Helix leverages drone technology

Helix leverages drone technology

Helix Water District is now utilizing drone technology to view and monitor district storage tanks.

Helix recently used drone technology to inspect its Fletcher Hills Combo Tank, which is located near Grossmont College in El Cajon. The top of the tank sits at a height of 120 feet and the district needed to inspect the tank’s air vents, located at its outer edge. Inspecting the Combo Tank vents has proven challenging over the years. Inspecting the vents from the exterior required district inspectors to walk along the edge of the 120-foot high tank. The use of appropriate safety equipment to perform the inspections was cumbersome and expensive and did not eliminate all risk to the inspectors. Inspecting the vents from the interior required taking the tank out of service. Seeking a safe and cost-effective alternative, Helix Cathodic Inspector Eric Fockler suggested using a drone to view the vents’ condition.

The resulting photos and video imagery allowed Helix staff to perform this inspection, less expensively and without placing any staff members at risk. “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.”

Drones will also be used to inspect interior roof supports of the district’s storage tanks. These supports are well above the tanks maximum water level but are especially vulnerable to corrosion since they are constantly exposed to humidity and heat. Inspecting these components requires taking the tank out of service and viewing the roof supports by using a moving 30-foot high scaffolding. The scaffolding is assembled and brought in piece by piece through the tank’s 36-inch access-ways on the sidewalls. The scaffolding is then moved around the tank from one support to the next which is both labor and time intensive. Drones can accelerate this process by surveying each bracket inside the tank and allowing district crews to use the footage to decide which supports need refinishing.

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

Helix Water District provides water treatment and distribution for 275,000 people in the cities of El Cajon, La Mesa and Lemon Grove, the community of Spring Valley and areas of Lakeside — east of downtown San Diego. Helix also provides treated water to neighboring Padre Dam, Otay and Lakeside water districts.

Video: South Rim Tank Rehabilitation

Video: South Rim Tank Rehabilitation

The South Rim Tank in El Cajon is one of Helix Water District’s 25 drinking water storage reservoirs. Originally built in 1956, this 1 million gallon steel storage reservoir was beginning to show its age. 

In service for 6 decades, the steel roof suffered from corrosion which prevented the tank from being operated at full capacity.

However, with the rest of the tank still in good condition, the district was able to replace the roof and rehabilitate the tank. Rehabilitation projects utilize existing structures in the rebuilding process and are less a expensive alternative than demolition and installation projects, saving the district and ratepayers money.

Watch our brief video showing the construction process and see the improvements for yourself!













Notice of Intent to Adopt a Mitigated Negative Declaration

Notice of Intent to Adopt a Mitigated Negative Declaration

Notice is hereby given that, in accordance with the California Environmental Water Quality Act, Helix Water District has completed an Initial Study of its Pipeline Project 4241, located in the unincorporated community of Spring Valley, California, within the East County region of San Diego County.

These documents are required to be posted to the Helix Water District website December 1 to December 31, 2017.

Notice of Intent to Adopt a Mitigated Negative Declaration-Work Order 4241

Helix Water District Pipeline Project 4241-Draft Initial Study-Mitigated Negative Declaration-November 30, 2017

Water Authority relining pipe under La Mesa and Spring Valley

Water Authority relining pipe under La Mesa and Spring Valley

In late September, the San Diego County Water Authority will begin rehabilitating more than four miles of a large-diameter pipeline between Lake Murray and Sweetwater Reservoir. The 66-inch and 69-inch diameter pipe provides water to Helix Water District and the Sweetwater Authority.

The pipeline runs under Baltimore Drive and along Spring Street in La Mesa, and extends south into Spring Valley. The $28.6 million project is part of the Water Authority’s multi-decade program to rehabilitate 82 miles of pre-stressed concrete cylinder pipeline in its conveyance system.

Click Here for Project Map

Construction crews will conduct most of the work underground, inside the pipe. They will access the pipe by excavating and entering the pipeline through 17 access sites, or portals. Most construction activities will occur at these access portals, which will be spaced approximately 525 to 2,500 feet apart.

The Water Authority began communicating with stakeholders along the pipeline last December. If you’d like to know more about the project, the Water Authority will host two open houses in September for residents living near the project and provide information at local events:

August 31st
Information table and staff to answer questions at the La Mesa Car Show

September 7th 
Open house at Portals 1 and 2
– Portal 1 is located on Baltimore Drive, just south of Laport/El Paso Street, in La Mesa
– Portal 2 is located on Baltimore Drive, just south of Bertro Drive, in La Mesa

September 14th
Open house at Portal 3
– Portal 3 is located on Baltimore Drive, about 3/4 mile south of Lake Murray Blvd.

