Halton Region Irrigation Retrofit Research

Presented by : Kathy McAlpine-Sims, Water Efficiency Program Manager, Halton Region

Chris Le Conte, President, SMART Watering Systems Inc.

January 10, 2011.

Agenda

• Purpose of the study

• How site and zones were chosen

• Study methodology

• Review of data

• Observations

• Conclusions

Study Overview

• SWS and Halton Region staff identified 2 irrigation zones at a Commercial building in Halton Region that had potential for water efficiency improvements.

• SWS performed upgrades to these irrigation zones and attempted to gather data in order to quantify water savings as well as determine potential return on investment scenarios and perspectives.

Looking Beyond The Controller

• What are the effective ways of reducing water use beyond control systems?

• Are rebates/incentives on Rotary nozzles or other products a solution?

• Where can they be applied? What problems do they solve?

Purpose of Testing Retro-fit Solutions

• Identify & Reduce water waste through irrigation retro-fit.

• Reduce or eliminate water lost to hard surfaces.• Establish best retrofit solution for uniquely shaped

irrigation zones.• Determine if retrofits can be cost effective.• Quantify amount of water run-off.

Product Options and Costs

• Need to indentify products readily available in the

market, on shelves.

• Are rotary nozzles a solution?

• Is sub-surface “drip” irrigation a solution?

• Is pressure regulation a solution?

• What is the return on investment for property

owners?

Retrofit 1- Spray to Drip Line-Zone 4

Retrofit 1- Spray to Drip Line-Zone 4

Why Zone 4?

• Visible water waste observed.

• Zone 4 is nearly all perennials and could be

retrofitted with relative ease.

• Zone 4 was observed to be losing water to

obstructions and hard surfaces.

• Estimated 50-70% not reaching target area.

Why So Much Water Loss?

• 16 spray-heads on risers spaced 15’ apart.

• Single row spacing (saves money)

• Many years (10-15) since install, nozzles are mixed.

• Heads placed on 24” risers to get over plant material.

• As a result more water lands on hard surfaces than

plant material.

• Plant obstruction causing waste.

After the dripline installation

Pressure Regulation & Filtration

• Retrofit product fits in

spray-head bodies.

• Brings pressure to 30

psi.

• Includes fine mesh

filtration.

Drip Operating

Rate of Flow Measurement

• A GE Ultrasonic portable flow meter was used to take flow readings in GPM at the water source.

• Before the drip installation zone 4 had a flow rate of 85 litres per minute.

• After the retro-fit zone 4 had flow rate of 84 LPM.

• Was there an improvement with efficiency?

Before and After

• Drip Irrigation provides 90% uniform water coverage.

• Minimal evaporative losses.

• Run-off and overspray are reduced completely.

• Water is not leaving the target area.

• Ability to water outside of the normal “window” and potentially reduce runtimes.

Yes!

Are there negatives?

• Yes, Drip retro-fit’s can be time consuming, especially when facing mature perennials.

• Significant labour costs (time).

• If landscape maintenance personnel are not aware of the sub surface system, damage can occur. (this is a significant issue as damage has already occurred).

Observations from drip retro fit

• Approximately 70% was being lost/wasted to hard surfaces and obstructions.

• Retro-fit resulted in eliminated water waste.• Before retrofit – 84m3/year was used with a potential

loss 59 m3/year• With drip retro-fit – 83m3/annual usage but the losses

are negligible.• Water waste to hard surfaces is reduced by

59,000 litres.• Run time reduction is achievable as well.

Return On Investment

• At a retrofit cost of $1400.00 ROI may take many years(12), (water savings of $112)

• Of course rising water prices will decrease this ROI over time, but what is the cost of slip and fall liability?

• An improved irrigation design would have allowed for other options for retro-fit.

• Property management reaction was very positive. **very important if you are their contractor**

2011

• With a high distribution uniformity, it is very likely that run-times may be reduced, contributing additional water savings.

• Remember, if you are 50% efficient you need to use double the plant water requirement to fulfill water needs.

• SWS will continue to monitor and collect data from this zone.

Retro-fit # 2- Nozzle replacement-Zone 6

VS

Why Zone 6?

Potable Water Waste

Traditional Spray Heads

PM Expo

November 28, 2007.

How Property Owners are using technologyto significantly reduce their watering costs.

Examples

Retrofit Product Selection

• Rotary nozzles and pressure regulation seem like an option.

• Drip is not an option due to the existing plant material in use (turf grass).

Products Tested in Retrofit

1. Rainbird 12H sprinkler nozzles – 12” spray head. ***Products in use at time of audit***

2. Hunter MP Rotator Side Strip Series – 12” spray head.

3. Toro Precision Nozzles 12H – 12” spray head.4. Rainbird Rotary Nozzles 13-18 – 12” spray head.5. Hunter MP Rotator 1000 Series – 12” spray head.6. Rainbird U series 12H sprinkler nozzles – 12” spray

head.7. Hunter MP Rotator 1000 Series – 4” spray head.

