# IDAPA 20.02.01.010: Section 010. Definitions

> Idaho · Regulations · In force

URL: https://www.frixlaw.com/law-library/statutes/STATE_ID_IDAPA_20_02_01_010

## Section

- **Citation:** IDAPA 20.02.01.010
- **Heading:** Section 010. Definitions
- **Jurisdiction:** Idaho
- **Kind:** Regulations
- **Status:** In force
- **Text as of:** August 14, 2026
- **Source:** Compiled text
- **Location:** Idaho Administrative Code / IDAPA 20 (Lands, Department of) / Chapter 20.02.01 / Section 010

## Text

The terms “Best Management Practices (BMP),” “Department,” “Forest Land,” “Forest Practice,” “Forest Regions, ” “Harvesting,” “Landowner,” “Operator,” “Rules,” “State,” and “Timber Owner,” have meanings provided in Sectio n 38-1303, Idaho Code. In addition to the definitions set forth in the Act, the following definitions apply to these rules: (3-31-22) 01. Act. The Idaho Forest Practices Act, Title 38, Chapter 13, Idaho Code. (3-31-22) 02. Acceptable Tree Species. Any tree species normally marketable in the region, which are suitabl e to meet stocking requirements. Acceptable trees must be of sufficient health and vigor to assure growth and harvest. (3-31-22) 03. Additional Hazard. Debris, slashings, and forest fuel resulting from a forest practice. (3-31-22) 04. Average DBH. Average diameter in inches of trees cut or to be cut, measured at four and one-hal f (4.5) feet above mean ground level on standing trees. (3-31-22) 05. Board. The Idaho State Board of Land Commissioners or its designee. (3-31-22) 06. Buffer Strip. A protective area adjacent to an area requiring special attention or protection. (3-31-22) 07. Cable Yarding. Techniques that use winch systems, secured to stationary base machines, t o transport fully or partially suspended logs or trees to landings. (3-31-22) 08. Chemicals. Substances applied to forest lands or timber to accomplish specific purposes an d includes pesticides (as defined in Title 22, Chapter 34, Idaho Code), fertilizers, soil amendments, road dust abatemen t products and other materials that may present hazards to the environment. (3-31-22) 09. Constructed Skid Trail. A skid trail created by the deliberate cut and fill action of a dozer o r skidder blade resulting in a road-type configuration. (3-31-22) 10. Commercial Products. Saleable forest products of sufficient value to cover cost of harvest an d transportation to available markets. (3-31-22) 11. Condition of Adjoining Area
that may present hazards to the environment. (3-31-22) 09. Constructed Skid Trail. A skid trail created by the deliberate cut and fill action of a dozer o r skidder blade resulting in a road-type configuration. (3-31-22) 10. Commercial Products. Saleable forest products of sufficient value to cover cost of harvest an d transportation to available markets. (3-31-22) 11. Condition of Adjoining Area. Those fuel conditions in adjoining areas that relate to spread of fir e and to economic values of that area. (3-31-22) 12. Contaminate. To introduce into the atmosphere, soil, or water sufficient quantities of substance s that are injurious to public health, safety, or welfare; domestic, commercial, industrial, agricultural or recreational uses; or livestock, wildlife, fish or other aquatic life. (3-31-22) 13. Cross-Drain. A diversion, depression, slope, or hump in a trail or road for the purpose of carrying surface water runoff into the vegetation, duff, ditch, or other dispersion area to minimize volume and velocity o f runoff which might cause soil erosion. (3-31-22) 14. Cull. Non-marketable, live, standing trees taller than twenty (20) feet. (3-31-22) 15. Deterioration Rate. Rate of natural decomposition and compaction of fuel debris which decrease s the hazard and varies by site. (3-31-22) 16. Director. The Director of the Idaho Department of Lands or his designee. (3-31-22) 17. Emergency Forest Practice. A forest practice initiated during or immediately after a fire, flood , windthrow, earthquake, or other catastrophic event to minimize damage to forest lands, timber, or public resources. (3-31-22) 18. Fertilizers. Any substance or any combination or mixture of substances used principally as a source of plant food or soil amendment. (3-31-22) 19. Fire Trail. Access routes that are located and constructed in a manner to be useful in fire contro l efforts or fire spread deterrence in the hazard area. (3-31-22) 20. Fuel Quantity