September 27th
Information table and staff to answer questions at the La Mesa Chamber of Commerce breakfast

September 29th
Information table and staff to answer questions at the La Mesa Farmer’s Market

Explore the Project @ SDCWA.org

Last stretch of cast iron pipe removed in Lemon Grove

Last stretch of cast iron pipe removed in Lemon Grove

Photo:  from right: Helix Boardmember Mark Gracyk, who represents Lemon Grove, Boardmember DeAna Verbeke, Board President Joel Scalzitti and Lemon Grove assistant city manager and public works director Mike James.

Helix Water District Board President Joel Scalzitti operated the excavator this morning, lowering a segment of PVC pipe into the trench at the corner of Mt. Vernon Avenue and Golden Avenue in Lemon Grove.  The pipe was signed by the Lemon Grove City Council and Helix board members, and its installation marks the removal of the last large segment of cast iron pipe in the water distribution system serving the city of Lemon Grove.

In addition to president Scalzitti, Helix board members Mark Gracyk, who represents Lemon Grove, and DeAna Verbeke were on site to mark the milestone in Helix’s Cast Iron Pipe Replacement Project. Also on site were Lemon Grove assistant city manager and public works director Mike James, and Helix’s general manager Carlos Lugo, director of engineering Jim Tomasulo and director of operations Kevin Miller.

“This is an important milestone for our engineering team and for our Lemon Grove customers,” said Lugo. “Each segment of cast iron pipe we remove reduces the possibility of pipe breaks and service interruptions.”

Cast iron pipe was the most commonly used pipe material in Helix’s water distribution system from about 1926 to 1949. By 1959, Helix’s system included 185 miles of cast iron pipe. In 1963, however, the number of leaks from the district’s cast iron pipes reached 1.5 per 10 miles of pipe – just under 30 leaks a year.

In 1967, the district committed to replacing all cast iron pipe. In 2005, the board approved the Cast Iron Pipe Replacement Project for the replacement of the remaining 67 miles over the next 20 years.

The success of this project is largely due to a protocol developed by Helix’s engineers for assessing and prioritizing which pipes to replace first, based on prior history of pipe breaks, soil conditions, water pressure in the pipe, and the potential for property damage if a break were to occur.

“The prioritization was effective,” said Tomasulo. The number of cast iron pipe leaks per year dropped from 3.5 per 10 miles of pipe in 1973 to less than one per 10 miles of pipe in 1999.

Helix is replacing approximately 15,000 linear feet of cast iron pipe per year and, at this rate, will complete the program in 2026.

Photo:  Lemon Grove city council. From left: Councilmember Jerry Jones, Mayor Racquel Vasquez, Mayor Pro Tem Jennifer Mendoza, Councilmember David Arambula and Councilmember Matt Mendoza.

Water, gravity and Fletcher Hills’ new pump station

Water, gravity and Fletcher Hills’ new pump station

Rendering: the current Fletcher Hills 2 Pump Station is located between the Aldwych Reservoir Tanks. The new station will be built west (left) of the tanks, as shown.

Ever wonder what a pump station is for and why we need them? Check out the new pump station project Helix will be constructing over the next year! This station will serve the Fletcher Hills area and provide enhanced reliability.  Last spring, the District met with residents in the immediate area surrounding the new station site to discuss the project during the initial phases of design. Now that the project design is complete and the construction contract has been awarded, a follow-up meeting has been scheduled for 9:30 a.m. on Monday, October 24 at the Aldwych Reservoir Tanks.

Pump Stations 101

The new station, called the Fletcher Hills 2 Pump Station, is one of 25 pump stations within Helix’s water distribution system. They play a critical role: filling reservoirs and pressurizing water mains.

Helix’s 25 Pump Stations







Many of you reading this are probably familiar with the basic concept of water distribution, which is to pump water to reservoirs on hilltops, and let gravity distribute the water to homes, schools and businesses. This is the most energy efficient way to operate a public water system.

A public water system, like Helix, strives to maintain water pressure at an adequate level for every customer. Water pressure is the force exerted per square inch (psi) of wall – whether in a reservoir, a water main or the pipes in your home.  If water pressure is too high, pipes burst. If it’s too low, firefighters can’t put out the fire, and you can’t take a morning shower, do laundry and irrigate at the same time.

The catch is that water pressure is directly related to elevation, or more specifically, the height of a water column. One foot of water height is approximately equal to 0.434 psi.  So, if we provide 50 psi to customers near the top of Mt. Helix at an elevation of 1,300 feet, the water pressure for customers at a low elevation, for example, the western edge of Lemon Grove, elevation 270 feet, will be 497 psi.

(1,300 – 270) x 0.434 = 447 psi

50 psi + 447 psi = 497 psi

The solution to this issue is to serve water to customers at different elevations, such as Mt. Helix and at the western edge of Lemon Grove, from different reservoirs. In fact, we group customers over the 50 square miles based on their elevation and we serve into 33 pressure zones. The zones are isolated from each other with specialized valves and each zone has its own reservoirs and pump stations. Check the map to see which zone you are in.

Map: Ctrl-click then click “open image in a new tab” to see a larger map.

