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Alexander Schultz, Otay Water District geographic information systems technician, operates a drone in front of a district water storage tank. Photo: Otay Water District

Drones Offer Water Agencies Cost, Safety Benefits

Water agencies across San Diego County are saving time and money while improving employee safety with drones.

Industry analysts say drone use by water agencies worldwide is growing. The Helix Water District, Otay Water District and the San Diego County Water Authority have embraced the technology, using drones to inspect and monitor facilities, and to map and survey inaccessible areas.

Helix used a drone in February to check rooftop air vents on a water storage tank in El Cajon, rather than send employees high in the sky to do it. The agency determined it was too risky for employees – even with safety equipment – and too costly to have staff inspect the vents outside the 120-foot-high Fletcher Hills Combined Tank.

“We continually look for ways to utilize technologies where appropriate to minimize facility down time and to keep staff safe,” said Carlos Lugo, general manager at Helix. “Drone technology is proving to be a useful and cost-efficient way to survey and keep the district’s facilities properly maintained.”

Drones provide a safe and cost-effective alternative for inspecting the condition of storage tank vents without placing employees at risk or taking the storage tank offline. Photo: Helix Water District

Drones provide a safe and cost-effective alternative for inspecting the condition of storage tank vents without placing employees at risk or taking the storage tank offline. Photo: Helix Water District

Helix uses drones to inspect interior roof supports of its water storage tanks. The supports are especially vulnerable to corrosion because they are constantly exposed to humidity and heat.

Drone image of a roof bracket inspection. Photo: Helix Water District

Drone image of a roof bracket inspection. Photo: Helix Water District

Inspecting the storage tank roof supports requires moving 30-foot-high scaffolding from one support to the next, a time-consuming and labor-intensive process. To cut down that time, Helix used a drone to get high-resolution images of the supports. The drone images showed which ones needed repair without moving the scaffolding to each support.

A drone helps reduce the need to move scaffolding to each bracket during inspections. Photo: Helix Water District

A drone helps reduce the need to move scaffolding to each bracket during inspections. Photo: Helix Water District

“Using drones for this type of inspection work is a simple, elegant and safe solution,” said Jim Tomasulo, Helix’s director of engineering. “We anticipate using drones for this and other purposes.”

Drone inspections of reservoirs, treatment plant

The Otay Water District also is finding drones useful to save money and improve employee safety.

After a two-year study and evaluation period, the district is now using two camera-equipped drones to assist with preliminary inspections of its water facilities in eastern and southern San Diego County, including 40 potable water reservoirs, four recycled water reservoirs, 20 pump stations and a recycled water treatment plant.

Drones Reduce Risk

Countywide, the Water Authority uses drones to monitor rights of way and to survey inaccessible landscapes.

When a drone was used to get images and video of steep terrain on the Second Aqueduct west of Interstate 15 and south of the San Luis Rey River, the images were 10 times higher resolution than stock aerial images. Using the drone also kept staff from being exposed to potentially dangerous conditions.

The Water Authority is also exploring using drones for future surveys and potentially at water transportation, treatment, and storage facilities, where cutting-edge technology is used to save ratepayers money.

Drones are helping the Water Authority monitor rights of way, particularly in areas of rugged terrain.

But the potential of drone use is not limited to visual photography of elevated water tanks and surveying remote areas.  Water quality monitoring is another potential application.

Water agencies can use drones with infrared cameras “to monitor water areas remotely at higher spatial resolution than ever before, at low cost and at any time,” Michal Mazur, with Drone Powered Solutions, told Waterworld.com in a recent article about the advances in drone use.

A $28.6 million project to rehabilitate more than four miles of large-diameter pipeline between Lake Murray and Sweetwater Reservoir was completed in June 2018. Photo: Water Authority

Water Authority Adapts to Overheated U.S. Construction Costs

Construction costs have surged across the nation over the past year as prices for materials used in construction have risen. At the same time, contractors are struggling to meet project deadlines due to a shortage of skilled workers, construction trade industry publication Constructive Dive reported on March 18.