ize damage to forest lands, timber, or public resources. (3-31-22) 18. Fertilizers. Any substance or any combination or mixture of substances used principally as a source of plant food or soil amendment. (3-31-22) 19. Fire Trail. Access routes that are located and constructed in a manner to be useful in fire contro l efforts or fire spread deterrence in the hazard area. (3-31-22) 20. Fuel Quantity. The diameter, number of stems and predominant species to be cut or already cut , and the size of the continuous thinning block, all of which determine quantity of fuel per unit of area. (3-31-22) 21. Ground-based Equipment. Mobile equipment such as trucks, tractors, dozers, skidders , excavators, loaders, mechanized harvesters and forwarders used for forest practices. (3-31-22) 22. Habitat Types. Forest land capable of producing similar plant communities at climax. (3-31-22) 23. Hazard. Any vegetative residue resulting from a forest practice which constitutes fuel. (3-31-22) 24. Hazard Offset. Improvements or a combination of practices which reduce the spread of fire and increases the ability to control fires. (3-31-22) 25. Hazard Points. The number of points assigned to certain hazardous conditions on an operating area, to actions designed to modify those conditions or to actions by the operator, timber owner or landowner to offse t those conditions on the same operating area. (3-31-22) 26. Hazard Reduction. The burning or physical reduction of slash by treatment in some manner whic h will reduce the risk from fire. (3-31-22) 27. Lake. A body of perennial standing open water, natural or human-made, larger than one (1) acre i n size. Lakes include the beds, banks or wetlands below the ordinary high water mark. Lakes do not include drainage o r irrigation ditches, farm or stock ponds, settling or gravel ponds. Any reference in these rules to Class I streams als o applies to lakes. (3-31-22) 28. Large Organic Debris (LOD)
27. Lake. A body of perennial standing open water, natural or human-made, larger than one (1) acre i n size. Lakes include the beds, banks or wetlands below the ordinary high water mark. Lakes do not include drainage o r irrigation ditches, farm or stock ponds, settling or gravel ponds. Any reference in these rules to Class I streams als o applies to lakes. (3-31-22) 28. Large Organic Debris (LOD). Live or dead trees and parts thereof that are large enough; or longe r than the channel width or twenty (20) feet; or sufficiently buried in the stream bank or bed to be stable during hig h flows. LOD creates diverse fish habitat and stable stream channels by reducing water velocity, trapping stream grave l and allowing scour pools and side channels to form. (3-31-22) 29. Noncommercial Forest Land. Habitat types not capable of producing twenty (20) cubic feet o f wood fiber per acre per year. (3-31-22) 30. Operating Area. That area where a forest practice is taking place or will take place. (3-31-22) 31. Ordinary High Water Mark. That mark on all water courses, which will be found by examinin g the beds and banks and ascertaining where the presence and action of waters are so common and usual, and so lon g continued in all ordinary years as to mark upon the soil a character distinct from that of the abutting upland, in respect to vegetation, as that condition exists on the effective date of this chapter, or as it may naturally change thereafter. (3-31-22) 32. Outstanding Resource Water. A high-quality water, such as water of national and state parks an d wildlife refuges and water of exceptional recreational or ecological significance, designated by the legislature. OR W constitutes as outstanding national or state resource that requires protection from nonpoint activities, including fores t practices, which may lower water quality. (3-31-22) 33. Prescribed Fire
g Resource Water. A high-quality water, such as water of national and state parks an d wildlife refuges and water of exceptional recreational or ecological significance, designated by the legislature. OR W constitutes as outstanding national or state resource that requires protection from nonpoint activities, including fores t practices, which may lower water quality. (3-31-22) 33. Prescribed Fire. The controlled application of fire to wildland fuels, in either their natural o r modified state, under conditions of weather, fuel moisture and soil moisture that allow the fire to be confined to a predetermined area while producing the intensity of heat and rate of spread required to meet planned objectives. (3-31-22) 34. Present Condition of Area. The amount or degree of hazard present before a thinning operatio n commences. (3-31-22) 35. Public Resource. Water, fish, wildlife, and capital improvements of the State or its politica l subdivisions. (3-31-22) 36. Reforestation. Establishment of an adequately stocked stand of trees of species acceptable to th e Department to replace those removed by harvesting or a catastrophic event on commercial forest land. (3-31-22) 37. Relative Stocking. A measure of site occupancy calculated as a ratio of actual stand density to th e biological maximum density for a given forest type. This ratio, expressed as a percentage, shows the extent to whic h trees use a plot of forestland. This term was used in the Class I tree retention rule (030.07.e.ii) and has been replace d with Weighted Tree Count as described in the same rule. (3-31-22) 38. Relief Culvert. A structure to relieve surface runoff from roadside ditches to prevent excessive volume and velocity. (3-31-22) 39. Slash. Any vegetative residue three inches (3”) or less in diameter resulting from a forest practic e or clearing of land. (3-31-22) 40. Site. An area with the combination of biotic, climatic, and soil conditions or ecological factors tha t create capacity for forest vegetation. (3-31-22) 41. Site Factor
