Terrace Heights Water Use Efficiency

Water Use Efficiency Program

The water use efficiency program includes the following items:

  • Description of current water conservation program
  • Description of WUE goals that support the program and how the goals are established
  • Evaluation of WUE measures for cost-effectiveness
  • Description of WUE measures to be implemented to meet established goals for the next six years
  • Description of how we will educate customers to use water efficiently
  • Estimated water savings from selected WUE measures
  • Description of how we will evaluate the effectiveness of the WUE program
  • Evaluation of distribution system leakage
  • A water loss control action plan if the distribution system leakage exceeds the leakage standard
  • Evaluation of rate structures that encourage water demand efficiency
  • Evaluation of reclaimed water opportunities
  • Description of water supply characteristics
  • Current Water Conservation Program

Current Water Conservation Program

Yakima County’s current water conservation program includes:

  • Installation of a new automated metering infrastructure system with all new service meters providing hourly readings and leak notifications.
  • Collecting daily source meter readings.
  • Billing customers based on an inclining block rate structure for all customer classes.
  • Notifying customers when an unusually large water bill is discovered or when the Beacon Advanced Metering Analytics software indicates a possible leak.  A possible leak is indicated if the meter has 24-hours of continuous consumption.
  • Assisting customers in determining if they have a leak by explaining how to use the leak detector on the meter and how to sign up for automated leak detection notices through the Beacon Eye-On-Water application.
  • Assisting customers by using leak detection equipment on their service line if needed.
  • Including occasional water conservation tips in mailings.
  • Conducting leak surveys.

WUE Goals

Water use efficiency goals are intended to help conserve water for future generations and meet the State’s new distribution system leakage standard.  The County’s water use efficiency goals for the Terrace Heights Water System include:

  1. Reduce distribution system leakage to less than 10 percent based on a 3-year rolling average within the next 6-year planning period.
  2. Reduce average day and peak month demands per single-family residence by 3 percent based on the average of the demands over the next 6-year planning period (2017 – 2023) as compared to the average over the previous 6-year period (2011-2016). 

The Board of County Commissioners adopted the water use efficiency goals in January 2010.  A public meeting and a public hearing were held in January 2009. 

Evaluation of Water Efficiency Measures

Measures that must be evaluated for the WUE rule include:

  • Rates that encourage water demand efficiency, and
  • Reclamation opportunities.

These two required measures are described later in this Chapter.  In addition to the required measures, a minimum of five other WUE measures must be evaluated or implemented for a system the size of Terrace Heights.  To satisfy this requirement, the County has implemented the WUE measures described below.

WUE Measures Implemented

Yakima County has implemented several WUE measures.  One such measure is the implementation of a conservation rate structure. Because the WUE rule only requires that conservation rates be evaluated, implementing a conservation rate structure counts as one of the other five WUE measures that must be evaluated.  In addition, the WUE rule allows measures to be counted as multiple measures if they are applied to different customer classes.  Consequently, the County’s inclining block rate structure for single-family, multi-family, commercial, education and government customer classes counts as five conservation measures.

An additional measure implemented is the notification of customers when they have an unusually high water bill or when the Beacon Advanced Metering Analytics software indicates a possible leak. If a leak is suspected, the County meets with the property owner and checks the leak detector on the meter for water usage when the customer has all their faucets turned off. 

Yakima County also shows consumptive history on their water bills.  Like conservation rates, a bill showing consumption history counts as multiple measures if it applies to multiple customer classes. 

Measures currently implemented therefore include:

Measure 1. Conservation rate structure for single-family customers.

Measure 2. Conservation rate structure for multi-family customers.

Measure 3. Conservation rate structure for commercial customers.

Measure 4. Conservation rate structure for education customers.

Measure 5. Conservation rate structure for government customers.

Measure 6. Notifying customers about leaks on their property.

Measure 7. Showing consumptive history on water bills for single-family customers.

Measure 8. Showing consumptive history on water bills for multi-family customers.

Measure 9. Showing consumptive history on water bills for commercial customers.

Measure 10. Showing consumptive history on water bills for education customers.

Measure 11.Showing consumptive history on water bills for government customers.

