Choosing the Right Irrigation Equipment, S cheduling and Audit Requirements Kris Loomis CLIA,CID W.A Programs Specialist II Kris.Loomis@scwa.ca.gov www.sonomacountywater.org
MWELO Ordinance S ections Covered • 492.7 Irrigation Design Plan • 492.10 Irrigation Scheduling • 492.12 Audit, Scheduling and Analysis • 492.13 Efficiency
492.7 Irrigation Design Plan A to V Irrigation components and requirements a) Meters l) Minimum efficiency b) Controllers m) ASABE/ICC802-2014 c) PSI Regulators, booster n) Operating demands/restrictions d) Sensors o) Mulch = low flow e) Manual shut off valves p) Matched precipitation rates f) Backflow prevention q) Head to head coverage g) Flow sensors r) Swing joints/riser protection h) Master valves s) Check valves i) Runoff prevention t) Areas with a dimension <10’ j) Soil Infiltration rates u) 24” hardscape setback k) Hydrozones v) Slopes and application rates
Landscape Water Meters • Non-residential I’m not a meter • 1000 Sf or greater • Residential • 5000 Sf or greater Either provided by water purveyor or privately owned Courtesy of Rain Bird
S election and Installation Considerations Choose the correct meter by design flow range & minimal psi loss Courtesy of Rain Bird Follow manufacturer’s upstream and downstream installation recommendations Courtesy of Netafim Irrigation
Irrigation Controllers Must utilize data from either Evapotranspiration • Or Courtesy of Hunter Industries • Soil moisture sensing And • Non volatile memory Courtesy of Toro / Irritrol Courtesy of Rain Bird Courtesy of Rachio Courtesy of Hunter Industries Courtesy of Weathermatic
Pressure Regulation up or down If water pressure is below or exceeds the recommended psi of the irrigation devices. Too high or too low? Excess psi must be addressed by using • either a set psi or adjustable regulator Courtesy of Hunter Industries Low psi can be addressed • by installing a booster pump Courtesy of Rain Bird
S ensors • Rain • Freeze Courtesy of Hunter Industries • Wind Courtesy of Weathermatic Must be able to suspend or alter irrigation Courtesy of Rain Bird during unfavorable weather conditions Courtesy of Toro / Irritro l Courtesy of Hunter Industries
Manual S hut-off Valves Required close to point of connection • Gate IN CASE OF • Ball EMERGENCY • Butterfly Valve Can you use the valve on your backflow preventer? No!
Backflow Prevention Devices Refer to applicable local agency code for requirements Electric Double Check R.P. Device anti-siphon
Flow S ensors Have the ability to detect high flow conditions. • All commercial applications • Residential over 5000 Sf • Size by flow range • Installation considerations Courtesy of Rain Bird
Master S hut-off Valves A Love-Hate relationship • Required on all systems* • What they do • Why they do it Courtesy of Rain Bird • Problems they solve A remote valve controller may • Issues they create be your new Courtesy of Weathermatic best friend • How to get around the issues Using a quick coupler can be a challenge with master valves Courtesy of Hunter Industries Courtesy of Hunter Industries
Prevent Runoff Avoid on hardscapes, adjacent property, non irrigated areas, roadways or structures • Run-off • Overspray • Low head drainage Courtesy of WUCOLS Courtesy of Hunter Industries • What is a “similar condition”? Courtesy of Rain Bird
S oil Type and Infiltration Rates Don’t bite off more than you can chew! Soil type dictates: Water holding capacity • • Irrigation frequency Infiltration rate dictates: Courtesy of Rain Bird • How fast to apply water Maximum zone run time • • Number of cycle start times Courtesy of Rain Bird
Hydrozones Hydrozones need to be irrigated according to their unique needs Considerations • Plant type Plant factor • • Soil type • Microclimate • Irrigation method • Precipitation rates Courtesy of Hunter Industries
Irrigation Efficiency 492.13 System must be designed and installed to meet, at minimum, the irrigation efficiency…regarding the Maximum Applied Water Allowance Considerations Spray Efficiency ≥ .75 Drip Efficiency ≥ .81 Choose quality irrigation products that have: Courtesy of Netafim • In-head pressure regulation Matched precipitation rate nozzles • • Larger droplet size Pressure compensating drip emitters • Courtesy of Hunter Industries If audit proves otherwise, improvements should be made
Efficient vs. Inefficient Excessive system pressure Lack of adequate pressure Inefficient Inefficient Inefficient Efficient Efficient Efficient Larger droplet size
