Oregon Water Law and the Annual Reporting Requirement
Oregon operates under the Prior Appropriation doctrine — water rights are allocated in order of priority date, with senior rights taking precedence over junior rights during shortage periods. Under ORS 537.099, holders of water rights in Oregon are required to file annual water use reports with the Oregon Water Resources Department (OWRD). The reports document how much water was diverted from each source, the period of diversion, and the beneficial use the water was applied to.
The reports are due by April 1st for the prior calendar year's use. Failure to report accurately can result in forfeiture proceedings — Oregon's "use it or lose it" doctrine means water rights that go unreported may be challenged as abandoned. Conversely, over-reporting diversions (claiming more than you actually used) puts you in a weaker position during curtailment proceedings.
Accurate records matter. And until recently, most growers kept those records manually: handwritten pump hour logs, estimated flow rates, and back-of-envelope acre-foot calculations. Those methods work, but they require discipline and they're error-prone when the season gets busy.
What OWRD Wants to See
Oregon's annual water use report form (WRD 1004) asks for: the water right number, the source (stream name or well log number), the date range when water was diverted, the total volume diverted in acre-feet, and the number of irrigated acres. For ground water permits, additional information about pump depth and static water level may be required.
The total volume in acre-feet is the number most growers struggle to document accurately. An acre-foot is 325,851 gallons — roughly the amount needed to cover one acre to a depth of one foot. Converting pump run hours to acre-feet requires knowing your system's flow rate at operating head, which requires either a flow meter or a pump curve lookup combined with a pressure measurement.
OWRD's enforcement approach for small water rights (under 0.5 cubic foot per second) is relatively light — they're looking for reasonable estimates documented with some systematic method, not laboratory-grade measurements. But as Oregon's water administration becomes more data-driven, the expectation for documentation precision is gradually increasing, particularly in basins under close scrutiny like the Deschutes, Klamath, and Umatilla.
How Pump Hours Convert to Acre-Feet
The conversion from pump hours to acre-feet is straightforward once you know your pump's flow rate. The formula: Volume (acre-feet) = Flow rate (GPM) × Runtime (hours) × 60 / 325,851.
For example: a pump rated at 500 GPM that ran for a total of 420 hours during the season moved 500 × 420 × 60 / 325,851 = 38.7 acre-feet. If your water right authorizes 40 acre-feet per year, that puts you at 97% of your right — comfortably documented and within your allocation.
The flow rate input is where measurement uncertainty enters. Factory pump curves give you the rated flow at specific head conditions, but actual field performance varies with pump wear, impeller diameter, and exact head conditions. A flow meter — either a propeller meter on the discharge pipe or an ultrasonic transit-time meter clamped to the outside of the pipe — gives you direct measurement. For growers without flow meters, a pump test at the beginning of each season (measured with a bucket and timer at a sample discharge port, or via pressure-flow curves from the pump manufacturer) gives an adequate estimate.
FarmHQ's Pump Hour Logging and Export
FarmHQ logs every pump start and stop event with UTC timestamps to 1-second resolution. The dashboard provides a pump hours report by month and by date range, exportable as a CSV file. The CSV includes: event type (start/stop), timestamp, duration in minutes, and cumulative hours for the period.
For the annual OWRD report, you export the full-season pump hours (typically April 1 through October 31 for most Oregon irrigation seasons), enter your calibrated flow rate, and the Excel sheet that FarmHQ provides with the export template calculates total acre-feet and breaks the season down by month. The monthly breakdown is useful for basins where different diversion periods apply to different water rights within the same system.
The export also flags any gaps in logging — periods where the module lost cellular connectivity and events may not have been recorded. In practice, connectivity gaps are rare (most FarmHQ sites have less than 2 hours of connectivity loss per season), but the flagging allows you to note any gap-related uncertainty in your OWRD submission.
What to Do if Your Well Didn't Have a Meter
OWRD accepts pump hour-based volume estimates for wells without flow meters, provided the grower documents the basis for the flow rate estimate. Oregon's Water Resources Department has published a guidance document (available on the OWRD website) outlining acceptable estimation methods, including pump curve interpolation and correlation to similar wells in the same aquifer unit.
If you've been operating a well without a flow meter and need to establish a baseline estimate for OWRD reporting, FarmHQ's pump hour log combined with a pump curve test is an accepted method. The pump curve test involves recording system pressure at the pump discharge and using the manufacturer's pump curve for your specific impeller size to read off the corresponding flow rate. FarmHQ's pressure transducer input can log operating pressure automatically, which both validates the flow rate estimate and documents any variation across the season.
Water Rights Administration in Other Pacific Northwest States
Idaho water law (Idaho Code Title 42) similarly requires annual water use reports for diversions exceeding 13,000 gallons per day. Idaho's Department of Water Resources (IDWR) has been rolling out an electronic reporting system (eWater) since 2022. FarmHQ's CSV export format is compatible with eWater's import template, reducing the manual data entry required for Idaho filers.
Washington State manages irrigation water rights through the Department of Ecology, and annual reporting requirements vary by watershed. The Yakima Basin and the Walla Walla Basin have the most active oversight. For Washington growers, FarmHQ's pump hour reports serve the same documentation function — the specific reporting form and submission process differs by basin, but the underlying pump hour data is the same.
Planning for Tighter Compliance Requirements
Oregon's Water Resources Department is moving toward mandatory flow metering requirements for larger water rights (tentatively defined as rights above 1 cubic foot per second in priority processing basins). The Klamath Basin and the Lower Deschutes basin are likely first targets. Growers in those basins who don't currently have flow meters should start planning the installation — flow meters cost $800-2,000 installed for most agricultural well applications, and integrating the output to FarmHQ's pulse counter input produces the most accurate diversion records available without a formal USGS gauge.
The direction of water administration in the West is toward more data, more frequently reported, with less tolerance for estimated figures. Getting your measurement and reporting infrastructure in order before requirements are formalized puts you in a much better position than retrofitting under deadline. FarmHQ's pump hour logging is one piece of that infrastructure — simple to set up, automatic to operate, and already in a format that Oregon, Idaho, and Washington water agencies can accept. Questions about how to set up your season's reporting workflow? Email support@farmhq.org.