Irrigation Water Management

Irrigation Water Management POLLUTANTS ADDRESSED: Nutrients and Organics, Salinity, Sediments

DESCRIPTION: Irrigation water management is the process of determining and controlling the volume, frequency, and application rate of irrigation water in a planned, efficient manner.

LOAD REDUCTION MECHANISM: Nutrients/Organics Management- Appropriate water management will apply water at rates that minimize transport of nutrients and chemicals to surface waters and ground water.

Salinity Reduction- Appropriate water management will apply water at rates that minimize transport of dissolved salts to surface waters and ground water.

Sediment Reduction – Appropriate water management will apply water at rates that minimize erosion and transport of sediments to surface waters.

LAND USE CLASSIFICATION: Agricultural lands ADDITIONAL BENEFITS: Irrigation water management can result in reduced water costs, reduced water loss through evaporation, and soil conservation.

Arid Southwest BMP

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POTENTIAL TREATMENT AREAS: Agricultural lands ALTERNATIVE MANAGEMENT MEASURES: Cover Crop Mulching Nutrient Management Seeding PERMITTING REQUIREMENTS: Contact county regional flood control district.

Irrigation Water Management POLLUTANTS ADDRESSED: Nutrients and Organics, Salinity, Sediments

Level 100: PASSIVE MANAGEMENT LOAD REDUCTION POTENTIAL: LOW

MEDIUM

8. Consider effects of irrigation water on wetlands, water related wildlife habitats, riparian areas, cultural resources, and recreation opportunities.

HIGH

9. Management of nutrients and pesticides.

ESTIMATED TIME FOR LOAD REDUCTION: IMMEDIATE

MONTHS2 YEARS

10. Schedule salt leaching events to coincide with low residual soil nutrients and pesticides.

> 2 YEARS

11. Water should be managed in such a manner as to not drift or come in direct contact with surrounding electrical lines, supplies, devices, controls, or components that would cause shorts in the same or the creation of an electrical safety hazard to humans or animals.

EXPECTED MAINTENANCE: ď€ LOW

MEDIUM

HIGH

ESTIMATED COST: LOW

MEDIUM

12. Consideration must be given to electrical load control/ interruptible power schedules, repair and maintenance downtime, and harvest downtime.

HIGH

PLANNING AND IMPLEMENTATION: 13. Consider improving the irrigation system to increase distribution uniformity of irrigation water application.

1. Consideration should be given to managing precipitation effectiveness, crop residues, and reducing system losses.

Riparian Planting Zone: Upland Zone and Flood flows 2. Modify plant populations, crop and variety selection, and irrigated acres to match available or anticipated water supplies.

3. Consider potential for spray drift and odors when applying agricultural and municipal waste water.

4. Equipment modifications or soil amendments such as polyacrylamides and mulches should be considered to decrease erosion.

5. Consider the quality of water and the potential impact to crop quality and plant development.

6. Quality of irrigation water should be considered relative to its potential effect on the soil's physical and chemical properties, such as soil crusting, pH, permeability, salinity, and structure.

7. Avoid traffic on wet soils to reduce compaction.

Arid Southwest BMP

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SOURCES OF ADDITIONAL INFORMATION: Farm Water Quality Management Practice, Irrigation Systems, Sprinkler, #442, prepared by the University of California Cooperative Extension, Natural Resources Conservation Service. http://extension.oregonstate.edu/catalog/html/pnw/pnw2 90/