Those higher construction costs are impacting local agencies, including the San Diego County Water Authority. Agency staff briefed the Board of Directors’ Engineering and Operations Committee in mid-March on how those market changes are driving up costs of infrastructure and maintenance projects.

“The Water Authority will monitor market trends and adjust individual project budgets as required,” said Gary Bousquet, the Water Authority’s deputy director of engineering. “Our planning process includes prioritizing projects, and evaluating the timing or need and scope of projects. We will adjust our project cost estimates to meet changing market conditions.”

Labor shortage adds to increasing costs

A labor shortage in the construction industry is one of several factors increasing costs.

“While construction hiring remained very widespread through January [2019], industry employment gains nationally slowed in February—possibly an indication that the pool of qualified workers has dried up in many markets,” Ken Simonson, chief economist with the Associated General Contractors of America, said in a new report.

The report showed that construction employment declined by 1,300 jobs in the San Diego region from January 2018 to January 2019.

“There are many large-scale construction projects underway in Southern California, while at the same time, there is a shortage of skilled and unskilled labor, which means greater competition for those workers,” said Brent Fountain, a principal engineer with the Water Authority. “In addition, increasing prices for materials are impacting the costs for both maintenance and capital projects.”

Water Authority project bids from contractors in 2018 ranged from $200,000 to $6 million over the project costs estimated by the Water Authority, according to Fountain.

Contractors bid above estimates in 2018

: In 2018, the Water Authority received 2-to-5 bids for projects, and the bids were all well-above agency estimates. Graphic: Water Authority

In 2018, the Water Authority received 2-to-5 bids for projects, and the bids were all well-above agency estimates. Graphic: Water Authority

“We’ve received fewer bids at higher bid amounts from contractors for several projects in the past eight months,” he said. “The Water Authority generally had more bids and bid amounts closer to our project cost estimates, from 2014 through 2017.”

In previous years, bid amounts were typically closer to project cost estimates and sometimes the bids came in well below the estimates.

Contractors bid below estimates in prior years

From October 2014 through June 2017, the Water Authority received 3-to-7 bids for projects, and the bids were all below agency estimates. Graphic: Water Authority

From October 2014 through June 2017, the Water Authority received 3-to-7 bids for projects, and the bids were all below agency estimates. Graphic: Water Authority

Bousquet said the agency will monitor construction industry cost trends as it continues pioneering projects to serve the region.

“The Water Authority has made an array of innovative infrastructure investments over the past 25 years, including some of the largest projects in the history of the agency, to sustain the $231 billion regional economy,” said Bousquet. “We will continue to develop cost-effective projects to provide a safe and reliable wholesale water supply to San Diego residents.”

First Days Of Water Shutdown Going Well

After the first few days of the aqueduct shut-down, things are going very well in the parts of the Valley Center Municipal Water District affected by the aqueduct shutdown that began February 23 and will continue until March 5. VCMWD Gen. Mgr. Gary Arant told The Roadrunner, “Consumption has been minimal, reflecting only inside domestic use. With the ideal weather condition for having the majority on you imported water supply shut-off. Finally, this is a case where our large water storage volume really pays off.”

OPINION: State Water Project: Our Most Important Infrastructure

Ask me what tops the list of California’s most critical infrastructure, and I’ll tell you it’s the State Water Project. It’s hard to argue with the fact that water is a prerequisite for all life and a healthy economy. That’s why financing the operation and maintenance of the State Water Project in a responsible, cost-effective manner should be common sense — not a political volley that puts California’s lifeline at risk and threatens ratepayers with a surge in water rates that is easily avoidable.

