Has the San Diego County Water Authority physical plant reached the point of diminishing returns?
| Aging Water Reservoir Infrastructure in San Diego County - Key reservoirs over 100 years old |
As significant delivery lines are nearing the end of their service life across San Diego, mains are breaking at a pace of more than 100 a year, according to an analysis of city data by inewsource, a journalism non-profit based at San Diego State University. Those breaks plus tens of thousands of leaks have sent an estimated 360 million gallons of water rushing or seeping into streets, homes and businesses since 2004.
And it’s not just water that’s been lost.
San Diego has paid out at least $10 million to settle claims and pay contractors for repairs to private property that was damaged by water main breaks during the past eight years. More than $350,000 of that was to house people forced from their homes by the breaks.
San Diego's Water System
The San Diego County Water Authority (SDCWA) is a public agency responsible for managing and providing a reliable supply of water to San Diego County, California. It was formed in 1944 and is governed by a board of directors representing its member agencies, which include cities, water districts, and municipalities in the San Diego region.
Key responsibilities and functions of the San Diego County Water Authority include:
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Water Supply Management: SDCWA is tasked with securing and managing a diversified and reliable water supply for the region. This involves sourcing water from various local and imported sources, including the Colorado River and the California State Water Project, as well as promoting water conservation and efficiency.
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Infrastructure Development: The authority invests in and maintains infrastructure such as pipelines, reservoirs, and treatment facilities to store and distribute water to its member agencies and customers.
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Regional Coordination: SDCWA works collaboratively with its member agencies and other stakeholders to ensure the efficient and equitable distribution of water resources in San Diego County. This often involves negotiating water supply agreements and resolving water-related issues.
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Water Conservation and Education: The authority promotes water conservation efforts through public outreach and education programs. This is especially important in drought-prone California, where water conservation is crucial for sustainable water management.
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Emergency Preparedness: SDCWA plays a role in planning and preparing for water-related emergencies, such as droughts, wildfires, and other natural disasters, to ensure the region's water supply remains resilient.
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Environmental Stewardship: The authority is committed to protecting and enhancing the region's natural environment and ecosystems through responsible water management practices.
The San Diego County Water Authority plays a vital role in ensuring that San Diego County residents have access to a reliable and safe water supply, particularly in the face of challenges such as drought and climate change. It works in close partnership with its member agencies, the Metropolitan Water District of Southern California, and other entities to achieve its mission of water supply reliability and sustainability.
The cost of water in San Diego has blown past L.A., according to a new report
San Diego is at the end of the pipeline when it comes to importing water from the Colorado River and the Sacramento Bay Delta. So it’s no surprise its costs have exceeded those of Los Angeles and other parts of Southern California.
However, a recent report from a leading expert finds there’s more behind the skyrocketing price of water in the San Diego region, which over the last decade has seen wholesale rates increasingly outpace neighbors to the north.
Plummeting demand coupled with a bevy of costly projects — from raising dams to a desalination plant in Carlsbad — created a perfect storm that sent water rates soaring over the last decade, according to a recent analysis by longtime environmental economist Michael Hanemann of Arizona State University.
The San Diego County Water Authority has agreed to buy at least 48,000 acre-feet of water from the plant each year for about $2,000 an acre-foot. An acre-foot equals about 326,000 gallons, roughly enough for two families of four for a year. The authority has made a long-term bet that those costs — now double those of the most readily available alternative — will eventually be competitive. But it still means the authority will pay more than $3 billion over 30 years for only about 7 percent of the county’s water needs.
As Sandra Kerl, the deputy general manager of the authority, said in a recent interview, “There’s a lot of eyes on this.”
The technology used in the Carlsbad plant, known as reverse osmosis, was developed decades ago. It involves pushing the water through a series of microscopic sieves rolled up into larger cylindrical filters. The energy-intensive process separates pure water from both salt molecules and impurities. The filters, some of which are made locally, are cheaper and more durable than they were a decade ago, industry accounts say, bringing down the overall price of the plant and its operations.
This is signicantly more than SDCWA charges it member agency distributors:
In 2023, the Water Authority will charge its 24 member agencies the equivalent to an all-in rate of $1,579 per acre-foot for untreated water, or $56 more per acre-foot than they currently pay. Charges would be $1,929 per acre-foot for treated water, or $96 more per acre-foot than in 2022
The SDCWA may have missed a chance to finance significant infrastructure upgrade at the low interest rates prevalent until recently.
