Sustainable Water Savings for Irrigation Systems

Landscape Irrigation Systems And Implementing Changes For Less Water Use & Long Term Sustainability Presented By Larry Keesen Keesen Water Management

What we’ll Cover:
Audit Recommendations That Will Work.
Design for Existing Irritation systems.
Quality Monitored Installation.
Proper System Operation & Maintenance.
Develop Water Budgets & Monitor Actual Use.

Audit Recommendations Will They Work?
Smart Controllers & Rain Sensor. OK
Replacing Heads with Pressure Control & Check Valves if Head Spacing is “Head-to-Head”. Usually.
Control High Pressure - Pressure Reducing Devices. OK
Increase Low Pressure-Lower Flow Nozzles. Caution .
Replace Spray Nozzles with Rotator Nozzles. Caution . (Application rate is Lower & More Runtime is Required.)

Audit Recommendations Will They Work? (cont.)
Raise Heads if Spray is Blocked by Turf. Yes
When Distribution Uniformity is Below 60%:
And one or more apply:
Pressure at heads are to low to meet recommended optimum operating pressure.
Head Spacing is erratic and stretched.
The system is over 30 years old.
Then consider:
Installation of a New Irrigation System. Best

Design for Existing Irritation systems.
Distribution Uniformity Above 70%.
Correct Water Pressure at the Head.
Consider Rotator Nozzles.
Use Subsurface Drip for Turf & Beds.
(Highest Uniformity at 90% or Higher.)
Limit Run Time to 10 Hours per Day.
Zone for Exposure & Application Rates.

Quality Installation.
Precise Spacing of Sprinkler Heads.
Correct Nozzles & Arc Settings.
Heads Set Plumb & at Correct Height.
Verify Water Pressure at the Head.
Designer C heck for Proper Installation
Furnish “as-built” record drawings.

Proper System Operation & Maintenance.
Post Operating Schedules & Zone Location Map in Clock.
Reset Controllers Monthly According to Seasonal Demand.
Check, Adjust & Repair Equipment Weekly After Mowing. Identify System Leaks & Repair Promptly.
Inspect System at Activation & Verify Pressure is Same as Previous Year.
Replacement Hardware for Repairs Must Match Original Equipment.
Require an Audit Every 5 Years by a CLIA.

Water Budgets vs. Actual Use.
Water Budget is Based on Historical ET.
Water Budget for Turf Should not Exceed:
15 Gallons / 24 Inches per Square Foot.
For Plants See GreenCO BMPs, Appendix E: Plant Water Requirement Estimates.
Monitor Water use vs. Water Budget.
Give Budget to System Operator.

Sustainable Water Savings
Benchmarks to Determine Turf Water Savings
Average annual historical ET for turf grass is 30-inches.
Add system efficiency at 80% & the turf water requirement total is 24-inches or 15 Gal. annually per sq. ft.
Document metered water use & savings after renovation.
Our experience with project water savings and the various results are documented on the following pages:

Pilot Program 2000
ECCV Water District sponsored Greenfield /Liverpool Irrigation System Evaluations & Pilot Program.
Two streetscapes across the street from each other.
The problem symptoms with these new systems were runoff, overspray, and high water bills.

Pilot Program (cont.)
Results from the Greenfield /Liverpool streetscape system evaluation in 1999:
High water usage:
Greenfield 61.7-inches/38.5 gal. sq. ft.
Liverpool 63.0-inches/39.3 gal. sq. ft.
Heads installed too low – spray blocked
High pressure – up to 78 psi
Low head drainage
Low pressure in some areas–as low as 15 psi

During the winter of 1999-2000 the Greenfield/Liverpool irrigation systems were renovated.
New spray heads were installed with 4-inch pop-up height, check valves and pressure control. New nozzles were installed to better control the spray.
Check valves were installed in rotors.
Rain & freeze sensors were installed on controllers.
Goal was to be at 30-inches annually or lower.

Actual Annual Historical Water Use in Inches/Sq. Ft. Before After
Site: 1998 1999 2000 2001 2002 2003
Greenfield 63.9 61.7 77.3* 50.1 42.6 39.5
Liverpool 49.0 63.0 30.0 28.5 22.6 19.6
Under Construction
The same contractor was operating both Greenfield and Liverpool in 1999. Separate contractors were used in 2000.
ET in 2000 increased 14 % above 1999 ET
*Swimming pool overflowed several times during season.

Actual Water Savings:
Greenfield 2001 usage went down from 61.7 to 50.1-inches.
Swimming pool overflowed several times in 2000, data was unreliable.
2001 usage down by 20 % .
Three year savings of 2.7 million gallons or 8 acre feet.
Liverpool 2000 usage went down from 63.0 to 30.0-inches.
Down 53 % first year.
Four year savings of 4.5 million gallons or 14 acre feet.

Renovation Costs and Savings
Total
Site: Area Renovation Cost Payback Water Savings
Greenfield 82,740 $ 11,100.00 4.7 years $ 7,155.00-3 year
Liverpool 47,880 $ 7,492.00 2.9 years $11,379.00-4 year
Water Savings: 2000 2001 2002 2003
Greenfield $ 0 $ 1,463.00 $ 2,421.00 $ 3,272.00
Liverpool $ 2,214.00 $ 2,521.00 $ 2,952.00 $ 3,691.00
What Happened?
Both sites were identical and in the same area.
The big difference was in the way the systems were operated.
Separate contractors were maintaining Greenfield and Liverpool and both were given instructions on how to operate the system.

How the results could have been improved
Installation of flow sensor & central control.
Installation of ET controllers.

Conservation Pays for itself
The Pilot Program clearly showed that water conservation guidelines, coupled with proper renovation of existing irrigation systems can save water, and much more can be saved if the irrigation system is operated and maintained properly .

The Meadows
The Meadows, Castle Rock
In 1994, we performed an irrigation system evaluation for The Meadows Metropolitan District 37-acre streetscape. Water use was 47-inches Sq. Ft.
In 1997 the irrigation system was renovated with conservation design and equipment. The Town of Castle Rock agreed to loan the money to the Metropolitan District and also agreed to pay future water costs if we saved 30 percent on water use.

The Meadows (cont.)
Year Gallons Inches/SQ. FT. $ COST/VALUE SAVINGS
1996 44,500,000 47 $89,890.00
1997 19,051,000 19 $38,483.00 57%
Annual Savings : 25,449,000 gallons, 78 acre feet, 28-INCHES, $51,407.00
The City of Castle Rock, Colorado now pays the water costs and Keesen Water Management, Inc. has received a Water Conservation award from the Associated Landscape Contractors of Colorado.

VILLAGE at FOUR LAKES 37.2 38.3 37.8 ANNUAL ET INCHES: 15.2 11.3 13.9 10.5 8.0 11.1 23.8 23.3 ANNUAL GAL/SQ.FT. 24.4 18.2 22.3 16.8 12.8 17.7 38.2 37.4 ANNUAL INCHES/SQ.FT . 11.48 Acres: 500,000 AREA SQ FT: 7,610 5,665 6,941 5,250 3,994 5,528 11,905 11,646 IRRIGATION USE m/GAL: 2008 2007 2006 2005 2004 2003 2001 2000

Summary
Conservation works when irrigation systems are properly designed and installed, but greater savings can be obtained when experts operate & audit the irrigation system.
Key elements for landscape water conservation.
Efficient Irrigation Design & conservation equipment.
Construction Quality Control
System Operation
Regular Maintenance.

Sustainable Water Savings for Irrigation Systems

by Kauhna on Jul 28, 2009

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Sustainable Water Savings for Irrigation Systems — Presentation Transcript