Oceanside’s North River Farms Project Seeks Talks On Water, Sewer, Streets Needs

North River Farms, a proposed development that would bring hundreds of homes, a hotel and commercial properties to a rural area of northeastern Oceanside, returns to the City Council on Wednesday to request a development agreement. Approval of the agreement would allow the developer, Integral Communities, to negotiate the terms of things such as new water and sewer lines, street improvements and affordable housing that the city requires to be included with the project. Further approvals would be required before any construction begins.

Water Main Break Floods Coronado Intersection, Shuts Off Water To Block Of Homes

A water main broke Tuesday in Coronado, flooding an intersection and shutting off water to a block of homes in an outage that was expected to last until early Wednesday morning. Brown water flooded the roadway near Pomona Avenue and Sixth Street about 3:30 p.m., city officials said. A contractor reportedly hit the line, causing the break. Crews from California American Water “committed to work around the clock until the broken water line is repaired,” city officials said on Facebook. Water service was expected to be restored a few hours after midnight.

Sweetwater Authority Infrastructure Investment Secures Safe And Reliable Water For Its Customers

Chula Vista, Calif. – At its June 13 meeting, the Sweetwater Authority Governing Board adopted its preliminary budget for the 2018-2019 fiscal year and accepted and filed a Five-Year Water Rate study. Over the next five years, the Authority will invest $72 million in water quality improvements, a new 36-inch transmission main pipeline, and necessary safety work to the Sweetwater and Loveland Dams.

Once the liners are installed, they are welded together, grout is injected to fill the space between the liners and the original pipe, and cement mortar is applied on the inside of the steel liner. Photo: SDCWA

Innovative Relining Program Reduces Cost, Extends Pipeline Service Life

When the San Diego County Water Authority installed major sections of 66- to 96-inch diameter pipelines in the 1960s, 70s and early 80s, the regional water wholesale agency used cost-saving pipeline material – a combination of steel wires, thin steel pipe, and concrete widely known as Pre-Stressed Concrete Cylinder Pipe (PCCP). Decades later, agencies around the globe realized that some pre-stressed concrete cylinder pipe didn’t last as long as advertised and could fail catastrophically.

The Water Authority deployed a multi-faceted response, using high-tech asset management tools to identify pipeline sections with the greatest risk of failure and a targeted pipeline relining strategy that minimizes community impacts during construction. The agency’s relining program started in the 1980s and ramped up in the early 2000s.  Today, it is on track to complete more than 45 miles of relined pipeline in the next few months.

The current project is taking place deep below the urban streets of La Mesa, California, where the Water Authority and its contractor, L.H. Woods & Sons, Inc., are on schedule to conclude by summer. The delicate, 4.3-mile operation started in September 2017 after years of cross-departmental preparation to ensure the work on the $28.6 million contract could be completed in a cost-efficient fashion without impacting water deliveries. Instead of trenching and removing the old pipe, crews excavate 13 entry portals at strategic points, then insert steel liners into the pipeline using a specially designed cart. When the pipe installation work is done, the portals are backfilled, the streets are repaved, and the pipeline is put back in service for at least another 75 years – at about half the cost of a conventional pipeline replacement project.

Looking for weak spots in system

To identify sections of its 310-mile large-diameter pipeline system that require relining, the Water Authority relies on a suite of high-tech monitoring tools that are part of its pioneering asset management strategy.

Weak spots are often first detected with a “PING!” indicating a snapped steel wire in the PCCP. That sound is relayed through acoustic fiber optic cables – installed as an early warning system inside pipelines – so that Water Authority staff can be alerted by email and cell phone. Each ping is matched with results from Remote Field Eddy Current assessments and visual inspection data, then mapped using Google Earth.

With that information, pipeline segments are plotted on a risk matrix showing the condition and impact of failure. The sections with high risk and high consequence of failure are prioritized for upgrades. On occasion, emergency repairs are required where failure is imminent and the risks are significant. Other, less risky sections continue to be monitored and managed to maximize their service life. This risk-based approach has allowed the Water Authority to avoid more than $200 million in infrastructure spending.

