The Natural Environment

BACKGROUND

 

Environmental quality is a long standing and deeply felt concern of the people of Pound Ridge. It is a concern expressed in earliest times in terms of growing and grazing conditions; by later residents in terms of the attractiveness, livability, and rurality of the place and by present more sophisticated residents in terms of ecological integrity. In each case, concern has been expressed through the land use controls of the times.

These controls, leading to the proposals contained in this document date from 1957 when the Town adopted its first Comprehen­sive Plan. This Plan was the basis for the adoption of more stringent land use controls than had previously existed, primarily as a result of difficult topographic conditions and the development constraints which they im­posed.

Environmental awareness fostered the for­mation of the Conservation Advisory Council in 1968 (now the Conservation Board), and with its blessing in 1969, Pound Ridge ap­proved the first major subdivision under the provisions of Section 281 of the Town law authorizing a conservation development ap­proach. Based upon the initial success with the use of that open space and environmental preservation technique, four more major sub­divisions have since been approved under Sec­tion 281. These have resulted in the perma­nent preservation of much valuable open space and vastly improved subdivision design.

In 1969, the Town became the first com­munity in New York State to adopt fresh water wetlands protection legislation and to establish a Water Control Commission to ad­minister the Ordinance thus established.

In 1971, a second Town Plan was com­pleted. This Plan contained an open space preservation concept for Pound Ridge which has served the Town well.

Since 1973, again as a result of citizen in­terest and awareness, Pound Ridge has been the subject of extensive environmental research, funded both by the Town and private sources. In 1974, the Planning Board retained Environmental Assessment Associates (EAA) to prepare a comprehensive assessment of the Town’s surface and sub­surface water resources. This study, com­pleted in 1976, resulted in the first such Town-wide analysis conducted by any community in New York State.’ It provided Pound Ridge with a wealth of critical environmental data and a host of new insights into the Town’s en­vironmental problems. Since its publication, it has been used as a reference tool by the Planning Board and is, in fact, a cornerstone in the formulation of this publication.

In that same year, 1974, Pound Ridge United for Planning (PRUP), a private citizens group, funded and published the

Community Design Associates (CODA) study entitled, AN ECOLOGICAL EVALUA­TION, thus providing an environmental survey of the Town. Then in 1980, the PRUP publication, LAND USE THROUGH ECOLOGY (LUTE), provided a detailed analysis of ecological factors in each water­shed throughout the Town.’ In addition to providing extensive environmental data, the PRUP work has both informed and manifest­ly influenced the thrust and direction of future planning in Pound Ridge.

In addition to these extraordinary research achievements, Frederick P. Clark Associates, the Town’s Planning Consultants, have con­ducted numerous studies, analyses and reports including, A NATURAL INVEN­TORY MAPPING PROGRAM,² combining information produced by both the EAA and CODA reports and culminating in the publication of the ENVIRONMENTAL SYNTHESIS REPORT.³ All of these documents are available for review by the public at the Town House on Westchester Avenue. All have similarly been made available and have provided valuable input to the Westchester County “208” Water Quality Study and the Westchester County En­vironmental Mapping Program. They have, along with the U.S. Geological Survey and the U.S. Soil Conservation Service data, produc­ed an overall, in depth, environmental data base for the Town.

In fact, the environmental studies have pro­duced an incredible library of material which is at once complex and compelling. ‘Complex’ because of the staggering amount of scientific detail which has been produced and ‘compell­ing’ because of the increasingly urgent need to use the material collected in effective and creative new ways to achieve the environmen­tal goals necessary to the maintenance of ecological integrity.

GOALS AND OBJECTIVES⁴

 

To address this challenge, the Planning Board formed a citizens Environmental Com­mittee in 1978 for the purpose of developing goals and objectives as the basis for optimiz­ing our use of the knowledge which has been accumulated. These goals have been embrac­ed by the Planning Board and provide the ra­tionale for the proposals which follow them.