Fletcher Hills 2 Pump Station

The Fletcher Hills 2 Pump Station pumps water from the Aldwych Tanks (that serve the Aldwych pressure zone) into the Fletcher Hills Combined Tank that serves the Fletcher Hills pressure zone.

Photo: Helix stores water in the saucer shaped section of the Fletcher Hills Combined Tank.

Diagram: note the elevation gain from the Aldwych Tanks to the Fletcher Hills Combined Tank.

The Fletcher Hills Combined Tank is actually two tanks in one — Padre Dam Municipal Water District operates the lower, cylindrical section and Helix utilizes the higher elevation, saucer section.  The saucer is at a higher elevation than Helix’s old tank, which was demolished to make way for the 125 freeway, and provides higher water pressure for customers in the Fletcher Hills pressure zone.

The Fletcher Hills 2 Pump Station now must pump to a higher elevation than it was originally designed to handle, requiring both of the station’s 50 horsepower pumps to operate simultaneously. Neither pump can be taken offline for maintenance.  The industry term for this is lack of redundancy, and Helix requires redundancy in all facility designs to ensure a reliable water supply. Even our water treatment plant has two of everything.

The new pump station includes three pumps that are capable of pumping 2,000 gallons per minute more efficiently than their predecessors. The third pump is a standby unit, allowing maintenance of the other two.  The state of the art design also includes automated control valves, flow metering, electrical switchgear and instrumentation coordinated with the district’s SCADA control network.  

Rendering of new pump station

Current pump station

Helix maintains and replaces our pump stations as needed, and nearly all of our older stations have been improved at some point to ensure reliable service. The average age of our pump stations is 33 years old. If you want more information about the Fletcher Hills 2 Pump Station, please feel free to contact Helix Water District’s Engineering Department or click on the following link. 

Learn More

Surveying Helix Water District

Surveying Helix Water District

Helix Water District’s survey crews have been an integral part of the District’s day to day operations since the early 1900’s. In those early days, survey work was performed with levels to measure elevation, transits to measure horizontal and vertical angles, and chains to measure distance.

While the type of work we do has remained the same — providing Helix engineers with critical data for planning, design and construction — those early tools have been updated by advancements in technology.

Surveyors use levels to measure elevation. At right is a model from the early 1900s and a model used today.

Photo of a Theodolite, which surveyors use today to measure angles.
Photo of a surveyor's transit from the early 1900s. A transit measured horizontal and vertical angles.
Photo of a surveyor's transit from the early 1900s. A transit measured horizontal and vertical angles.
Photo of a Theodolite, which surveyors use today to measure angles.

Transits are used to measure angles.  At left is a model from the early 1900s and a model used today.

Today, Helix crews are equipped with GPS (global positioning system) receivers driven by electronic data collectors connected via Bluetooth technology, and synchronized via modem with a real-time network that allows for instantaneous positions that are accurate within one centimeter. This new technology also saves time by eliminating line-of-sight obstacles and heat wave refraction. It reduces the chance of equipment theft, as well, since our equipment remains with the survey crew at all times.

How Surveying Supports Project Design

These advancements allow Helix survey crews to perform highly accurate surveys at any position within district boundaries. And, keeping all projects and facilities tied into one coordinated system allows for seamless data transition into our districtwide GIS (geographic information system) database. These capabilities are vital during the design of new projects, such as the replacement of cast iron pipeline and the construction of new reservoir tanks. Survey crews collect existing topographic features, ground elevations, and utilities locations in the field, then download the data into AutoCad files and send it to engineering staff for design.

Left: Dave Moore, Survey Technician, and Scott Gregg, Senior Survey Technician, staking out pothole locations for a capital improvement project and recording each location with GPS. Right: Cameron Scott, Survey Technician, using GPS to locate an existing pipeline for a large valve replacement project.

How Surveying Supports Construction

Helix’s surveyors also locate existing boundary (property) line monuments to ensure that new facilities are located within established easements and right-of-way. Once these projects are designed, survey crews return to the field and provide construction crews with survey stakes to ensure accuracy of construction. Quite often, construction crews must remove a property line monument in the work area. Before they do, the construction crew will contact the surveyors to document its position.

When construction is completed, the survey crew will replace missing monuments in the original’s exact location and Helix will draft and submit a map to the County Surveyor office to be recorded. The crew will also collect final as-built locations for inclusion in the record drawings inserted into Helix’s GIS system. Collecting these accurate locations helps ensure that facilities can be easily found in the future for mark-out, repair or replacement.

Monitoring Easements

Survey crews also work closely with Helix’s right-of-way staff, monitoring Helix’s easements and main transmission lines quarterly to ensure that no new construction has infringed upon or blocked access to an easement and that Helix’s facilities are not damaged.

As Helix moves ahead in providing our customers with safe, dependable drinking water, the Survey Department will be there, continuing to play its vital role in maintaining the district’s infrastructure.