California Leaking: People, Pipes, and Prices
The governor and other policy makers continue to overlook a substantial source of additional, largely accessible water buried, literally, under Californians’ feet: water pipe leaks. Authorities overseeing California’s 8,000 water systems are fully aware that a consequential amount of the water entering their systems never reaches consumers’ faucets. Why? California’s distribution systems, consisting of hundreds of thousands of miles of aging pipelines, are full of known leaks that are going unrepaired, mainly because water prices are so low that the revenue from water recovered from fixing them won’t cover the immediate repair or replacement costs.
California water utilities distribute more than 1.2 trillion gallons of water a year to residents (equal to about a fifth of agricultural use), according to government data.5 At least 7 percent of residential accessed water—or at least 84 billion gallons—is lost to known leaks.6 This water volume could, if recovered through repairs, flood more than 191,000 football fields one foot deep—which is enough to meet state government’s targeted annual per person water use of at least 4 million Californians (a tenth of the state’s population). While the critical age and reliability of water pipes varies greatly by water district (as does the rate the consumer is charged), we stress the state’s consolidated estimate of water loss due to leaks is thought to be conservative by some industry insiders. Meaning, we believe there is a high degree of probability that focusing on the economics of water infrastructure repair and replacement could have a consequential offsetting impact to droughts and the need for water police.
We’ve emphasized “at least” because many leaks in the state’s hundreds of thousands of miles of water pipes, if detected, go unreported and others remain undetected but are identifiable with the use of above-ground detection technology. Many water authorities have resisted adopting this technology because leak detection costs (conservatively) about $600 per mile of evaluated pipe, according to the California Water Resources Control Board. To deploy the technology, water authorities must expect the recovered water to generate more revenue than the cost of the repairs or replacement of aging pipes.
Water districts may also be reluctant to find leaks because California law requires districts to report leaks they find and then repair those with water losses greater than “acceptable” loss levels—which means leaks discovered can be budget-busting with below-full-cost water prices. According to the state’s Water Board, the repair cost for service lines averages about $2,300. For a water main break, nearly $6,000—a conservative estimate according to some industry insiders. Of course, the sky is the limit for major breaks, the likes of which are expected to occur progressively as the water system replacement needs go unaddressed.
| Cast iron pipes – Used the late 19th and early 20th centuries | 120 years |
| Iron pipes – in the 1920s and thinner than cast iron pipes | 100 years |
| Ductile iron pipes - In use beginning in the 1950s | 100 years |
| Polyvinyl Chloride (PVC) - Popular in the 1970s | 70 years |
| High-density Polyethylene – Popular since 1990s | 70 years |
A water treatment plant has a life span between 25 and 50 years - U.S. Environmental Protection Agency
Sources: American Water Works Association, U.S. Environmental Protection Agency, American Water Works Service Company
A leaky ship
While not nearly as bad as older cities in the east and midwest which have some pipes going back 300 years, San Diego, since its rapid growth in the first half of the 20th century is faced with a rapidly aging water infrastructure. According to the San Diego County Water Authority, there were 1,456 water main leaks in 2020, resulting in a loss of 145,678,901 gallons of water. This is equivalent to the daily water consumption of over 12,000 people. The table below shows some performance metrics over the last 17 years obtained from the same source. Percent loss was taken by dividing the water loss by the water delivered to customers. Another metric is number of leaks per mile, which seems to be increasing fairly steadily.
I looked through the San Diego County Water Authority’s (SDCWA) annual water quality reports for the period 2003 through 2020 and couldn’t find any data on the number of customer days of service lost due to system repairs. The value of this loss, particularly for commercial customers should be included in planning investment for line replacement and deploying systems to detect and locate leaks more rapidly. I also looked through the SDCWA’s website and couldn’t find any data on this metric. The SDCWA may track this metric internally, but it does not appear to be publicly available. I apologize for not being able to provide you with this information.
