§ 33-3-111. DESIGN STANDARDS FOR FOREST BUFFERS AND BUILDING SETBACKS.

(a)

In general.

(1)

(i)

A forest buffer for a stream system shall consist of a forested strip of land extending along both sides of a stream and its adjacent wetlands, riverine floodplain, and slopes.

(ii)

The forest buffer width shall be adjusted to include contiguous, sensitive areas, such as steep slopes or erodible soils, where development or disturbance may adversely affect water quality, streams, wetlands, or other bodies of water.

(iii)

The adjustment required under subparagraph (ii) of this paragraph shall be accomplished by evaluating the potential of a site for impacts that result from runoff, soil erosion, and sediment transport.

(2)

(i)

Except as provided in subparagraph (ii) of this paragraph, for those sites where forest vegetation does not exist, it is acceptable to allow the forest buffer to succeed naturally to a wooded state.

(ii)

If channel erosion, stream pollution, or habitat degradation exists at that site or has been caused downstream from that site, the Director may require planting of the forest buffer and any additional water quality protection measures.

(3)

The Department may post the forest buffer.

(b)

Forest buffer standards for streams, wetlands, and floodplains.

(1)

In this subsection, "stream order" is a classification system of streams based on stream hierarchy. The smaller the stream, the lower its numerical classification. A first order stream does not have tributaries and normally originates from springs, seeps, or both. At the confluence of two first order streams, a second order stream begins. A third order stream begins at the confluence of two second order streams and so on.

(2)

(i)

For a first or second order stream, the forest buffer shall be measured from the centerline.

(ii)

For all higher order streams, the forest buffer shall be measured from the stream bank of the active channel (bank-full flow).

(3)

For a surface water designated use I or I-P stream, the forest buffer shall be the greater of the following:

(i)

75 feet;

(ii)

25 feet from the outer wetland boundary; or

(iii)

25 feet from the riverine floodplain reservation or easement boundary.

(4)

For a surface water designated use III, III-P, IV or IV-P stream (natural and recreational trout waters), the forest buffer shall be the greater of the following:

(i)

100 feet;

(ii)

25 feet from the outer wetland boundary; or

(iii)

25 feet from the riverine floodplain reservation or easement boundary.

(c)

Adjusted forest buffer standards and requirements for streams and wetlands with adjacent steep slopes and erodible soils.

(1)

A steep slope and erodible soils evaluation shall be conducted in accordance with the evaluation procedures and criteria specified in this subsection or a comparable method approved by the Director for sites containing or adjacent to streams, wetlands, or other bodies of water where:

(i)

Slopes exceed 10% within 500 feet of the streams, wetlands, or bodies of water;

(ii)

Soil erodibility K values exceed .24 within 500 feet of the streams, wetlands, or bodies of water; or

(iii)

The vegetative cover type within 100 feet of the streams, wetlands, or bodies of water is: bare soil; fallow land; crops; active pasture in poor or fair condition; orchard-tree farm in poor or fair condition; brush-weeds in poor condition; or woods in poor condition.

(2)

An evaluation report shall be submitted for review to the Department, which shall include, at a minimum, the following:

(i)

A plan, at a scale not smaller than 1" = 100', that shows:

1.

Existing topography with contour intervals no greater than 5 feet (county photogrammetric maps are an acceptable source for preparing existing topography);

2.

Mapped soils as shown in the county soil survey;

3.

Field delineated, marked, and surveyed streams and wetlands;

4.

Existing vegetation;

5.

Existing subdrainage areas of the site; and

6.

Slopes in each subdrainage area segmented into sections of slopes less than or equal to 10%, 11% to 19%, and equal to or greater than 20%;

(ii)

All slope analysis data forms;

(iii)

A summary of findings including information pertinent to the evaluation of the site; and

(iv)

A mitigation plan that describes the proposed additional protective measures for those areas where development is allowed with restrictions.

(3)

(i)

The site shall be evaluated by assessing each segment of each subdrainage area using the evaluation criteria in Table 1.

(ii)

Each segment shall be given a score for slope, slope length, soil erodibility, vegetative cover type, and sediment delivery.

(iii)

A total score shall be assigned for each segment.

(iv)

A segment of a subdrainage area with a total score of 35 or greater shall be designated as part of the forest buffer and no development shall be approved in that segment.

(v)

1.

A segment with a total score of 25 or 30 shall require the application of additional protective measures.

2.

Development may not be prohibited and that area is not required to be part of the forest buffer.

(vi)

A segment with a score of 20 or less shall be developed with standard protective measures and that area is not required to be part of the forest buffer.

Table 1 Evaluation Criteria for Steep Slopes and Erodible Soils
Factors	Scores
	High (10)	Medium (5)	Low (0)
Slope (S)	S ≥ 20%	10% < S <20%	S ≥ 10%
Slope length (SL)	SL ≥ 200'	50' < SL < 200'	SL ≥ 50'
Soil erodibility (K)	K ≥ 0.32	0.24 < K< 0.32	K < 0.24
Vegetative cover type	Bare soil, fallow land, crops, active pasture in poor condition, orchard-tree farm in poor condition	Active pasture in fair condition, brush-weeds in poor condition, orchard-tree farm in fair condition, woods in poor condition	Active pasture in good condition, undisturbed meadow, brush-weeds in fair condition, orchard-tree farm in good condition, woods in fair condition
Sediment delivery (distance from downslope limit of disturbance to outer edge of wetlands or top of streambank)	Adjacent to watercourses or wetlands (<100' buffer)	Adjacent to watercourses or wetlands (100'—300' buffer)	Not adjacent to watercourses or wetlands (>300' buffer)

 

(d)

Standards for building setbacks.

(1)

At a minimum, the primary or principal structure on a parcel or lot shall be set back from the outer edge of the forest buffer as follows:

(i)

Residential dwellings, 35 feet; and

(ii)

Commercial structures and industrial structures, 25 feet.

(2)

The setback may include private land, public land, or both.

(3)

Appurtenant or accessory structures, including roads and driveways, utilities, recreational facilities, and patios, are allowed within the setback area.

(1988 Code, §§ 14-336, 14-341) (Bill No. 224, 1990, § 1, 1-1-1991; Bill No. 10-96, § 3, 3-23-1996; Bill No. 94-02, § 2, 7-1-2004)