Please Note….

• The intent of this study was not to test nozzle performance of different manufacturers against each other.

• Nozzles were selected based upon the spacing of the sprinkler heads and nozzle selection was based on what was readily available at distributor locations.

• No conclusions on overall nozzle performance are implied in the results of the study.

Hunter MP Rotator

Toro Precision Nozzles

Rainbird Rotary Nozzle

Rainbird U-Series Spray Nozzle

Audit Details

• Only sample area was catch can audited.• Zone 6 was operated for 20mins per audit.• The amount & depth of water in each catch can was

recorded.• 7 audits were performed. • 1 audit performed with existing sprinklers for

benchmarking.• 6 different irrigation products and scenarios were

tested.• Ultra-Sonic flow meter used to obtain real-time flow

(lpm) for each test.

Zone 6 with Audit Area highlighted

Detail of sprinkler layout

Layout of Catchment Area

Catch Can Layout

Water Collection To Measure Uniformity and Volume

Catch cans are drained and dried between testing products to prevent data contamination.

Collecting Data

• The amount of water in each cup was recorded in ml.• The depth of water that fell was recorded in mm.• The data was then used to establish how much water

fell on the landscape and how much fell on the parking lot.

• We used this information to establish a products precipitation rate and uniformity.

• Weather, flow & soil data were also collected.

Weather Conditions

• Weather conditions were monitored and recorded throughout the audits using Davis Vantage+ weather station.

Soil Samples

• Soil samples were taken to establish the infiltration rates of irrigation water.

• Infiltration rates determine how quickly the soil will absorb water.

• If water falls too quickly the excess will run-off into the parking lot.

• At present time we have no way of measuring excess run-off (water lost from exceeding the soil infiltration rate).

Soil & Infiltration rate

• The soil was established to be a clay loam.

• Based on documented information the infiltration rates for clay loam is approx 12mm/hr.

Densograms

• The following images give us a visual representation of where and how much water fell.

Baseline: Rainbird 12H spray nozzles

Hunter MP Rotator SST

Toro Precision Nozzles 12H

Rainbird Rotary Nozzles 13-18H

Hunter MP Rotator 1000 series

Rainbird 12UH Spray Series

Hunter MP Rotator 1000 Series • Installed on 4” spray head

Audit Data

Summary of Findings

• Significant improvement from retrofit but still a large amount of water being wasted.

• Retro-fit was simple and quick.• Currently approximately 35-50% of landscape water is being

wasted. • For a 22 week season water waste in zone 6 could equal 25m3

– 50m3• Note the pressure difference by reduction of velocity.• Old zone run-time of 20 mins per cycle was applying 13.5 mm

which exceeds the infiltration rate of the soil.

Summary of Findings

• With the exception of the final 2 tests, all of the products scored uniformity lower than 60%. The IA has commented that a system with less that 60% uniformity should not be operated.

• In the final test we replaced the 12” spray head bodies with a more appropriate 4” type (this resulted in strange data due to height of sprinklers).

• The uniformity would most likely increase on all products if they are installed on shorter spray heads.

Summary of Findings

• Even with a significant reduction in waste, the best we can hope for with this design, plant selection and installation is waste of 500L per week, 10,000 litres per year.

• Prior to upgrades water waste was 22,480 litres

• This highlights that there is no “silver bullet” for retro-fits.

• Catch can audits are not easy to do in uniquely shaped areas.

• Plant selection influences water use significantly.

Approximate Retrofit Costs

• Zone 6 = 24 heads

• 24 Nozzles at $15 ea including labour = $360.00

• Total Zone 6 Retrofit = $360.00

Return on Investment

• Water savings of $48-$95/year at $1.90/m3 (current Halton water rate).

• If we save $95 a year on a retrofit it may take 4 years to recoup investment.

• Property Management ignored the amount of years for ROI and focused on the total litres.

• We are not including unseen costs.

• Tens of thousands are spent every years on hard surface and parking lot repair due to water damage.

• Plant material is also replaced every year due to over-watering. ***Lowering precipitation rates and managing run-times reduces this.***

Other ROI Factors

• Total hours for project- 50 hours

• Challenges with wind, traffic, drip retrofit (digging).

• To audit the entire zone 6, it would take approx 4 hours per test. (28 hours continuous)

• Catch can audits during the day attract significant attention.

Project Details

Conclusions

• Removal of turf in difficult too water areas is a realistic option.

• Replace turf medians with drought tolerant perennials irrigated by drip-line or point source emission devices will eliminate waste and result in 22,000 litres NOT reaching the parking lot.

• Study highlights that installation of weather based irrigation systems needs to be paired with efficient irrigation systems to maximize water savings in landscape irrigation.

2011

• The installation of “drip” or point source irrigation combined with a landscape material change will result in a significantly reduced water requirement that will contribute further water savings.

• SWS will monitor water use in the zone moving forward.

Questions? Comments?

Thank You!