In addition to the measures above, WUE measures that must be implemented include:

  • Installing source and service meters
  • Performing meter calibration
  • Implementing a water loss control action plan to control leakage
  • Educating customers about water use efficiency practices.

Source and service meters have been installed.  Source meters have been installed since before the County assumed ownership of the system in the 1990’s.  Service meters were installed just after the County assumed ownership of the system, with the exception of one service to Well #4 which was installed later.

Source meters were tested in May 2017 by a private contractor.  All of the meters tested within 1% of the indicated flow.  The County intends to retest the source meters once every two years.

 All service meters were replaced in 2014 as part of an Automated Metering Infrastructure (AMI) project.  Prior to that time, meter calibration was limited to testing a small number of service meters.  Meters tested were within standards.  The County plans to develop a process and timeline for inspecting, testing, calibrating, and replacing meters based on recommendations from the manufacturer and the American Water Work’s Association manual entitled “Water Meters-Selection, Installation, Testing, and Maintenance (M6)”.  The 8-inch and 3-inch service meters will be tested along with the source meters. 

Customer Education

The WUE rule requires the County to educate their customers about the importance of using water efficiently.  The County provides water conservation tips in their annual consumer confidence report and occasionally in the customer’s monthly water bills.  Examples of the water conservation tips are included in Appendix U.  Appendix J of the Department of Health’s Water Use Efficiency Guidebook has good water conservation tips.  Water conservation brochures are also available from the Department of Health’s website.

WUE Program Effectiveness Evaluation

Water saved as a result of the above program has been good.  In the last 6-years, average day and peak month demands per single-family residence in the Terrace Heights area were down 6% and 10% respectively, based on consumption records.  Over the same time period, supply records showed an 8% and 11% decrease in both average day and peak month demands.  A summary of the reduction in demands is included in Table 6-1.

Table 6-1
Water Use Efficiency Program Effectiveness


 Average Day Demand 

(gpd/single-family residence)

 Peak Month Demand

(gpd/single-family residence)

Based on Consumption Records

Based on Production Records

Based on Consumption Records

Based on Production Records

 Terraced Estates

  Average for 2005-2010

  Average for 2011-2016

  Percent Decrease















 Country Club

  Average for 2005-2010

  Average for 2011-2016

  Percent Decrease














 Combined Percent Decrease in Single-Family Residential Demand






  1. Water Use Efficiency goal includes a 3% reduction in single-family residential average day and peak month demands between 6-year planning periods.
  2. The combined percent decrease in single-family residential demands is based on 794 single-family residential customers in Terraced Estates and 678 in Country Club at the end of 2016.

Estimated Water Savings

The projected water savings from the selected WUE measures can be difficult to estimate when weather variations and new customers are considered.  However, based on the reductions observed in single-family residential consumption the last 6-years as compared to the previous 6-years, the estimated water savings in just residential consumption is 1.2 million cubic feet per year.

Distribution System Leakage

Distribution system leakage for the last 3 years has averaged 12 percent. Prior to replacing the service meters, distribution system leakage averaged 23 percent.  A summary of distribution system leakage is presented in Table 3-13. 

Table 3-13

Distribution System Leakage



(cubic feet)


(cubic feet)


(cubic feet)

 % Leakage


 3-year Running Average
























































  1. In 2014 the County installed new service meters. 

The majority of the remaining distribution system leakage appears to be due to leakage, since the total water loss is about the same during the winter as it is in the summer. 

Some of the leakage is likely due to construction projects, such as the recent Reservoir #4 project.  In recent years, Yakima County has placed greater emphasis on metering consumption from fire hydrants and construction projects and now owns 4 hydrant meters to rent out to contractors.  Yakima County will continue to emphasize the importance of metering hydrant usage.

Water Loss Control Action Plan

The County will continue to monitor distribution system leakage and if it is greater than 10 percent, then the County will perform a new leak detection survey.  Prior to performing a new leak detection survey, the County will compare Beacon water consumption records for pressure Zones 1 and 1a with well and booster station pumping records to get an idea if the leakage is occurring above or below the Sycamore Booster.  The County will also consider performing an International Water Association water audit. 

