Baltimore County, MD

Environmental Protection and Resource Management

ENVIRONMENTAL PROTECTION AND RESOURCE MANAGEMENT ' 14-341

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(a) General requirements.

(1) 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, floodplain, and slopes. 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 waterbodies. This adjustment shall be accomplished by evaluating the potential of a site for impacts that result from runoff, soil erosion, and sediment transport.

(2) For those sites where forest vegetation does not exist, it is acceptable to allow the forest buffer to succeed naturally to a wooded state. However, 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 f7oodplains.

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

(2) For a use I or I-P stream, the forest buffer shall be the greater of the following:

a. Seventy-five (75) feet,

b. Twenty-five (25) feet from the outer wetland boundary, or

c. Twenty-five (25) feet from the one hundred-year floodplain reservation or easement boundary.

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

a. One hundred (100) feet,

b. Twenty-five (25) feet from the outer wetland boundary, or

c. Twenty-five (25) feet from the one hundred-year 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 herein or a comparable method approved by the director for sites containing or adjacent to streams, wetlands, or other waterbodies where:

a. Slopes exceed ten (10) percent within five hundred (500) feet of the streams, wetlands, or waterbodies;

b. Soil erodibility K values exceed .24 within five hundred (500) feet of the streams, wetlands, or waterbodies; or

c. The vegetative cover within one hundred (100) feet of the streams, wetlands, or waterbodies 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. This report shall include, as a minimum, the following:

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

1. Existing topography with contour intervals no greater than five (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 ten (10) percent;  eleven (11) to nineteen (19) percent; and greater than or equal to twenty (20) percent;

b. All slope analysis data forms;

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

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

(3) The site shall be evaluated by assessing each segment of each subdrainage area using the evaluation criteria in Table 1. Each segment shall be given a score for slope, slope length, soil erodibility, vegetative cover, and sediment delivery. A total score shall be assigned for each segment. A segment of a subdrainage area with a total score of thirty-Five (35) or greater shall be designated as part of the forest buffer and no development shall be approved in that segment. A segment with a total score of twenty-five (25) or thirty (30) shall require the application of additional protective measures; however, development shall not be prohibited and that area shall not be part of the forest buffer. A segment with a score of twenty (20) or less shall be developed with standard protective measures and that area shall not be part of the forest buffer.

Table 1: Evaluation Criteria for Steep Slopes and Erodible Soils
Factor:	Scores
	High (10)	Medium (5)	Low (0)
Slope (S) Slope length (SL) Soil erodibility (K) Vegetative cover	S > 20% SL > 200 K> 0.32 Bare soil, fallow land, crops, active pasture in poor condition, orchard-tree farm in poor condition	10% <S < 20% 50'<SL< 200 0.24<K< 0.32 Active pasture in fair condition, brush-weeds in poor condition, orchard-tree farm in fair condition, woods in poor condition	S > 10% SL < 50' K< 0.24 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 (<600' buffer)	Adjacent to watercourses or wetlands (100' - 300' buffer)	Not adjacent to watercourses or wetlands (>300' buffer)

Figure 1: Stream Order Heirarchy

Figure 2: Stream Buffer

Figure 3: Wetland Buffer

Figure 4: Floodplain Buffer

Figure 5: Buffer Expansion for Steep Slopes