The environmental goals of this plan are as follows:

The natural carrying capacity of the land within the Town of Pound Ridge has been determined and can be substantiated by scien­tific data currently available to the Town. This measurable carrying capacity is to be the basis for determining the spatial distribution of land uses and the focus of our comprehen­sive planning in the future. To achieve this basic goal, the following specific aims are also established:

 

1.  To protect the quality and quantity of the surface and sub-surface water supply.

a.  In all future planning, consider the im­pact of each new development proposal in relation the the entire watershed of which it is a part.

b.  Minimize or prevent the entrance of new pollutants into the water supply system from both point and non-point sources.

c.  Preserve the retention capacity of the surface and sub-surface water supply systems, specifically the aquifers underlying the Town, so that Pound Ridge can continue to function as a water supply catchment area for New York City, Stamford, and Port Chester-Greenwich water systems as well as continue to supply a reliable source of drinking water for the Town’s own residents.

d.  Assure adequate supply and distribu­tion of water in the proper quantity and quality to serve the protect the Town’s vegetation and wildlife.

e.  Preserve those elements of the natural environment, such as wetlands and vegetation, which provide natural water filtration and purification while at the same time helping to meter its runoff.

f.  Develop an ongoing monitoring system to measure the type and degree of stress present in the surface and sub-surface waters of the Town.

g.  Minimize land disturbance and the in­troduction of impervious cover as a part part of the process of new develop­ment.

h.  Preserve the water retention capability of wetlands and forested areas by preventing or minimizing development upon them.

i.   Minimize soil erosion.

j.  Prevent new development in areas which are subject to flooding.

 

2.  Protect and enhance the present quality and variety of wildlife habitats in Pound Ridge.

a.  Maintain large, preferably continuous, areas of natural, undisturbed open space.

b.  Encourage the protection of “edges”, the transition zones between habitats.

c.  Protect a variety of types of wildlife habitat, such as forests, meadows, scrublands and wetlands.

d.  Protect wetlands and other sources of wildlife water supply.

e.  Protect endangered species of flora and fauna.

3.  Protect and enhance the scenic beauty, rural character and aesthetic appeal of Pound Ridge.

a.  Preserve important scenic features, in­cluding mature forests, streams, gorges, rock outcroppings, ~enic vistas, and other existing open spaces, as a part of the planned Townwide open space system.

b.  Protect buildings and sites of historic and/or architectural significance.

c.  Encourage the preservation of open space in highly visible areas such as along roadsides, ridgelines, etc.

d.  Provide for and preserve buffer areas between incompatible land uses.

4.  Protect air quality.

a.  Prevent the introduction of land uses that would have a negative impact,

either directly or indirectly on air quali­ty.

b.  Provide, to the degree practical and ap­propriate, attractive alternatives to the use of the automobile, including sidewalks in the business district, bike paths, bus transportation, etc.

c.  Minimize pollution from automobile traffic by providing an efficient and convenient system of roads and ade­quate areas for screened off-street park­ing in business districts.

5.  Prevent noise pollution.

a.  Continue to prevent the introduction of land uses that would have a negative impact, either directly or indirectly on the peace and tranquility of the Town.

b.  Establish realistic, specific noise level maximums.

6.  To encourage and expedite the use of long term renewable energy resources such as solar energy.

a.  To introduce subdivision controls which provide for adequate light and air, the accommodation of solar energy systems and equipment and access to necessary sunlight.’

7.  Provide opportunities for citizen understanding, enjoyment, and apprecia­tion of the natural environment.

a.  Continue to plan for and encourage the preservation of a continuous, linked open space system throughout the Town.

b.  Provide appropriately designed and located trails for hiking and horseback riding connecting the various major elements of the Town’s open space system.

c.  Provide appropriate areas for other recreational activities within the open space system, such as may be compati­ble with the primary goals of en­vironmental conservation and protec­tion.

