# 171.100 What are some of the terms I should know for this part?
*Annual Assessment Waiver* means a mechanism for us to waive your annual operation and maintenance assessment under certain specified circumstances.
*Annual operation and maintenance assessment* means the charges you must pay us for our costs of administration, operation, maintenance, and rehabilitation of the irrigation facility servicing your farm unit.
*Annual operation and maintenance assessment rate* means the per acre charge we establish for the irrigation facility servicing your farm unit.
*Assessable acres* (see *Total assessable acres*).
*Authorized use* means your use of water delivered by us that supports irrigated agriculture, livestock, Carriage Agreements or other uses defined by laws, regulations, treaty, compact, judicial decree, river regulatory plan, or other authority.
*BIA* means the Bureau of Indian Affairs within the United States Department of the Interior.
*Bill* means our statement to you of the assessment charges and/or fees you owe the United States for administration, operation, maintenance, rehabilitation, and/or construction of the irrigation facility servicing your farm unit.
*Carriage Agreement* means a legally binding contract we enter into:
(1) To convey third-party water through our irrigation facilities; or
(2) To convey our water through third-party facilities.
*Construction assessment* means the periodic charge we assess you to repay us the funds we used to construct our irrigation facilities serving your farm unit that are determined to be reimbursable under applicable statutes.
*Customer* means any person or entity to whom we provide irrigation service.
*Ditch* (see *Farm ditch* or *Service ditch*).
*Due date* means the date printed on your bill, 30 days after which your bill becomes past due.
*Facility* (see *Irrigation facility*).
*Farm ditch* means a ditch or canal that you own, operate, maintain, and rehabilitate.
*Farm unit* means the smallest parcel of land for which we will establish a delivery point. Farm unit size is defined in the authorizing legislation for each irrigation facility, or in the absence of such legislation, we will define the farm unit size.
*I, me, my, you*, and *your* means all interested parties, especially persons or entities to which we provide irrigation service and receive use of our irrigation facilities, such as irrigators, landowners, leasees, irrigator organizations, irrigation districts, or other entities affected by this part and our supporting policies, manuals, and handbooks.
*Idle lands* means lands that are not currently farmed because they have characteristics that limit crop production.
*Incentive Agreement* means a written agreement between you and us that allows us to waive your annual operation and maintenance assessment, when you agree to improve idle lands and we determine that it is in the best interest of our irrigation facility.
*Irrigation bill* (see *Bill*).
*Irrigation district* (see *Representative organization*).
*Irrigation facility* means all structures and appurtenant works for the delivery, diversion, and storage of irrigation water. These facilities may be referred to as projects, systems, or irrigation areas.
*Irrigation service* means the full range of services we provide customers, including but not limited to administration, operation, maintenance, and rehabilitation of our irrigation facilities.
*Irrigation water* or *water* means water we deliver through our facilities for the general purpose of irrigation and other authorized purposes.
*Irrigator* (see *Customer*).
*Landowner* means a person or entity that owns fee, tribal trust, and/or individual allotted trust lands.
*Leaching Service* means our delivery of water to you at your request for the purpose of transporting salts below the root zone of a farm unit.
*Lessee* means any person or entity that holds a lease approved by us on lands to which we provide irrigation service.
*Must* means an imperative or mandatory act or requirement.
*My land* and *your land* mean all or part of your farm unit.
*Obstruction* means anything permanent or temporary that blocks, hinders, impedes, stops or cuts off our facilities or our ability to perform the services we determine necessary to provide service to our customers.
*Organization* (see *Representative organization*).
*Past due bill* means a bill that has not been paid within 30 days of the due date stated on your bill.
*Permanently non-assessable acres (PNA)* means lands that the Secretary of the Interior has determined to be permanently non-irrigable pursuant to the standards set out in 25 U.S.C. 389b.
*Representative organization* or *organization* means a legally established organization representing your interests that confers with us on how we provide irrigation service at a particular irrigation facility.
*Service(s)* (see *Irrigation service*).
*Service area* means lands designated by us to be served by one of our irrigation facilities.
*Service ditch* means a ditch or canal which we own, administer, operate, maintain, and rehabilitate that we use to provide irrigation service to your farm unit.
*Soil salinity* means soils containing high salt content that limit crop production.
*Special assessment* means a charge to cover the uncontrolled cost arising from an urgency on an irrigation facility.
*Structures* (see *Irrigation facility*).
*Subdivision* means a farm unit that has been subdivided into smaller parcels.
*Supplemental water* means water available for delivery by our irrigation facilities beyond the quantity necessary to provide all project customers requesting water with the per-acre water duty established for that project.
*Taxpayer identifying number* means either your Social Security Number or your Employer Identification Number.
*Temporarily non-assessable acres (TNA)* means lands that the Secretary of the Interior has determined to be temporarily non-irrigable pursuant to the standards set out in 25 U.S.C. 389a.
*Total assessable acres* means the total acres of land served by one of our irrigation facilities to which we assess operation and maintenance charges. The *Total assessable acres* within the service area of an irrigation facility do not include those acres of land that are designated PNA or TNA, nor those acres of land granted an Annual Assessment Waiver.
*Trust* or *restricted land* or *land in trust* or restricted status (see definitions in 25 CFR 151.2).
*Urgency* means a situation that we have determined may adversely impact our irrigation facilities, operation, or other irrigation activities; affect public safety; or damage property or equipment.
*Wastewater* means surface runoff and subsurface drainage from your farm unit from water delivered by us that exceeds irrigation requirements.
*Water* (see *Irrigation water*).
*Water delivery* is an activity that is part of the irrigation service we provide to our customers when water is available.
*Water duty* means the amount of water, in acre-feet per acre, necessary for full-service irrigation. This value is established by decree, compact, or other legal document, or by specialized engineering studies.
*Water user* (see *Customer*).
*We*, *us*, and *our* means the United States Government, the Secretary of the Interior, BIA, and all who are authorized to represent us in matters covered under this part.