e surface runoff from roadside ditches to prevent excessive volume and velocity. (3-31-22) 39. Slash. Any vegetative residue three inches (3”) or less in diameter resulting from a forest practic e or clearing of land. (3-31-22) 40. Site. An area with the combination of biotic, climatic, and soil conditions or ecological factors tha t create capacity for forest vegetation. (3-31-22) 41. Site Factor. A combination of average slope and predominant aspect of the operating area which relate to rate of fire spread. (3-31-22) 42. Site-Specific Best Management Practice. A BMP that is adapted to and takes account of th e specific factors influencing water quality, water quality objectives, on-site conditions, and other factors applicable t o the site where a forest practice occurs which has been approved by the Department or by the Board in consultatio n with the Department and the Forest Practices Advisory Committee. (3-31-22) 43. Size of Thinning Block. Acres of continuous fuel creating an additional hazard within an operating area. Distance between the perimeter of thinning blocks containing continuous fuel must be a minimum of six (6 ) chains apart to qualify as more than one (1) block. (3-31-22) 44. Snags. Dead, standing trees taller than twenty (20) feet. (3-31-22) 45. Soil Erosion. Movement of soils resulting from forest practices. (3-31-22) 46. Soil Stabilization. The minimizing of soil movement. (3-31-22) 47. Stream. A natural water course of perceptible extent with definite beds and banks which confine s and conducts continuously or intermittently flowing water. Definite beds are defined as having a sandy or rock y bottom which results from the scouring action of water flow. Any reference in these rules to Class I streams applies t o lakes. (3-31-22) a. Class I streams are important for the spawning, rearing or migration of fish. (3-31-22) b. Class II streams are usually headwater streams or minor drainages that are used by only a few, i f any, fish for spawning or rearing
defined as having a sandy or rock y bottom which results from the scouring action of water flow. Any reference in these rules to Class I streams applies t o lakes. (3-31-22) a. Class I streams are important for the spawning, rearing or migration of fish. (3-31-22) b. Class II streams are usually headwater streams or minor drainages that are used by only a few, i f any, fish for spawning or rearing. Where fish use is unknown, consider streams as Class II where the total upstream watershed is less than two hundred forty (240) acres in the north forest region and four hundred sixty (460) acres i n the south forest region. Their principal value lies in their influence on water quality or quantity downstream in Class I streams. (3-31-22) c. Class I Stream Protection Zone (SPZ) means the area encompassed by a slope distance of seventy- five (75) feet on each side of the ordinary high water marks. (Figure 1.) FIGURE 1 CLASS 1 STREAM PROTECTION ZONE (3-31-22) d. Class II Stream Protection Zone (SPZ) means the area encompassed by a minimum slope distanc e of thirty (30) feet on each side of the ordinary high water marks. (Figure 2.) For Class II streams that do no t contribute surface flow into Class I streams, a variance to this requirement may be requested. In no case will this width be less than five (5) feet slope distance on each side of the ordinary high water marks. Operators must provid e for soil stabilization and water filtering effects by leaving undisturbed soils in widths sufficient to prevent washing o f sediment. (3-31-22) FIGURE 2 CLASS II STREAM PROTECTION ZONE (3-31-22) 48. Time of Year of Forest Practice. Parts of a year assigned hazard points when the forest practice takes place. Points are: October through December - two (2) points; August through September - four (4) points ; January through April - seven (7) points; May through July - ten (10) points. (3-31-22) 49. Traction-Assisted Harvesting
ent. (3-31-22) FIGURE 2 CLASS II STREAM PROTECTION ZONE (3-31-22) 48. Time of Year of Forest Practice. Parts of a year assigned hazard points when the forest practice takes place. Points are: October through December - two (2) points; August through September - four (4) points ; January through April - seven (7) points; May through July - ten (10) points. (3-31-22) 49. Traction-Assisted Harvesting. Techniques that use winch systems to tether ground-base d equipment to a stationary base for stabilizing and assisting steep-slope operation. Cable tension from the winch wil l be synchronized or automatically held constant. Enhanced traction for the equipment must minimize soil disturbance and risk of sediment delivery to streams. (3-31-22) 50. Watershed Advisory Group. A formal group of citizens that provides the Idaho Department o f Environmental Quality with local public input and guidance regarding specific watersheds during watershed analysi s and BMP development. (3-31-22)

