Repair Chronology: 2/18/2020

On Sunday (2/9/20) at 4:33 PM an automated low tank alarm was generated by our SCADA computer and shortly after 5 PM a large volume of surfacing water was located at the Cholla pavement switchback in front of 3645 Cholla Court. This is a critical section of water main between our water treatment plant and water tank above Cholla Court. Based on the tank draw-down of approximately 70 gallons per minute and our concurrent pumping rate of 50 gallons per minute, the water loss of 120 gallons per minute was rapidly draining the tank in spite of our maximum pumping volume.

A water emergency broadcast was immediately sent to our member households and one of our preferred repair contractors was scheduled to begin work Monday after required utility locations were obtained. When the repair crew and backhoe arrived on Monday, excavation could not begin until the repair site and steep road were cleared of snow and ice. Excavation and additional clearings continued in cold and snowy weather through Thursday, but following the path of the surfaced water has not yet located the source of the leak. The slow progress is complicated by the succession of unmarked utilities (gas, electric, sewer, and cable) which requires additional locates and careful hand excavation.

In order to provide water service to member households whose taps are on water main segments below Cholla, on Tuesday night we closed the Cholla valve and engineered a hydrant exhaust which enables the small well to provide continuous reduced-pressure emergency water to the lower households. As a result, only 4 occupied homes are without water, 2 of which are also without sewer.

However, this emergency supply is provided at a significant risk. In addition to the potential for damage to system components, continuous pumping costs about 24,000 gallons daily, most of which is wasted but counts against our limited water rights adjudication. Long-term operation of this emergency water supply may jeopardize both outside irrigation and domestic water use later in the year.

Based upon our compilation of historical system repairs, main breaks on Cholla Court are some of the most challenging due to the steep topography, poor access, limited work space, and multitude of undocumented and commonly-bedded utilities in and around the narrow private roadway. This particular break is especially problematic because it is in an area where precise main location is not available and the visible surfacing water appears to be flowing uphill from the where the actual leak is. The majority of surfacing water is now suspected to be hidden by the snowy field below the road. Until the contractor actually locates the break, we do not know.

Because of the dangerous road and site conditions, we do not encourage members to visit the repair site, but the following photos were provided by water board members Ed Arnold and John Allen.

Update 3 PM 2/13/2020: The repair crew located the main break and installed one of the repair clamps from our pumphouse inventory. Jake is currently charging the Cholla main segment to pressure test the clamp repair.

Update 4 PM 2/13/2020: Low pressure testing of the clamp repair was successful so we have switched over to the main well (50 gpm) for faster tank replenishment and higher pressure testing of the repair.

Update 5 PM 2/13/2020: The tank is slowly filling and is now at about 3 feet (14' is full). ORC scheduled required water testing for Friday morning.

Update 5 PM 2/14/2020: The tank fill completed overnight but additional system damages occurred during completion of the repair. Water currently cannot be provided either from the tank or from the pumphouse. Residents are advised not to draw any water until additional repairs are completed.

Update 6 PM 2/15/2020: The rupture in the finished water supply line leading from the pumphouse was temporarily patched and the emergency water supply described above has been re-established. This provides water service only to households whose taps are on water main segments below Cholla, leaving 4 occupied homes without water. Residents are advised that this emergency water should not be used for human consumption until testing and health clearances are obtained.

Update 10 AM 2/18/2020: On Monday, the temporary repair to the finished water supply line was replaced with a segment of PVC main which is stronger and extends beyond the homeowner's back yard so future main replacement will not cause further disturbance. Following the replacement, emergency water service from the small well was re-established. On Tuesday, the Cholla main segment was carefully checked, charged, and reconnected to the remainder of the system, the temporary hydrant bleed-offs were closed, and the tank discharge valve was opened, reconnecting the tank with the pumphouse. The control system was switched back to its normal automatic mode and the supply switched over to the large well to refill the tank and give the small well a well-deserved rest.