Planning for success requires coordination

Planning for the current project started in 2011. The long lead time was necessary, in part, to coordinate with two of the Water Authority’s retail member agencies that would not be able to take water deliveries from the pipeline when it was down for upgrades. Local or stored supplies in surface water reservoirs could be used in case they were needed during the project.

Critical planning elements also included accounting for other utility assets, property lines and easement rights, environmental impacts, traffic flow and construction noise. Coordination with the local power utility, the regional transit agency and local city officials helped align schedules of concurrent projects, timely address unforeseen conditions and establish relationships to endure potential mid-course project revisions.

During the design phase, Water Authority staff also identified environmental resources requiring protection and mitigation measures. For instance, noise impacts need to be addressed during construction with the installation of large wooden sound walls around work sites. In addition, the plan included with silt fences, fiber rolls and street sweeping to protect nearby waterways from storm water runoff. In addition, an environmental monitor routinely assesses the contractor’s compliance with environmental commitments.

Pipeline relining program extends use 75 years

Relining is often an elegant solution to pipeline deterioration, but it’s not a simple one. The Water Authority’s solution is to use multiple portals, or entry points, to access sections of the pipeline at strategic spots. The footprint of each of the 13 portals for the current project is approximately 25 feet by 60 feet. Photo: SDCWA

Relining is often an elegant solution to pipeline deterioration, but it’s not a simple one. The Water Authority’s solution is to use multiple portals, or entry points, to access sections of the pipeline at strategic spots. The footprint of each of the 13 portals for the current project is approximately 25 feet by 60 feet. Photo: SDCWA

Relining is often an elegant solution to pipeline deterioration, but it’s not a simple one. Crews can’t just insert a single 4.3-mile-long steel liner, partly due to curves and changes in elevation along the route. The Water Authority’s solution is to use multiple portals, or entry points, to access sections of the pipeline at strategic spots. The footprint of each of the 13 portals for the current project is approximately 25 feet by 60 feet. When accounting for laydown, staging and other related work areas, the project encompasses 12.5 acres.

Each portal serves as ground zero for construction, including site excavation and removal of two 20-foot sections of existing pipe to make room for work crews operating the specially designed liner carts. The initial project design identified portals located roughly 2,000 feet apart. However, the contractor adapted its liner carts to better navigate curves and elevation changes. This innovative approach meant the project required fewer portals, saving money and significantly reducing impacts to nearby neighborhoods.

Once the liners are installed, they are welded together, grout is injected to fill the space between the liners and the original pipe, and cement mortar is applied on the inside of the steel liner. To complete the work, new 20-foot sections of the pipe are installed – reconnecting the pipeline through each portal. Then, the portal areas are backfilled, and the portals are returned to like-new condition.

While construction crews carry out that work, the asset management team stays on mission by using removed pipe to perform destructive load testing of pipe sections. On the current project, testing showed steel relining can withstand advanced deterioration of the outside pipe – helping to confirm that steel liners can last at least 75 years.

Reducing neighborhood impacts during construction activities

While the number of portals in the current project was reduced, construction activities remained significant for several months in the highly urbanized area. Four portals were in a four-lane road, temporarily reducing traffic to one lane in each direction. Additionally, two portals were adjacent to major retail parking lots, and six others were less than 100 feet from homes.

From design through construction, the Water Authority conducted significant public outreach, including open house events for neighbors to meet agency staff; distribution of postcards and doorhangers to thousands of neighbors; and the development of “Open During Construction” signs for retail centers. This proactive outreach kept stakeholders engaged with project activities, helping to reduce complaints and resolve issues quickly.

When the current relining project wraps up this summer, the Water Authority will have relined more than half of its pre-stressed concrete cylinder pipelines – a critical part of the agency’s commitment to ensure a safe and reliable water supply that sustains a $220 billion regional economy and the quality of life for 3.3 million residents.