Irrigation Land Leveling

Irrigation Land Leveling POLLUTANTS ADDRESSED: Nutrients and Organics, Salinity, Sediments

Agricultural land DESCRIPTION: Reshaping and leveling the surface of land to be irrigated allows for uniform and efficient application of surface irrigation water without significant erosion, loss of water quality, or damage to soil and crops from water logging.

ADDITIONAL BENEFITS: None POTENTIAL TREATMENT AREAS: Agricultural lands

LOAD REDUCTION MECHANISM: Nutrients/Organics Management – Leveling of irrigated lands reduces overland water flow thus reducing transport of nutrients and organics to adjacent streams.

ALTERNATIVE MANAGEMENT MEASURES: Cover Crop Irrigation Water Management Seeding

Salinity Reduction – Soil salts are not carried into adjacent waters by overland flow.

PERMITTING REQUIREMENTS: A grading permit may be required, contact county regional flood control district.

Sediment Reduction – Leveling the area to be irrigated results in a reduction in runoff, erosion, and suspended sediments in nearby surface water.

LAND USE CLASSIFICATION:

Arid Southwest BMP

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Irrigation Land Leveling POLLUTANTS ADDRESSED: Nutrients and Organics, Salinity, Sediments

Level 400: MODERATE ENGINEERING 5. Consider crops, method of irrigation, soil intake rates, field slope, irrigation stream size and resulting deep percolation and runoff when determining or evaluating length of irrigation runs.

LOAD REDUCTION POTENTIAL: LOW

MEDIUM

HIGH

6. Consider the depth of cuts and the resulting available plant rooting depths to saline soils and to shallow water tables.

ESTIMATED TIME FOR LOAD REDUCTION: IMMEDIATE

MONTHS2 YEARS

> 2 YEARS 7. In areas with sediment-laden irrigation water, consider increasing the required height of the water surface at the point of delivery.

EXPECTED MAINTENANCE: LOW

MEDIUM

8. Consider effects on irrigation efficiencies, especially on volumes and rates of runoff, infiltration, evapotranspiration and deep percolation.

HIGH

ESTIMATED COST: LOW

MEDIUM

9. Consider effects on water flows and aquifers, and the affect to other water uses and users.

HIGH

10. Consider the effects on adjacent wetlands.

PLANNING AND IMPLEMENTATION: Riparian Planting Zone: Upland Zone and Flood flows.

1. In the design consider the excavation and fill material required for or obtained from such structures as ditches, ditch pads, and roadways.

The appropriate yardage shall be included when balancing cuts and fills and determining borrow requirements.

SOURCES OF ADDITIONAL INFORMATION: USDA, Irrigation Land Leveling: Conservation Practice Standard, Irrigation Land Leveling prepared for the Natural Resources Conservation Service. http://efotg.nrcs.usda.gov/references/public/NM/464.pdf

2. Consider related structures and measures needed to control irrigation water and/or storm water runoff.

3. Consider crops, method of irrigation, soil intake rates, field slope, irrigation stream size and resulting deep percolation and runoff when determining or evaluating length of irrigation runs.

EPA; Management Measures for Agricultural Sources: Irrigation Water, 1982. http://www.epa.gov/nps/MMGI/Chapter2/ch2-2f.html.

4. Consider related structures and measures needed to control irrigation water and/or storm water runoff.

Arid Southwest BMP

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