 

To achieve these goals, the Plan proposes the following program.

1.  Building and development rules and

regulations will be revised to reflect the en­vironmental standards contained herein ~so that each building and/or land develop­ment proposal can be reviewed in terms of its compatibility with these environmental goals.

2.  The basic zone population and commercial development potential of the Town shall remain substantially unchanged, since it represents the approximate maximum which can safely and adequately be sup­ported within the limits of the Town’s natural resource capabilities.

3.  The use of Section 281 of the New York State Town Law will be continued where clustering improvements will aid in achiev­ing environmental purposes. By being par­ticularly mindful of the terrestial resources outlined in the CODA study, AN ECO­LOGICAL EVALUATION, possiblities for providing permanent preservation may be achieved through the use of the cluster­ing process.

4.  A water monitoring program is currently being instituted in Scotts Corners to pro­vide ample warning of impending overstress in this already fragile area. An ongoing, perhaps bi-annual sampling pro­gram to determine type and degree of stress in other areas of Town will provide an early warning system on a continuing basis. Every possible means of minimizing stress conditions will be pursued and new negative impacts on stressed areas will positively be prevented.

5.  The Town will continue to encourage the acquisition of ecologically significant pro­perties either by the Town itself or by ap­propriate non-profit agencies who can in­sure their preservation in perpetuity.

6.  A new concept incorporating soil type, degree of slope, and vegetative cover to achieve effective buffer areas will be incor­porated into the zoning code and the Land Development Regulations of the Town of Pound Ridge, and will provide the major device for environmental protection in the future.

 

 

Simply stated, the Soils-Slope-Setback For­mula’ is a method of calculating development parameters which will result in minimal negative impact on surface water quality. Since water quality is the most efficient single

measure of environmental quality, minimiz­ing the negative effects of human activity on the hydrology of Pound Ridge is the first priority of future planning stragety. Some of the stress that human activity places on water quality can be mitigated by establishing effec­tive buffer areas between the activity and ad­jacent water bodies.

Since the Soils-Slopes-Setback formula is the principle recommendation of this Plan and since it is a new proposal and, to our knowledge has not been used in the way we are proposing to use it in Pound Ridge, it is appropriate to include a somewhat detailed explanation of it at this point in the Plan.

 

 

SOILS-SLOPE-SETBACK FORMULA

 

Setbacks are certainly not new. They are part and parcel of well known development controls - 60 feet from the road; 50 feet from the side lot line; 100 feet from the stream are all expressions of the fixed setbacks with which we are familiar. What is being propos­ed here is a system of flexible setbacks from wetlands and watercourses based on a for­mula which factors the actual soil and slope conditions prevailing in the area of applica­tion. This system would not replace the pre­sent system of lot line setbacks.

The formula revolves around three com­ponents of the natural system - soils, vegetative cover and slope. Soils in this in­stance are the hydrologic soil groups defined by the Soil Conservation Service. The group designation, A, B, C, D, is an indicator of the minimum rate of infiltration obtained for a bare soil after prolonged wetting. The hydrologic soil groups are defined as follows:

A. (Low runoff potential). Soils having a high infiltration rate even when

thoroughly wetted and consisting chief­ly of deep, well to excessively drained sands or gravels.

B.  Soils having a moderate infiltration rate when thoroughly wetted and consisting chiefly of moderately deep to deep, moderately well to well drained soils with moderately fine to moderately coarse texture.

C.  Soils having a slow infiltration rate when thoroughly wetted and consisting chiefly of soils with a layer that impedes downward movement of water or soils with moderately fine to fine texture.

D.  (High runoff potential). Soils having a very slow infiltration rate when thoroughly wetted and consisting chief­ly of clay soils with a high swelling potential, soils with permanent high water table, soils with a claypan or clay layer at or near the surface, and shallow soils over nearly impervious material. (Soil Conservation Service, 1969)

The hydrologic soils groups are an expres­sion of the fact that different soils have dif­ferent abilities to absorb rainfall. Sandy soils absorb most of the rainfall that strikes them, much of the rainfall runs off of soils that are shallow in depth to bedrock (See Figure 1).