| Leaks per Mile | Pct Loss | ||
| 0.48 | 5.87% | ||
| 0.53 | 6.42% | ||
| 0.59 | 6.77% | ||
| 0.64 | 7.10% | ||
| 0.69 | 7.42% | ||
| 0.74 | 7.70% | ||
| 0.79 | 7.98% | ||
| 0.83 | 8.23% | ||
| 0.88 | 8.44% | ||
| 0.92 | 8.67% | ||
| 0.97 | 8.88% | ||
| 1.01 | 9.09% | ||
| 1.05 | 9.28% | ||
| 1.10 | 9.45% | ||
| 1.14 | 9.61% | ||
| 0.58 | 7.20% | ||
| 0.63 | 7.71% | ||
| 0.68 | 8.01% |
As you can see, the percentage of water lost to leakage has been increasing steadily over the past two decades despite a drop in 2017. This is a concern, as it means that more and more water is being wasted. This is not a favorable trend. This is typical of excess defered maintenance on a plant which has reached end of life. The San Diego County Water Authority is working to reduce water loss from leaks through a variety of measures, including:
In 2019, San Diego had the fewest water main breaks in 15 years. The 38 breaks last year was a drop of more than 35 percent from 2018 and far lower than the record 131 breaks recorded in 2010. The number of sewer spills dropped nearly 25 percent last year, from 50 in 2018 to 38 in 2019. Both totals are far lower than the record 365 spills recorded in 2000.
"New pipelines, monitoring tools and the vigilance of our Public Utilities crews are making a huge difference," said Shauna Lorance, who took over as the city's Public Utilities director August 2019 until February 2022 when Juan Gerreiro took over. City officials credited the decreases to ramped-up maintenance and replacement efforts on water mains, sewer lines and pipes, particularly those made of cast iron.The Economics of Water-Pipe Leak Repairs Many leaks go undetected until pipes break and become above-ground geysers that often cause substantial economic damage. In November 2021, a San Diego Uber driver and his passenger were injured by a water geyser from a major pipe failure that took days to repair, causing a shutdown of a section of Interstate 5, resulting in a commuter nightmare, lost earnings for local businesses, and property damage for many residents in the area. The July 2022 break in a twelve-inch water main in the middle of the night in the Hollywood Hills area of Los Angeles caused the shutdown of a major freeway and flooded major streets deep enough to require rescues of drivers from the tops of their cars, as captured on LA nightly news video.7 The repair costs will likely be enormous. The problem of water pipe breaks and leaks will only worsen in coming years as water pipes continue to age. Two-thirds of LA’s water pipes were installed before 1950 and will reach the end of their useful life this decade. The water main that broke in July in LA’s Hollywood Hills was 91 years old, with many miles of water mains installed more than a century ago. Water officials agree that repairs will cost billions, which cannot be covered without water-price increases. Again, this means that leak repairs and water recovered depend
directly on water prices: The higher the water prices, the more leaks
can be detected and repaired—and the greater the potential recovered
water. Yet, California water price increases have been checked by
Proposition 218, passed in 1996 to "cost of service". Water Rates Under Prop. 218The September 1997 issue of Debt Line reported on an Attorney General opinion which concluded that water service was not “property related” for purposes of Article XIIID of the California Constitution (Proposition 218). Such an interpretation, if adopted by the courts, would permit local governments to impose water rates in a manner that deviates from the important “costs of service” requirements mandated by the new law, as well as depriving California taxpayers of significant procedural protections. It is the drafters’ position, supported by the clear language of
Proposition 218, the liberal construction provision, and the intent of
the voters that fees and charges for water service are governed by
Proposition 218. To the extent tiered water rates are imposed in a
manner that deviates from “cost of service” requirements, those rates
are in violation of Proposition 218. Local governments or special
districts which do not abide by the requirements of the new
constitutional language do so at the risk of litigation. Pay me now or Pay me later - Costly Water Main BreakIn almost all cases, the City of San Diego will be responsible for a water main break in San Diego. That’s because the City of San Diego owns the water conveyance infrastructure of which the water main is a part. It’s the City’s property so the City is responsible, not the SDCWA. The key is determining who owns the water main break. Sometimes, that may be the City of San Diego County, the County of San Diego, or some other city. Whoever owns the water conveyance infrastructure is the responsible party. Most property insurance will not cover such damage, because flood is not covered. Inverse condemnation is a constitutional right that makes the government pay for damage they caused. The city of San Diego paid more than $181,000 in April 2020 to settle five more legal claims stemming from a 2018 water main break that flooded several North Park properties. The Oct. 4, 2018, water main break on Idaho Street has already cost the city more than $241,000 in settlements, bringing the total of payouts to nearly $423,000, data obtained by NBC 7 Investigates shows. In the claims, North Park residents said their properties were severely damaged when a 24-inch transmission water main burst on Idaho Street, sending hundreds of gallons of water into homes, cars and a community park. The main break caused a gaping sinkhole on Idaho Street in the morning commute hours. Residents awoke to find inches of water flooding outside, and in some cases, into their homes. Cars sat in pools of water as the water main gushed for hours. The majority of last month's payouts went to one pair who claimed their property suffered hundreds of thousands of dollars in damage from the Oct. 4 main break. The legal claim settlements were just the latest payouts the city has made over water main breaks. Since January 2018 the city of San Diego has paid $2.35 million in damages from broken water mains. The value of water lost in leaks in
2020 was approximately $900,000, not including cost of leak repair and
court damages later awarded to customers and those damaged by the leak.