## Nearby sections

- [IDAPA 20.02.01.000 Section 000. Legal Authority](https://www.frixlaw.com/law-library/statutes/STATE_ID_IDAPA_20_02_01_000.md)
- [IDAPA 20.02.01.001 Section 001. Scope](https://www.frixlaw.com/law-library/statutes/STATE_ID_IDAPA_20_02_01_001.md)
- [IDAPA 20.02.01.010 Section 010. Definitions](https://www.frixlaw.com/law-library/statutes/STATE_ID_IDAPA_20_02_01_010.md)
- [IDAPA 20.02.01.011 Section 011. Abbreviations](https://www.frixlaw.com/law-library/statutes/STATE_ID_IDAPA_20_02_01_011.md)
- [IDAPA 20.02.01.020 Section 020. General Rules](https://www.frixlaw.com/law-library/statutes/STATE_ID_IDAPA_20_02_01_020.md)
- [IDAPA 20.02.01.030 Section 030. Timber Harvesting](https://www.frixlaw.com/law-library/statutes/STATE_ID_IDAPA_20_02_01_030.md)
- [IDAPA 20.02.01.031 Section 031. Cumulative Watershed Effects](https://www.frixlaw.com/law-library/statutes/STATE_ID_IDAPA_20_02_01_031.md)
- [IDAPA 20.02.01.040 Section 040. Road Construction, Reconstruction And Maintenance](https://www.frixlaw.com/law-library/statutes/STATE_ID_IDAPA_20_02_01_040.md)
- [IDAPA 20.02.01.050 Section 050. Residual Stocking And Reforestation](https://www.frixlaw.com/law-library/statutes/STATE_ID_IDAPA_20_02_01_050.md)
- [IDAPA 20.02.01.060 Section 060. Use Of Chemicals And Petroleum Products](https://www.frixlaw.com/law-library/statutes/STATE_ID_IDAPA_20_02_01_060.md)
- [IDAPA 20.02.01.070 Section 070. Slashing Management](https://www.frixlaw.com/law-library/statutes/STATE_ID_IDAPA_20_02_01_070.md)
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Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/STATE_ID_IDAPA_20_02_01_010. Check the current official text before relying on it. Not legal advice.