A leak survey was completed in 2008 in the older part of the system that identified eight minor leaks.  Six have been repaired and a seventh was excavated but not found.  The remaining leak cannot be heard with the County’s equipment and is being monitored.  A leak survey was done on the remainder of the system in 2009 and three small possible leaks were found.  None can be heard with the County’s equipment and are being monitored. 

Future leak surveys and other distribution system leakage costs including repairs will be covered by water system reserves.

Rate Structure Evaluation

One of the measures that must be evaluated is a rate structure that encourages water demand efficiency.  Yakima County first implemented an inclining block rate structure in 1994 to encourage efficiency.  Current consumption rates start out at $1.58 per 100 cubic feet for the first 1,000 cubic feet, then increase to $1.75 per 100 cubic feet for the second 1,000 cubic feet, and then increase to $1.92 per 100 cubic feet for all consumption over 2,000 cubic feet.  The rate structure is the same for all customer classes.

Reclaimed Water Opportunities

The WUE rule requires the County to collect information on reclaimed water opportunities and include that information in the water plan.  As a minimum, the information should include:

  • Where reclaimed water could potentially be used, such as parks, golf courses, groundwater recharge facilities, and car washing facilities.
  • Where reclaimed water production facilities exist and the locations of reclaimed water distribution lines.
  • Any barriers to the use of reclaimed water, such as cost, permitting issues, water rights mitigation, and local regulations that govern the use of reclaimed water.
  • Contractual obligations and agreements that limit the use of reclaimed water.
  • Where reclaimed water is used or proposed to be used. 
  • The County’s efforts to develop the use of reclaimed water.

There are currently no water reuse facilities, either sources or users, within the Terrace Heights service area and the number of potential sources is very limited.  There are no fish hatcheries, stormwater impoundments, or sewage treatment facilities in the service area.  The most likely places where reclaimed water could be used include a golf course and a cemetery. 

The only known barrier to the use of reclaimed water is the cost.  Without a nearby source, the cost to pipe reclaimed water would be high.  There are no contractual obligations or agreements that limit the use of reclaimed water.  The County has not pursued development of reclaimed water due to the limited sources and cost. 

Water Supply Characteristics

The Terrace Heights Water System includes six supply wells.  Wells 4, 5 and 6 draw from the Ellensburg formation, which consists of semi-consolidated deposits of clay, silt, sand and gravel.  Well 3 draws from the Saddle Mountain formation in the Yakima Basalt aquifer, which underlies the Ellensburg formation.  Well 1 draws from the Wanapum and Well 2 draws from the Lower Ellensburg.  Information regarding each well, including capacity, was included in Chapter 2. 

The U.S. Geological Survey conducted a detailed study of the ground water sources in the Yakima River Basin.  Results of the study indicated water levels were relatively stable in the Terrace Heights area (Township 13 Range 19).  USGS’s data showed a few wells with 5’ of decline.  East of Terrace Heights in the Moxee Valley, declines in the ground water level increased.  Township 13 Range 20, which is six miles to the east of Terrace Heights, had some wells with declines of 40 to 50-feet in the Saddle Mountain and Wanapum aquifers.  In Township 13 Range 21, the declines were worse.  According to USGS, the declines were primarily in the basalt and deeper Ellensburg wells (wells over 1000’), although they also claimed the bottom of the Ellensburg can be course grain and very productive.  The upper Ellensburg formations are recharged in part by irrigation and irrigation canals and are not experiencing the declines seen in the basalt wells.  The recharge is estimated to be 10 to 20-inches per year.

According to USGS, water levels decline in the basalts during drought years due to increased pumping from irrigators with junior surface water rights.  During drought years, irrigators with junior surface water rights resort to using their groundwater wells. 

Wells to the north along Yakima Ridge are also experiencing declines.  This is said to be due to the wells being located along the anticline of the ridge rather along the syncline of the valley.  The Terrace Heights Well #2 is an example of this.  This well has experienced nearly 80’ of decline since it was drilled. 

Seasonal variations do not have an impact on the ability of the Terrace Heights wells to meet demands.