CIP under Pressure: Rethinking Solutions to the CAVSARP System’s High Head without Breaking the Bank

The Central Avra Valley Storage and Recovery Project (CAVSARP) was designed to recharge and recover Central Arizona Project (CAP) water in response to water quality issues in Tucson and is supplied by 60-in. welded steel pipe (WSP) and a 54-in. high-density polyurethane (HDPE) pipe. As a pressure system, the head characteristics have been a challenge, since CAVSARP was commissioned. There is a large elevation difference upstream to downstream, so control valve cavitation is a concern at the upstream turnouts with downstream turnouts experiencing low head issues. In 2019, the HDPE transmission main suffered a pipe failure, a 100-ft longitudinal crack. Though pipe replacement was recommended, replacing the flow control valves with plug valves was determined to be a viable alternative. After evaluation of several valves, a 20-in. eccentric plug valve proved to be a suitable solution for CAVSARP’s conditions and saved the utility’s CIP budget $18 million by avoiding pipe replacement.