OR Well Driller key terms

A written authorization from the state granting the holder a priority-dated right to divert or withdraw a set quantity of water for a stated beneficial use, subject to conditions and later confirmation of the right.

The final document issued after a permitted use is developed and verified, confirming the perfected right, its quantity, rate, point of diversion, and priority date in the state's records.

The date a water right application was filed or the use first began, establishing the holder's rank relative to other users; earlier dates receive water first during shortages.

A doctrine under which the right to use water is based on first use and is ranked by priority date, with water diverted to beneficial use regardless of whether the land touches the stream.

A recognized, reasonable application of water that produces a benefit, such as domestic supply, irrigation, stock watering, or municipal service; failure to put water to beneficial use can forfeit the right.

A right with an earlier priority date than another right on the same source; the senior holder is satisfied first when supply is insufficient to meet all demands.

A right with a later priority date than another right on the same source; its holder may be curtailed or required to stop diverting when the senior right cannot be fully satisfied.

A regulatory order reducing or stopping diversions by junior users so that senior rights can be met during drought or low-flow conditions.

Loss of a water right, in whole or in part, for failing to apply the water to beneficial use for a specified statutory period, often several consecutive years.

Intentional and permanent relinquishment of a water right, shown by nonuse plus evidence of intent not to resume use, distinct from mere temporary inactivity.

The specific location, described by coordinates or legal description, where water is withdrawn from its source; it must match the approved permit and be marked as required.

The legally described land or service area where water may be applied under a right; using water outside it generally requires a transfer approved by the state.

A state-approved change to a right's point of diversion, place of use, purpose, or period of use, granted only if other users are not injured.

The principle that a change to a water right may not harm other rights holders; the applicant must show altered operations will not enlarge the right or reduce return flows others rely on.

Water that leaves the place of use after diversion, such as irrigation deep percolation or tailwater, and returns to the stream or aquifer where later users may depend on it.

The driller's record of a borehole showing depth, formations penetrated, casing and screen settings, grout intervals, static water level, yield, and other construction details, filed with the state as required.

The required filing submitted to the state agency after drilling, documenting the completed well's location, dimensions, materials, and testing results within the mandated deadline.

A formal record prepared by the licensed driller summarizing the work performed on a well, often required for permitting, inspection, or transfer of property.

The statutory time limit, commonly a set number of days after finishing work, within which the driller must submit the well report to the regulatory agency.

A pre-construction filing telling the water agency that a well will be drilled, giving location and proposed use so the project can be reviewed or a permit issued.

A state or local approval authorizing construction or use of a specific well, often tied to a water right, land-use approval, or setback and construction standards.

The minimum required horizontal distance between a well and a contamination source such as a septic system, sewer line, fuel tank, or property line, set by regulation.

The grouted, impermeable barrier placed in the annular space between the borehole wall and casing near the surface to prevent surface water and shallow contaminants from entering the well.

The gap between the outside of the well casing and the borehole wall, which must be filled with grout or other approved material to seal the well.

A cement-based or bentonite mixture placed in the annular space to form a permanent, low-permeability seal that blocks vertical movement of water and contaminants along the casing.

A mixture of cement and water, sometimes with approved additives, used for sealing well annuli; it is dense and provides a strong hydraulic barrier when properly placed.

The pipe installed in a borehole to hold the opening open, protect the pump, and isolate the well from unstable or contaminated formations; its material and wall thickness must meet standards.

A slotted or perforated section of casing set opposite a producing formation to admit water while holding back sand and gravel; slot size is matched to the aquifer material.

Selected, washed sand or gravel placed around a well screen to filter formation particles, stabilize the borehole, and improve flow into the well.

The engineered granular material, sized to the aquifer's grain distribution, installed between the screen and formation so fine particles are held back while water passes freely.

The depth to water in a well when the pump has been off long enough for the water level to stabilize, reflecting the surrounding aquifer's natural head.

The depth to water measured while the pump is running and the well is producing, which is lower than the static level because of drawdown.

The drop in water level in a well or aquifer caused by pumping, measured as the difference between static and pumping water levels.

The roughly cone-shaped lowering of the water table or potentiometric surface around a pumping well, which can capture water from nearby sources or wells.

Well yield per unit of drawdown, usually expressed in gallons per minute per foot; a declining value over time can signal plugging, screen damage, or aquifer decline.

The ratio of theoretical drawdown in the aquifer to actual drawdown in the well, expressed as a percentage; low efficiency points to head losses at the screen or gravel pack.

The overlapping drawdown cones of nearby pumping wells, which increases total drawdown and can reduce yield or cause one well to affect another's water level.

A controlled pumping or injection test used to estimate aquifer properties such as transmissivity and storativity, and to evaluate well performance and boundaries.

A measure of how much water an aquifer transmits through its full saturated thickness, equal to hydraulic conductivity times thickness; it governs how much a well can produce.

The volume of water an aquifer releases from or takes into storage per unit surface area per unit change in head, reflecting whether the aquifer is confined or unconfined.

A property describing how easily a porous material transmits water under a hydraulic gradient, dependent on both the medium and the fluid's properties.

A saturated layer bounded above and below by low-permeability material, so its water is under pressure and rises in a well above the top of the aquifer.

The imaginary level to which water in a confined aquifer would rise under its own pressure, shown by the static water levels in wells tapping that aquifer.

A well in a confined aquifer where the pressure head raises water above the aquifer top, and in a flowing artesian well, above land surface without pumping.

The process by which water from precipitation, streams, or irrigation percolates down and adds to an aquifer's stored water, offsetting withdrawals and discharge.

The upper surface of the saturated zone in an unconfined aquifer, where pore water pressure equals atmospheric pressure and which rises and falls with recharge and pumping.

The amount of water that can be withdrawn from an aquifer or basin over time without causing unacceptable consequences such as long-term depletion, land subsidence, or harm to senior users.

The process of surging, jetting, or pumping a new well to remove drilling fluids and fine particles and to improve flow from the formation into the screen.

Restoring a declining well's performance by mechanical or chemical treatment, such as brushing, jetting, or acidizing, to remove mineral and biological clogging.

The permanent sealing and abandonment of an unused well, using approved materials and methods to prevent contamination and loss of aquifer pressure through the borehole.

An official responsible for distributing water among rights holders according to priority and for enforcing curtailment or regulation orders within a basin or district.

A formal written notice from the regulator citing a specific violation of well construction or reporting rules and stating required corrective action and deadlines.

A regulator's directive requiring a driller or well owner to correct a violation, sometimes with penalties, stop-work requirements, or a schedule for remedial work.

Required coursework a licensed driller must complete each renewal cycle to maintain the license and stay current on construction standards, regulations, and safety practices.

The periodic process of extending a driller's license by submitting an application, fee, and proof of continuing education before the expiration date.