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Natural Resources

​​ How does the Manure Spreading Advisory (MSA) work?

The MSA is an advisory tool to help assess if predicted weather conditions are suitable for manure application. Use this tool in conjunction with your Oregon Department of Agriculture (ODA) approved Animal Waste Management Plan (AWMP) and the CAFO Permit.

Click on your farm location on the map below to receive the risk rating and application guidance for your specific area. Risk is based on the 72-hour precipitation forecast for a given area. This value best predicts the potential risk of off-site movement of manure applied to a field.

If you are still unsure if a manure application is appropriate, please use the geographic CAFO boundaries map to contact your local livestock water quality specialist.

If you are having technical challenges associated with accessing the MSA, please contact ODA.

Manure Spreading Advisory 


​​​​Legend: What do the risk assessments mean?

Low risk rating

A low risk rating means that an agronomic manure application has a low chance for a precipitation-caused runoff or leaching event to occur. 

Other low risk factors  

Include: low to medium soil moisture conditions; adequate vegetation cover if surface applying; and no ponding or water table within two feet of the surface.

High risk

A high risk rating means that an agronomic manure application has a high chance for a precipitation-caused runoff or leaching event to occur and/or impact an adjacent waterbody. 

Other high risk factors  

Include: Soils are saturated, the water table is within 24-inches of the surface and/or flowing tiles, is frozen more than one inch down, has thin vegetation (< 70% density), or high risk areas. High risk areas are swales, trenches, ditches, ponded areas, or other conduits that would channel water from the field to adjacent water way. Do not apply to high risk fields! Wait for them to become more suitable before applying. 

Please note, even if this map says your risk is low, it cannot account for every variable or condition present on your field. It is your responsibility to use your best judgment, adhere to all application guidelines outlined in your ODA approved AWMP and CAFO Permit conditions. If unsure, do not apply manure to prevent unwanted discharges. Manure application practices that cause a discharge can lead to enforcement action.

The Oregon Department of Agriculture assumes no responsibility for inappropriate manure application. Proper application is ultimately the responsibility of the operator.

Thank you to the Whatcom Conservation District​ for sharing this resource with ODA.


CAFO Geographic Boundaries

Geographic regions for CAFO Program with contact information for livestock water quality specialists. CAFO staff by area map




Christy Caldwell
Program Analyst
Phone: 503-986-4708