603-095-1940 Required Prevention and Control Measures (1) All landowners or operators conducting activities on lands in agricultural use shall be in compliance with the following criteria. A landowner or operator shall be responsible for only those violations of the following prevention and control measures caused by activities conducted on land managed by the landowner or operator. Criteria do not apply to conditions resulting from unusual weather events or other exceptional circumstances which could not have been reasonably anticipated. (2) Chemigated Irrigation Water. Effective upon rule adoption. Landowners or operators shall use the application of chemicals in combination with irrigation water in a manner that does not adversely impact waters of the state. (3) Surface Drainage and Irrigation Ditches. Effective upon rule adoption. Construction, maintenance, and use of surface drainage field ditches or surface irrigation field ditches shall cause no pollutant delivery to waters of the state from soil erosion induced by excessive channel slope, unstable channel cross section or placement of disposed spoils. (4) Erosion Prevention and Sediment Control. Effective upon rule adoption. Soil erosion rate shall not exceed five tons per acre per year between October 1 and September 30 if the resulting sediment has access to and enters the waters of the state. The erosion rate will be determined using standard scientific methods. (a) Visual on-site indicators for erosion to surface water include sheet and rill erosion that combines to a concentrated flow that runs into a waterway or road ditch, or any waters of the state. (b) Other visual indicators include sediment deposition from overland flow in channels that are carrying or connected to waters of the state. Field measurements may include depth of sheet and rill erosion on the field and by inspection of exposed roots from soil erosion. (5) Irrigation. Effective upon rule adoption. Irrigation systems shall be designed and operated to minimize runoff of potential pollutants. Irrigation scheduling shall be appropriate to each site and consideration shall be given to water use efficiency, off-target minimization, soil conditions, crop, climate and topography. (6) Waste: Livestock and Other. Effective upon rule adoption. (a) No person subject to these rules shall violate any provision of ORS 468B.025 or 468B.050. (b) Landowners and operators shall prevent the runoff or leaching of contaminated water from feed and manure storage piles into waters of the state, including but not limited to groundwater. (7) Nutrients. Effective upon rule adoption. Landowners or operators shall use and apply crop nutrients in a manner that prevents transport into the waters of the state. (8) Riparian Management Area. Effective upon rule adoption. (a) A Riparian Management Area (RMA) that allows for the natural or managed development of riparian vegetation and riparian function over time shall be provided along all streams. This shall include the natural or managed establishment and maintenance of riparian vegetation, such as grasses, sedges, shrubs, and trees, appropriate to site capability, and that in the normal course of time will provide shade and protect streambank stability from flows at or below those expected to occur during or following a 25-year, 24 hour storm event. (b) Sufficient RMA width will be site specific, and may vary by, for example, soil type, size of stream, and agricultural use. (9) Roads and Staging Areas. Effective upon rule adoption. (a) Roadways, staging areas, and heavy use areas shall be constructed and maintained to prevent sediment or runoff contaminants from adversely affecting waters of the state. (b) Exemptions: Public roads and roads subject to the Oregon Forest Practices Act. Statutory/Other Authority: ORS 561.190 - 561.191 & 568.912 Statutes/Other Implemented: ORS 568.900 - 568.933 History: DOA 50-2026, minor correction filed 02/25/2026, effective 02/25/2026 DOA 3-2002, f. & cert. ef. 1-18-02