(a) Private forest land adjacent to the following types of water and located in Region I is subject to the riparian protection standards established in this subsection:

(1) along a Type I-A water body,

(A) operations within 100 feet of the water body or to the break of the slope, whichever area is smaller, shall be conducted in compliance with slope stability standards established in regulations adopted under this chapter; and

(B) harvest of timber may not be undertaken within 66 feet of the water body;

(2) along a Type I-B water body,

(A) operations within 100 feet of the water body or to the break of the slope, whichever area is smaller, shall be conducted in compliance with slope stability standards established in regulations adopted under this chapter; and

(B) harvest of timber may not be undertaken within 66 feet of the water body or to the break of the slope, whichever area is smaller;

(3) along a Type I-C water body,

(A) operations within 100 feet of the water body or to the break of the slope, whichever area is smaller, shall be conducted in compliance with slope stability standards established in regulations adopted under this chapter; and

(B) where prudent, the operator shall retain low value timber within 25 feet of the water body or to the limit of the area described in (A) of this paragraph, whichever area is greater, where the width of the water body is

(i) greater than 13 feet at the ordinary high water mark; or

(ii) greater than eight feet at the ordinary high water mark if the channel is incised;

(4) along a Type I-D water body,

(A) operations within 50 feet of the water body or to the break of the slope, whichever area is smaller, shall be conducted in compliance with slope stability standards established in regulations adopted under this chapter; and

(B) where prudent, the operator shall retain low value timber within 25 feet of the water body or to the limit of the area described in (A) of this paragraph, whichever area is greater, where the width of the water body is

(i) greater than 13 feet at the ordinary high water mark; or

(ii) greater than eight feet at the ordinary high water mark if the channel is incised.

(b) Private forest land adjacent to the following types of water and located in Region II is subject to the riparian protection standards established in this subsection:

(1) along a Type II-A water body, harvest of timber may not be undertaken within 150 feet of the water body; additionally, harvest of timber may not be undertaken along outer bends subject to erosion within 225 feet of the water body or to the terrace top break, whichever is smaller;

(2) along a Type II-B water body, harvest of timber may not be undertaken within 150 feet of the water body; additionally, harvest of timber may not be undertaken along outer bends subject to erosion within 325 feet of the water body or to the terrace top break, whichever is smaller;

(3) along a Type II-C water body, harvest of timber may not be undertaken within 100 feet of the water body;

(4) along a Type II-D water body, there is a 100-foot riparian area; harvest of timber may not be undertaken within 50 feet of the water body;

(5) the length of the augmented buffer along an outer bend subject to erosion in (1) or (2) of this subsection must be equal to a distance eight times the stream width measured on a reach between bends at a point not widened by a point bar or channel movement; the augmented buffer must be located so that three stream widths are upstream and five stream widths are downstream of the point opposite the apex of the point bar;

(6) where an estuarine area is adjacent to an anadromous or high value resident fish water body, the riparian retention area for the adjacent water body applies to the estuarine area.

(c) Private forest land adjacent to the following types of waters and located in Region III is subject to the riparian protection standards established in this subsection:

(1) along a Type III-A water body, harvest of timber may not be undertaken within 66 feet of the water body;

(2) along a Type III-B water body, harvest of timber may not be undertaken within 33 feet of the water body; between 33 and 66 feet from the water body, up to 50 percent of standing white spruce trees having at least a nine-inch diameter at breast height may be harvested without requiring a variation;

(3) along a Type III-C water body, harvest of timber within 100 feet of the water body must be located and designed primarily to protect fish habitat and surface water quality as determined by the commissioner with due deference to the Department of Fish and Game.

(d) In this section,

(1) “low value timber” means timber that the owner or operator determines, at the time of harvest, to be uneconomic to harvest and market;

(2) “prudent” means that the requirement can be met using reasonably available means or technology, that complying with the requirement is not likely to create significant impairment of the productivity of the land and water, and that the cost of achieving the requirement is not out of proportion to the benefits that can reasonably be expected to be achieved in the particular situation.