For example the millions lost by La Jolla homeowners when a watermain leak destabilized a hillside. Miles of aging water lines remain under San DiegoSince 2013, the city has been working to replace about 180 miles of
cast-iron pipes with much more reliable PVC piping. In that time, water
main breaks have dropped from a peak of 131 in 2010 to 33 in 2020. [Note that PVC pipe has a rated life of 75 years, compared to CI with 120 years] A city spokesman said Tuesday that by 2025, the last 25 miles of cast-iron would be replaced. But that won't solve the threat completely. Most of the city's pipelines are concrete. And while they're more reliable than cast iron, they do fail, such as the case in Balboa Park. The city spokesman said, however, that they are checked on a regular basis. Maybe a systems engineering approach could help. | |||
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Cost of Main Breaks, Water Loss add up for City |
A three-month examination by inewsource of water main breaks, their locations and costs and the city’s practices found some streets, mostly in older neighborhoods, have suffered more than half a dozen water main breaks in the past eight years. The city auditor, in a report September 2014, said the city does not have a precise accounting of the condition of its water pipes, and because inspecting lines is so expensive “it is generally considered to be more cost-effective to simply fix lines when they break.”
Roger Bailey, the city’s public utilities director, defends the water department’s record, given the vast delivery grid.
Recycle Water
The Pure Water San Diego program recycles the wastewater leaving homes and business The wastewater are treated in steps including ozonation, where ozone gas destroys disease-causing microorganisms; biological activated carbon filtration, where the water is filtered through coal and crushed sand; membrane filtration, in which micro-porous separating layers filters the finest particles before the water goes through reverse osmosis and UV/Advanced Oxidation. Currently, about 85% of San Diego’s water supply came from the Colorado River and Northern California Bay Delta. The rest comes from local runoff and rainwater. The Pure Water project aims to turn enough wastewater into drinking water to supply one third of the city’s needs by 2035.
California is looking to boost water supply and considering new regulations to recycling wastewater straight to your tap. Pure Water San Diego is the City of San Diego's phased, multi-year program that will provide nearly half of San Diego's water supply locally by the end of 2035.
The Pure Water San Diego Program will use proven water purification technology to clean recycled water to produce safe, high-quality drinking water. The Program offers a cost-effective investment for San Diego's water needs and will provide a reliable, sustainable water supply.
San Diego's Pure Water project is in phase one of construction and will supply nearly half of the city's drinking water by the end of 2035. The water goes through a rigorous recycling process. Our crews got to see it all happen at the Pure Water demonstration site.
The Pure Water San Diego program will cost $1.5 billion for planning, design, and construction of Phase 1. Phase 1 is expected to be completed in 2024 and will produce 30 million gallons of purified water per day.
The annual operating costs of the Pure Water program are estimated to be $30 million. This includes the cost of chemicals, energy, and maintenance.
Systems engineering and water resources management: A closer relationship is needed
The relationship between systems engineering and water resources management. The key points are:
- Systems engineering has traditionally been applied in military, aerospace, and industrial fields, but there is interest in using it for civil systems like water resources. However, so far only systems analysis tools are being applied, not the full systems engineering methodology.
- Water resources management has developed its own framework called Integrated Water Resources Management (IWRM) which includes some systems analysis tools but is still evolving after decades of use.
- Water resources systems exhibit complexities like ill-defined boundaries, environmental impacts, long lifecycles, and social/political involvement. This makes them challenging for systems engineering methods.
