Utah Division of Water Resources Residential Product Study

To evaluate the effectiveness of the Water Reach WR-7 Receiver, two years of water use data-preceding installation is compared with three years following installation. This report presents the results for the 2000-2001 irrigation seasons (prior to installation) and the 2002-2004 irrigation seasons (after installation).

One WR-7 receiver was installed at a residence at 205 N. Wood Hill Ln. in North Salt Lake, Utah. The irrigated area of the residential lot was obtained through Ariel photography and a measuring wheel. Meter readings were obtained monthly from the North Salt Lake Utilities Department. The Department usually reads meters on or around the 15th of every month during the irrigation season. A target usage is calculated using the North Salt Lake Weather Station ET information and multiplying this by the area, dividing by an assumed irrigation efficiency of 70% and then converting that volume into gallons. This target is then compared to what was actually used to see how efficiently the residence is being irrigated. Thus this analysis takes the seasonal weather variability into account.

The following table compares the two irrigation seasons (2000-2001) prior to installation and the three seasons (2002-2004) after installation of the WR-7 receiver.

Irr. Seasons Irrigated area(sf) Target Usage(gal) Actual Usage(gal) Efficiency(%)
2000-2001 9,986 384,000 497,000 129
2002-2003 9,986 497,000 476,000 96

In comparing the two seasons prior to installation and the three seasons after installation this residence has saved nearly 90,000 gallons per year. At the current water rates this family has saved about $112 per year over the last three years. More importantly the WR-7 has helped this residence to irrigate ver efficiently just below the target value. This residence prior to installation was watering fairly well at only 29% above target. The Division of Water Resources has done studies that indicate on average Utah homeowners over-water by about 50%. So to get a reduction in water use from a fairly efficient water user is positive results in the effectiveness of the WR-7 receiver.

As a comparison, this study also wanted to analyze other residences nearby that did not use the WR-7 receiver during both the 2000-2001 (prior to installation) seasons and the 2002-2004 (after installation) seasons. Eight homes on the same street were chosen. All of these have similar lot sizes and similar amounts of turf grass and bushes. The following table shows the combined data of these eight lots for each of the two time periods listed earlier in this study.

Irr. Seasons Irrigated area(sf) Target Usage(gal) Actual Usage(gal) Efficiency(%)
2000-2001 78,625 3,180,000 4,905,000 154
2002-2004 78,625 4,120,000 5,928,000 144

As the data shows, these residences are fairly typical water users. They were over-watering by 54% and have reduced their water use over the last three years by about 6% from the prior two. The statewide water conservation media campaign and the drought response has caused many citizens in Utah to begin implementing water conservation practices. Statewide, the Division of Water Resources has shown that these efforts have resulted in water savings of about 14% over the last four years years.

However, as can be seen by the overall efficiencies presented in the table, it is still very difficult for many citizens to efficiently water their irrigated areas. Even by rescheduling their automatic timers and implementing other water conservation practices these North Salt Lake residences are still over-watered by 44%. Based on results of this study and another study conducted by the Division of Water Resources on six park facilities in North Salt Lake it could be assumed that there are opportunities for average homeowners to save considerable amounts of water by using the WR-7 receiver.