that began in the 1950s.
The 1,000-foot section of the Grand Canal, which runs behind the Pueblo Grande Museum near 44th and Washington streets, had remained unlined because of its historical significance.
Even though the canal isn’t prehistoric, it sits near a prehistoric settlement and flows in an area called the Park of Four Waters. This area marks the connection between remnants of Hohokam canals, which were likely constructed between A.D. 750 and A.D. 900 AD; the Valley’s first modern canal, Swilling’s Ditch, built in 1867; and the Grand Canal.
SRP worked with the City of Phoenix — which is constructing a multiuse path in the area — to reach an agreement with Pueblo Grande to allow it to be lined.
Jim Duncan with SRP’s Water Engineering and Transmission group, said that Pueblo Grande wanted to preserve the look and feel of an old dirt canal as much as possible, so crews used dirt-colored shotcrete — a mixture of cement, sand
Lining the canal will better protect it from erosion while helping to control seepage losses, increase canal capacity and reduce maintenance.
“The canal will be protected; artifacts under it or deep in the banks are well-preserved; and it still has a natural look,” Duncan added.
To protect the sensitive nature status of the site, Hassan Elsaad with SRP’s Water Engineering group, developed a modified approach to lining the canal. Instead of disturbing the earth, which contains archaeological artifacts, crews hand-drilled holes into the edge of the existing concrete bottom and used steel rebar and wire to connect the shotcrete from the bank to the floor.