Coastal zone land use capability analysis

[From the U.S. Government Printing Office, www.gpo.gov]

A-Z

Coastal Zone COASTAL ZONE LAND USE CAPABILITY ANALYSIS
Information
center

by
Strafford Rockingham Regional Council

Property of CSC Library

U.S. DEPARTMENT OF COMMERCE NOAA
COASTAL SERVICES CENTER
2234 SOUTH HOBSON AVENUE
CHARLESTON, SC 29405-2413

This report was financed in part by the Coastal Zone
Management Act of 1972, administered by the Office
.of Coastal Zone Management, National Oceanic and
Atmospheric Administration.

September, 1976

HD
211
.N4
C6
1976

INTRODUCTION

The following section deals with the land-related resources for the coastal

zone of New Hampshire. It fulfills in part the relevant sections, Paragraph
B of the FY 175 CZM Contract, and (CZM PAR 923, 12 (a)
0@1

TERMINOLOGY

Before a discussion of land use capability begins, it will be helpful

to clarify some of the terminology employed. The CZM Act uses the terms

I'capability" and "suitability". The semantic arguments over the differences

between these two terms is enough to make Joyce's Ulysses read like a fairy

tale. In that the Act clearly represents an application of the environmental

planning method, the term "suitability," is probably most appropriate. The word

has become "such a part of the jargon of environmental planning that suggesting
an alternative seems counterproductive". (Brandes, 1973.) Because of the confu-

sion raised by the Act and the concern of OCP over the Use of these terms, a

definition of each, as used in the subsequent discussions, follows:

Capability the ability of a given natural resource or set of resources on

a given geographic site to sustain urban development.

Suitability the ability of a specific geographic site to sustain urban

development based on site "capability" as well as such factors

as water/sewer, highway access, and socio-economic demand.

The term development and urban development are used interchangeably to

apply to those uses requiring significant physical alterations to coastal lands
These uses might include, but not be limited to: residential, commercial,

industrial, and commercial-recreational,construction.

The term "natural factor" will refer to a feature such as slope, soil

conditions, or groundwater. The term natural factor "category" or "character-

istic" will be used interchangeably to refer to a particular type of natural

factor such as "0-8% slope" or "sand and gravel" soils. The t6rm natural

11resource" is synonymous with both natural factor (eg., "groundwater") and

natural characteristic (eg., "aquifer/aquifer recharge areas"). It was used

where it was deemed appropriate to the discussion, but not intended to confuse

the reader.

METHODOLOGY

As part of the procedure for "defining permissable land and water uses

within the coastal zone which have a direct and significant impact upon the
coastal waters" (CZM PAR 923 (a) ) both an "inventory" and "analysis" of the

various land-related "natural and man-made--coastal resources-1.1 was -undertaken-
(CZM PAR 923, 12 (a)_.(2)__)._ The-aim-of this effort was to determine the "capa--
bility and suitability for each type of resource and application to all existing,
projected or potential uses". (CZM PAR 923, 12 (a) (3) ).

If there is one overriding objective in the Coastal Zone Management Act,

it must be the protection of coastal waters from the impacts of urbanization.

The process of urbanization brings with it several changes or processes that

may have major impacts on coastal water resources. On construction sites the

removal of vegetation and the protective humus layer increases natural erosion

and results in greater stream sedimentation. Sediment in streams promotes

such biological and physical problems as"noted in Figure 1.

[REMOVAL OF VEGETATION & EARTHMOVING DURING CONSTRUCTION1
T
KOIL EROSIONI
ISEDIMENTS IN STREAMS & RIVERS

DETERIORATION OF SILTATION OF RIVERS, HARBORS & RESERVOIRS
STREAM HEALTH] IREDUCTION IN FLOOD CAPACITY OF RIVER CHANNELS

Figure 1. Source: Tourbier, 1973

-2-

(See Tourbier for a more detailed discussion of this problem,)

A second major change is the increase in such impermeable surfaces as roads

and parking lots that enhancesrunoff and reduces infiltration of water into the

ground. The increased runoff is also of greater velocity, which tends to in-

crease the vo lume and frequency of floods. This runoff also carries additional

contaminants from automobiles, etc. that reduce water quality. The decrease

In groundwater recharge means a lowering of the water table. This problem

becomes crUcial,during periods of dry weather when groundwater aquifers feed

streams. Lower stream flows decrease the assimilative capacity of coastal
waters, thus resulting in degradation of water quality. (S@e Figur e"2.)

[INCREASE IN AREA OF IMPERMEABLE, PAVED SURFACESI
f- T_ --Ile
JINCREASED RUNOF_ FR_EDUCED INFILTRATION1
[
INCREASE INI INCREASE IN FLOOD VOLUME REDUCTION IN DRY REDUCTION IN YIELD FROM]
EROSION & INCREASE IN AREA.-OF' 11WEATHER S REAM FLOW] UNDERGROUND WATER
FLOODPLAINS

Figure 2. Source-:- Tourbier.- 1973--

The'third change that occurs from urbanization is the addition of In creased

waste load to coastal waters from faulty.septic tanks (or leakage from sewer
systems) or improperly-located septic tanks. For instance, a site may be

inadequate to handle the septic effluent because of poor drainage. Although

malfunctioning sy stems are not directly attributable to urbanization, it is a

long-term problem that can be of great significance in the management of..the

coastal zone. (S ee Figure 3.)