American National Standards Institute (ANSI) / American Society of Agricultural and Biological Engineers’/International Code Council (ASABE/ICC) Quality tested products • .65 Distribution Uniformity Lower Quarter (DULQ) or higher • Search ASABE/ICC 802-2014 on manufacturer's website • Less flexibility on equipment choices…that’s a good thing • Limited knowledge about compliant products
Operating Demands / Restrictions Operating demand considerations Pressure fluctuations due to demand • • Reclaimed water availability Restrictions # of days per week limitations • • Watering window limitations
Mulch = Low Flow The use of low volume irrigation is required to maximize water infiltration in the root zone • Drip irrigation with online emitters • Drip irrigation with inline emitter tubing
Matched Precipitation Rates Sprinkler heads and other emission devices Sprinklers…stick with one brand nozzle per zone • • Drip Irrigation…use appropriate and consistent flow • Inline …use the same flow rate per outlet per zone MPR 0 MPR 0 0 0 1 2 1 4 360 Degree = 4 GPM 0 90 degree = 1 GPM 90 degree = 1 GPM 180 degree = 2 GPM
Consistent Flow is the Key for MPR Non-Pressure compensating = less consistent flow Pressure compensating = more consistent flow Courtesy of Netafim Irrigation
Consistent Grid = Easier Calculations Calculating precipitation rate and eventually run time can be less complicated when using this method Courtesy of Netafim Irrigation
Head to Head Coverage • Goal, to achieve the highest distribution uniformity possible • Even Head to head coverage isn’t perfect • Follow manufacturer’s recommendations Poor coverage No such thing as 100% DU
S wing Joints or Other Riser Protection • Static pressure devices need higher psi rated support • Dynamic pressure devices can use lower psi rated support Courtesy of Rain Bird • Above ground options Courtesy of Hunter Industries Courtesy of Hunter Industries
Check Valves / Anti Drain Valves Check valves and/or anti drain valves are required where low head drainage may occur. They help prevent • Low head drainage • Run-off • Water hammer Courtesy of WUCOLS Courtesy of Hunter Industries • Erosion / surface problems • Water loss- guess how much? Courtesy of Rain Bird
Areas Less than 10’ = No S pray Here’s why: Short radius nozzles generally have high precipitation rates of 3” per hour +/- which soil infiltration rates can not match. Courtesy of Rain Bird Irregular shaped areas are generally less efficient and are more susceptible to runoff What to do?......
Areas Less than 10’ = No S pray What you can do: • Inline emitter tubing offers a variety of application rates to better match your soil infiltration rates. • Unusual size areas can be designed in a more efficient way. • Using a tubing with a built in check valves helps to prevent low head drainage on slopes. Courtesy of Rain Bird
24” S etback • No overhead irrigation These restrictions may be modified if: within 24” of any non- permeable surface. • The landscape area is adjacent to permeable • May include drip, dripline, or other low flow non- surfacing and no runoff occurs. spray technology. • The non-permeable • Can be planted or not surfaces are designed and planted. constructed to drain • May be mulch, gravel, or entirely to landscaping. other porous material. • An alternative is specified that must be approved and prevent runoff. Confirmed in audit.
S lopes Greater than 25% = Low Application Rate Precipitation rate cannot exceed .75 inches per hour Study manufacturer design guidelines for your soil type. Consider: • Emitter flow • Emitter spacing • Lateral spacing • Slope Precipitation Precipitation rate ok rate too high Courtesy of Netafim Irrigation Courtesy of Netafim Irrigation
Irrigation scheduling 492.10 Schedules shall be developed, managed, and evaluated to utilize the minimum amount of water required to maintain plant health. Irrigation schedules shall meet the following criteria: 1. Must have automatic irrigation controller. 2. Overhead irrigation only between 8:00 pm and 10:00* (unless weather prevents it) . 3. Scheduling should meet ETWU without exceeding MAWA. 4. Continued………..
Irrigation S cheduling Irrigation schedules shall meet the following criteria: 4. Parameters used to set controller shall be developed and submitted for each of the following: A. Plant establishment period B. The established landscape C. Temporarily irrigated areas
Recommend
More recommend
