Experts have predicted that 50% of major cities will be considering desalination to supplement their water supply in the coming decade. The City of Corpus Christi seems to be well on its way to join its fellow Texas cities El Paso and San Antonio that have already developed desalination plants to support their cities especially during times of drought.
Corpus Christi officials have conducted a feasibility study showing the importance that desalination technology can play in the security of the city’s future water supplies. In 2014, the government requested to secure a drought-proof water supply to meet future needs of the Coastal Bend citizens and industries. This would be the first seawater desalination plant in the state.
Corpus Christi’s four major water sources currently include Choke Canyon, Lake Corpus Christi, Lake Texana, and the Colorado River, all of which are surface water sources. Reports in the past few years have shown water supply has decreased due to the new drought of record, greater sedimentation rate than expected in Choke Canyon and callback provisions with Lake Texana water rights. On the other hand, water demand is continuing to rise due to economic growth, industrial use and urbanization. The much needed drought-proof supply of freshwater has reached a trigger point.
These new demands are expected to require a drought-proof supply by 2022 to 2023. They have determined the seawater desalination project to be an adequate solution to meet these needs and financially feasible given this time restriction. They have proposed a 30 million gallon per day (mgd) facility on Inner Harbor and a 40 mgd facility at La Quinta Channel permits. In actuality, these facilities will produce 10 mgd with the ability to expand to 20 mgd in a year or less. Comparatively, Texas’ largest desalination plant and the world’s largest inland desalination plant, El Paso’s Kay Bailey Hutchinson (KBH) plant, can produce up to 27.5 million gallons of freshwater daily.
Assuming the permits can be acquired in a timely fashion, this project will alleviate the city’s dependency on surface water which poses a risk to industry during times of drought.
Due to projections of future increases in demand and recent decreases in supply, a timeframe has been set to complete the project before demand exceeds the trigger point. The committee has determined this as the point when demand exceeds 70% of firm yield which they are now approaching. Known increases in water demand are projected to occur in 2022, 2023 and 2028. The initial increase in 2022 is due to a 25 mgd contract with Gulf Coast Growth Ventures and in 2023 for an additional 5 mgd with Steel Dynamics Southwest, LLC.
Seawater desalination provides a consistent supply of water that can be expanded to meet future drought conditions and industrial demand, as well as being an affordable and timely option. It takes about 24 months to complete a project like this from design to build and start-up. The KBH plant likewise took two years to complete. Given this timeline, they need to start the design and build of the first plant in early 2021 and the second plant should be initiated 24 months prior to the next significant expected increase in demand.
Initial construction cost for the plant at 10 mgd capacity is $140 MM. To increase it to 20 mgd will cost approximately $50 MM. Texas Water Development Board financing from State Water Implementation Fund for Texas (SWIFT) will include a 30 year loan at 2% interest. With the goal of beginning construction in 2021, the application for the SWIFT loan would need to be submitted in February 2020. The city has also enacted a Drought Surcharge Exemption Fee for large volume users at $0.25 per 1000 gallons which is generating revenue at about $3.5 MM per year. In 2022, with increased demands, this revenue will jump to $5.8 MM annually. All customers continue to pay the $0.05 rate as designated by the Raw Water Development Charge. The city also has some available debt services which will be paid off in 2028-2030 timeframe.
Based on these timeline projections, the first desalination plant in the City of Corpus Christi will be operational in early 2023. Alternative sources for water continue to be looked at and this project will not serve as an all-encompassing solution to the water supply issue. Other projects include water reuse, aquifer storage and recovery, and groundwater use. Seawater desalination has been identified as the number one priority due to affordability and proximity to the city.
You can find updates to the project and more information at https://www.cctexas.com/desal and you can join me and our partners at the 98th Meridian Foundation as we continue to fight to ensure the nexus of water, energy and land will remain vital issues to all Texans.