25 C.F.R. § 171.100
What are some of the terms I should know for this part?
Cite as 25 C.F.R. § 171.100 (2025)
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.
- Cross-references to the US Code
- 25:389a.25:389b.
- Cross-references to the CFR
- 25:151.2