IRRIGATION WATER MANAGEMENTPLAN CRITERIA

PRACTICE/ACTIVITY CODE(118) (NO.)

1. DefinitionofanIrrigationWater ManagementPlan

TheobjectiveofIrrigation WaterManagement (IWM)is to control thevolume, frequency, and rateofwater forefficient irrigation, and forthefollowingpurposes:

  • Promotedesired cropresponse.
  • Optimizetheuseof availablewatersupplies.
  • Improvewaterquality, byreducingirrigation sources ofsurface andground water contamination.
  • Minimizeirrigation induced soil erosion.
  • Improvesoil environment forvegetativegrowth.
  • Managesalts in the rootzone.
  • Improve airquality, byreducingmovement ofparticulatematter.
  • Provide appropriateandsafefertigation and chemigation.
  • Reduce energyconsumption.

TheobjectiveofanIrrigation WaterManagementPlan (IWMP)is to providethe produceraguide forthepropermanagement andapplication ofirrigationwater resources. Thepotentialbenefits ofIWM can beeffectivelydetermined by interviewingtheproducerto identifyfields, soils, crops, climate, andavailablewater supply; measuringthevolumes ofwaterwithdrawn or applied; determining irrigation system uniformity, selectingamethod to scheduleirrigations, and then combining these components to produce anIWMPforthefarm.

2. IWMP Criteria

This section establishes theminimum criteriato be addressed in thedevelopment of

Irrigation WaterManagement Plans.

A. General Criteria:

1. Irrigation WaterManagement Plans shall bedeveloped bycertified Technical ServiceProviders(TSPs). Inaccordancewith Section 1240 (A), the Environmental Quality IncentiveProgram (EQIP)program providesfunding support throughcontractswith eligibleproducers to obtain services ofcertified TSPs fordevelopment ofIrrigation WaterManagement Plans. ThespecificTSP criteriarequiredforIrrigation WaterManagement Plan development is locatedon theTSPregistry(TechReg)web site at:

2. TheIWMPshould address the resource concerns identified, and the conservation practices needed to comprisea conservation system forIWM. In addition, theIWMPshould bebased on theeconomics ofwateruse, energyconsumption, and cropyield. Management maybelimited bywater (deficitirrigation), orlimited byland (unlimited water). Thetwogeneral management schemes forirrigation water conservation in agriculture are: Demand Management (reducing withdrawals orreducing crop requirements), andSupply Management (increasing waterstorage,yield, orsupplies).

Technologies availableforDemand Managementinclude:

• Irrigation scheduling.

• Increased system uniformity.

• Increased irrigation efficiency.

• Reduced water evaporation.

• Reduced soil evaporation (utilize crop residueormulch).

• Reduced waterusebynon-beneficial vegetation.

• Limited irrigation (applyingless than maximum ETc).

• Crop selection (lowerETcordrought resistant strains).

• Decision-makingmodels(optimizewater, energy,and nutrient use).

• Conversion ofirrigatedcropland to dryland farming.

Technologies availableforSupplyManagement include:

• Increased waterstoragecapacity.

• Groundwater recharge.

• Waterharvesting.

• Vegetativemanagementforincreased watershed runoff.

• Reuseofwasteordrainagewater.

• Watertransfers

B. IWMPTechnical Criteria. TheIWMPshould include, but not belimited to, the followingcomponents:

  1. Farm andfield information:
  2. Nameofproducer.
  3. Farm number.
  4. Field and/ortract number.
  5. Crops grown,and planned rotation byfield.
  6. Nameof contractoror consultant developingplan.
  7. Dateofplan development.
  8. Theobjectives oftheproducer, which should involveoneofthepurposeslisted in Conservation PracticeStandard (CPS)449,Irrigation WaterManagement.
  9. A map that includes fieldboundaries, andasoils map with thepredominant soils listed and areaquantified. Ifthequalifying acres forthe plan areasubset of fields, theboundaries oftheIWMPacreageshouldalso bedelineated.
  10. An irrigation system mapthat includes thesize, materials, and locations of themains, laterals, andapplication systems.
  11. Documentation ofpast waterwithdrawals and applications, bycrop.
  12. Themethods planned tomeasureorquantifyfuturewaterwithdrawals and irrigation applications.
  13. Planned waterapplication volumes, on aseasonaland/or annual basis, and bycrop.
  14. Soil tests, to includenutrient levels and salinity. Watertests, to include nutrients, pathogens, salinity, pH, and traceelements.
  15. Estimates ofirrigation system uniformity, based on testing, evaluation, or observation.Distribution Uniformity(DU)should bebased on theratio of the averagedepth infiltrated in thelow one-quarterofthe field, to the averagedepth infiltratedoverthe entire field.
  16. Documentation ofthescientificmethod planned forschedulingthetiming and amount ofirrigationapplications, based on themeasurement or estimation ofsoil moisture, and themeasurement orprediction of evapotranspiration (ETc)ofthe crop(s). Theproposed irrigation schedulingmethod should include:

a. Estimated volumeofwater applied, byfield, irrigation event, season, and/oryear.

b. Estimated frequencyortimingofirrigation applications, byfield.

c. Estimated application rates and depths ofirrigation events.

11. An Operation and Maintenanceplan, to includeacheck list ofitems to eliminatenon-beneficial system losses.

12. A signaturepage, with names, dates and signatures of all contract holders and theperson who prepared theplan. Thesignaturepageshouldalso contain aspace forapproval byNRCS.

13. TheIWMPcomponentsshall be assembled into one completeplan.

C. Associated PracticeStandards. TheIWMPshould address theresource concerns identified, and the conservation practices needed to comprisea conservation system forIWM. In addition to theinformation requiredin CPS449, Irrigation WaterManagement, existingirrigation systems and conveyance facilities mayrequiremodification, augmentation, or replacement ofcomponents. NRCS ConservationPracticeStandards to beincorporated in theIWMPcould include:

Code / Practice name
449 / Irrigation WaterManagement
441 / Irrigation System, Micro
442 / Irrigation System, Sprinkler
443 / Irrigation System, SurfaceSubsurface
430 / Irrigation Pipeline
428 / Irrigation DitchLining
388 / Irrigation Field Ditch
320 / Irrigation Canal orLateral
587 / Structure forWaterControl
436 / Irrigation Reservoir
447 / Irrigation System, TailwaterRecovery
533 / PumpingPlant
464 / IrrigationLandLeveling
450 / AnionicPolyacrylamide(PAM)Application
610 / Salinityand SodicSoil Management
590 / Nutrient Management

D. References

•USDA-NRCS, National EngineeringHandbook,Part 623, Section 15,Irrigation.

•USDA-NRCS, National EngineeringHandbook,Part 652, NationalIrrigationGuide.

3. Deliverables for theClient– a hardcopy oftheIWMP thatincludes:

• Coverpage– name, address, and phonenumberofproducer and TSP; Total Acres of thePlan, signatureblocks fortheTSP, producer,and asignatureblock fortheNRCS acceptance.

• Soils map and appropriatesoil descriptions.

• Resource assessment results (wind and watererosion, water availability, soil fertility, and others thatmaybeneeded).

  • CompleteHardcopyofthe client’s plan (MsWordcopy). Document theplannedconservation practices showing the planned amount, the fields wherethepracticeis to be applied, and theplannedyearof application.

4. Deliverables for theNRCSFieldOffice:

• CompleteHardcopyandElectronic copyofthe client’s plan (MsWord and/or other appropriate digital copies).

• Digital Conservation Plan Map with fields, features, and structural practices located.

• Digital Soils Map.

NRCS

August 2012

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