City of Morro Bay, California, USA – Planned groundwater augmentation

The City of Morro Bay is located on the Central Coast of California in San Luis Obispo County. Incorporated in 1964, the City provides its roughly 11,000 residents with water, sewer, storm drainage and other essential services. The City’s Water Reclamation Facility recycled water project will improve water supply reliability and resiliency for the community of Morro Bay.

The City currently has two primary sources of water: 1) treated water from the State Water Project (State water); 2) groundwater from the Lower Morro Valley Groundwater Basin (Morro Basin). State water is the City’s primary supply and the City currently has the ability to receive a maximum of 1.1 million gallons (4.4 million litres) of State Water per day. During periods where State water is unavailable, due to droughts, maintenance, and/or unplanned shutdowns, the City pumps Morro Basin groundwater to meet its water system customer demand. The City can extract up to 0.5 million gallons (1.9 million litres) per day from the Morro Basin.

Due to concerns with the previous wastewater treatment plant being located in the floodplain, tsunami inundation zone and vulnerable to sea level rise, the City recently built a new wastewater treatment facility. The facility includes an advanced treatment system, which incorporates reverse osmosis and ultraviolet/advanced oxidation processes, to produce advanced purified recycled water for drinking purposes (potable reuse). The advanced purified recycled water produced at the Water Resources Center is intended for use in the City’s indirect potable reuse program, which includes injection of advanced purified water into the Morro Basin and extraction through the City’s existing Morro Basin wells. Injection of advanced purified water into the Morro Basin will enhance recharge, prevent seawater intrusion, improve water quality and improve the overall reliability and resiliency of the City’s water system.

While the treatment facilities have been completed, the City is in the process of designing the injection wells, well equipping, and conveyance facilities. It is estimated that at full build-out the City’s indirect potable reuse program could have the capacity to treat and inject up to 0.7 million gallons (2.9 million litres) per day of advanced purified recycled water into the Morro Basin. The injection well facilities are currently anticipated to come online in the third quarter of 2026.

For additional information and/or to schedule a tour of the City’s Water Resources Center please visit: https://morrobaywrf.com/