A soil’s vegetative cover also influences its ability to absorb rainfall and runoff. A dense cover of forest or meadow slows runoff, allowing it to be absorbed by the plants. A stream buffer covered with dense vegetation is more effective in absorbing runoff than a stream buffer of the same soil type with very little vegetation.

The final piece of this information is the slope of the stream buffer. Runoff on a par­ticular soil type increases in both rate and amount as slope increases. A very steep slope, thus, is not as effective a stream buffer as a gentle one (See Figure 2).

The stream setback system consists of com­pensating for the inadequacies of various soils

and degrees of slope by requiring stream buf­fers with appropriate widths. In areas where the soils are shallow and/or very steep, the stream buffers would need to be wider than in sandy, flat areas in order to be as effective in controlling runoff. The width of the stream buffers would be measured back from the stream not in an arbitrary straight line perpen­dicular to the stream but along the channels and swales draining to the stream. The width of the stream buffer would be based on the course and distance runoff actually travels before entering the stream. This distance is called the “effective distance” and is based on the actual configuration of the natural drainage system (see Figure 3).

In addition to buffering the impact of human activity on the land, particularly pro­viding protection from septic seepage, these areas of undisturbed vegetation abutting water and wetlands will play a most effective role in controlling erosion, stabilizing both

soiL and waterflow. Vegetative cover pro­duces a root network which inhibits erosion. This is particularly true on steep slopes with deep, highly erodible soils.

The importance of reducing and controlling erosion, however, is twofold. First, reducing erosion helps to maintain existing landforms. Second, controlling erosion reduces the goug­ing action associated with sediment laden streams. A stream which carries very few suspended particles has comparatively little cutting force. Introduction of suspended soil particles carried by runoff from nearby hillsides into a stream vastly increases its ero­sion capacity. The soil carried by a full flow­ing stream acts like sandpaper against its banks, widening and deepening the stream channel during flood periods, and loading its channel with stationary sediments during the next flood stage. This self perpetuating pro­cess can change a once picturesque and clean flowing stream channel into a widened, sedi­

ment choked gash through the landscape. In addition, the eroded sediments fill lakes, ponds and wetlands, speeding the succession process and reducing the holding capacity of these water bodies.

 

Woodlands also stabilize peak water flows. Woodland soils absorb and store a great deal of water, much of which is used by the trees and shrubs themselves. This double role of both utilization and storage serves to reduce stream flows during spring flood periods and to maintain them during dry spells in the sum­mer and fall. Reduction or elimination of ab­sorption capacity by removal of woodland, or paving an area, thus promotes sharp flood

peaks followed by low periods. This tendency reinforces the immediate effects of erosion which were discussed above.

Further, the corridors thus created have the potential to provide transition zones between habitats or “edges” so necessary to maintain­ing the integrity of wildlife habitats.

Thus, we look forward to general use of this formula as a major vehicle of en­vironmental protection in the immediate future. Combined with the application of ac­cepted practices such’ as use of Section 281 and with continued vigilance and attention to detail in the review procedure, we believe the Town will once again set a new standard for excellence in environmental protection.

Conclusion

The conclusion of this Plan signals the beginning of a new planning program to im­plement its principles.

We hope you, the citizens of the Town will continue to participate in that process.

In a very real sense this is your plan. Your insistence on environmental priorities is the very spine of the document. It has been refin­ed in response to your expressions of concern gathered in five public information meetings held to discuss the draft. It has been reviewed by the Town Board and modified to include their ideas wherever possible.

Now the interest and energy which produc­ed the plan must be addressed in the process of incorporating its priorities in the land use controls of the Town.

 

Adopted by resolution of the Planning Board March 19, 1981