- Examples are given of different water systems like a reservoir, aquifer, and urban water supply. The urban system seems most amenable to systems engineering due to clearer boundaries and management control.
- Barriers exist between the systems engineering and water resources communities such as separate journals and conferences. Collaboration could benefit both fields. Systems engineering may be able to improve planning methods for water systems.
- Research is needed on how systems engineering models and diagrams could be applied to existing water systems. Case studies of recurring problem archetypes could demonstrate the use of systems engineering for water resources.
In summary, the potential exists to apply more systems engineering methodology to water resources management, but barriers between disciplines must be overcome. Research and collaboration to demonstrate systems engineering's value for water systems planning and design would be beneficial.
Integrated Water Resources Management (IWRM)
Integrated Water Resources Management (IWRM) is a framework developed specifically for managing water resources that involves coordinating across sectors and stakeholders.
According to Grigg (2016):
"IWRM is defined as a process that promotes the coordinated development and management of water, land, and related resources in order to maximize economic and social welfare in an equitable manner without compromising the sustainability of vital ecosystems." (p. 3)
Some key characteristics of IWRM include:
- Considering the whole water cycle and interactions between different parts (surface water, groundwater, water quality, etc.)
- Involving multiple sectors that use/impact water (agriculture, industry, domestic, etc.)
- Coordinating across different levels from local to national
- Using a range of management tools including systems analysis
- Emphasizing stakeholder participation
- aiming for economic efficiency, social equity, and environmental sustainability
Despite decades of development, IWRM remains challenging to implement due to the inherent complexity of water resource systems. It continues to evolve as both a concept and practical framework.
Reference:
Grigg, N.S. (2016). Integrated Water Resources Management: An Interdisciplinary Approach. Palgrave Macmillan.
The San Diego IRWM Program began in 2005 as an interdisciplinary effort by water retailers, wastewater agencies, stormwater and flood managers, watershed groups, the business community, tribes, agriculture, and non-profit stakeholders to improve water resources planning in the San Diego IRWM Region. The program has achieved remarkable success! In 2007, San Diego published its first IRWM Plan and received $25 million from DWR to support 18 high-priority water management projects. In 2011, San Diego obtained another $8 million to support 11 more important projects and $1 million to fund a comprehensive update of the 2007 IRWM Plan. In 2013 and 2014, respectively, $10 million was awarded to support an additional 7 high-priority projects, and $15.1 million awarded for drought relief projects. The region was awarded almost $31 million for 13 high priority projects in 2015. The region received $5.5 million for Disadvantaged Communities Involvement planning projects and $15.3 million in 2020 for 7 priority implementation projects. In 2022, the Funding Area received $5 million for 4 drought projects in underrepresented community areas and $16 million for 6 priority implementation projects. In total, the Region has received approximately $132 million, which has funded 84 priority projects including the 2013 and 2019 IRWM Plan updates.
Applying Systems Engineering
Applying the full systems engineering approach could significantly improve management of a large, complex metropolitan water system with aging infrastructure, in several ways:
Requirements Analysis
- Conduct detailed analysis of current and future water supply needs and quality standards
- Identify requirements for system reliability, redundancy, sustainability, etc.
- Involve stakeholders like government, utilities, businesses and citizens to understand requirements
- Develop key performance parameters to specify and track so all stakeholders are satisfied.
- Given the criticality and vulnerability of the water system to natural and hostile events, require contingency planning.
System Architecture
- Map out the overall physical system components and their interconnections
- Model flows, interdependencies, and controls throughout the system
- Identify integration issues and optimization opportunities
Alternatives Analysis
- Develop alternative solutions to high priority problems like leakages, obsolete parts
- Evaluate alternatives using criteria like cost, performance, sustainability
- Recommend optimal upgrades and improvements
Implementation Planning
- Create integrated plans for priorities like pipe replacement, technology upgrades
- Develop optimized project sequencing and coordination
- Define procurement processes, budgets, roles and responsibilities
Lifecycle Management
- Establish asset management database and condition monitoring
- Implement reliability-centered maintenance programs
- Plan for eventual retirement/replacement of system components
Verification & Validation
- Use system monitoring, analytics and operational testing
- Ensure requirements are met throughout lifecycle
- Update models and plans based on performance data
By taking this more holistic, lifecycle view, systems engineering could help transform management of complex metropolitan water systems to be more proactive, efficient and sustainable over the long term.
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