I_FAILURE.__.OF SEPT ICJAN.@Sj
JINSTALLATION OF SEWER SYSTEMI

LEAKAGE OF DISCHARGE OF EFFLUE
SEWER LINES1 ISEWAGE TREATMENT
4-
ISTREAM & GROUNDWATER POLLUTION
Figure 3. Source: Tourbier,19731
-3-

In considering a model for evaluating the various coastal resources for

their ability to accommodate future growth, substantial consideration was given
to the objective of minimizing the impacts of the above changes. Jn eff ect, this.

approach relies heavily on the concept of land capability for protection of
coastal waters. This approach or model (as well as most other capability models)

employs the-proposition that the natural environment should significantly deter-

mine future land use. Further, by analyzing and understanding coastal natural

resources one can determine not only the best places to develop, but also the

best places not to develop. The model relies heavily on the protection of

water.resources by minimizing the impacts of urbanization. For example, fresh-

water and tidal wetlands are not suited to development. Increased flooding,and.
decreased water stbr@a�e-, .and -f il-teiring- c-apa'61-ty-6re- among the -adverse impacts

on coastal waters that result from wetland development. Clearly, such a valuable
resource was given high Val-tie-for"--p'rotect Ion-a nd a lowIvalue for urbanization.

Although the "state of the art" in land use planning can employ rather

sophisticated models and methods for determining land use capability, such

methods require large inputs of time, money, and relevant data. Since such

luxuries were not available to OCP or the Strafford-Rockingham Regional Council,

a more simplistic, though nonetheless valid approach to land use capability was

utilized.

The land use capability model can conceptually be br6-ken down into four
parts: (1) Inventory,. (2) Analysis, (3) Evaluation, and (4) Classification.

However, for the purposes of this discussion, the first three steps will be
included subsequently within each section of'the relevant natural factor

considered in the capability analysis. These four steps are briefly discussed

below. The Classification step Is discussed at the end of this section.

INVENTORY

In this step all relevant natural.:Eactor data and m an-made features are

collected and mapped. Each factor was broken down into appropriate map cate-

-4-

gories. For example, the slope Map contained the following categories;
(1 ) 0-8%, (2) 8-15% (3) 15-25% and (4) > 25%. Most of the Information for

the inventory is derived from.published sources. For some of the data, however,

field investigations were necessary to supplement existing information. The

detailed inventory for land-based natural factors was conducted only in the
primary and sec ondary coastal communities (as defined per section 2A of the
FY 175 Contract). The data were mapped at a scale of one inch equals 2000

feet using all or parts of the ap propriate coastal zone 7k-minute'U.S.G.S.

quadrangle maps as base maps.. The following chart shows the natural factor

maps that were completed for each quadrangle. For mapping purposes the rele-

vant portions of the Newburyport East, Mass.. Quadrangle was combined with the

Hampton, New Hampshire Quadrangle; and the Kittery and Isles of Shoals, New

.Hampshire Quadrangles were combined.

Paper print maps were used for the Newmarket and Hampton Quadrangles.

All other maps were on mylar overlays, except the "Areas of Particular Concern

Maps". These were also put on paper prints, because It was much less confusing

than using mylars.

ANALYSIS

Once the data were gatherdd@and mapped,,they were analyzed to gain a full

understanding of the various coastal resources. For Instance, wetland soils

were discovered to be poorly drained and to act as natural sponges during periods

of high runoff, thereby preventing excessive flooding. These facts by themselves

had important implications for land use capability.

However, it was soon discovered that consideration of individual natural

factors.and natural factor categories in isolation was not wholly appropriate.

It was not good'enough to know just that a particular soil was poorly drained

or well drained. Although such characteristics have implications for develop-

ment by themselves, they become more significant when considered with factors

-5-

like slope, vegetation, and nearness to water bodies. When these factors are

considered together, a better understanding of coastal ecotystems and natural

processes can be achieved. This approach also has value because it leads to

appropriate land use capability classifications and definition of "permissible

land uses".

The Coastal Zone Management Act requires a definition of permissible land

uses based upon their impact on coastal waters. In order to assess such impacts

a more holistic natural resource analysis was decided upon. If marine estuarine

organisms depend on the natural cycle of nutrient flow from upstream waters and

land areas, any significant alteration of these areas will have a decided Impact

on the nutrient flow and thus, the marine habitat. It was crucial then to

understand the coas tal area as a set of resources interacting over time and

space.

EVALUATION

Once the natural factors were fully analyzed, they were evaluated indi-

vidually for their ability to support general urban development. The "values"

attached to the various categories or characteristics of each natural factor
were subjective in nature based upon: (1) adopted plans and policies of the

coastal zone communities a-h.0-the coastal regional planning commissions (ie.,

Preliminary Comprehensive Land Use Plan for Substat e District # 6 (2) state

land use policies.as expressed in the statutes, such as the Dredge and Fill
Act, RSA 483-A, and (3) the best reasoned judgement of the planners at the

Strafford-Rockingham Regional Council. These judgements were based upon the

following criteria with assistance from expert natural scientists including
hydrologists, geologists, and soil scientists:
(1) Potential %_0_st_-saV_ings" if area we-re developed
(2) Presence or absence of physical limitations to development
(3) Whether the resource was a potential "area of particular concern"
(See discussion on areas of particular concern)

-6-

(4) Potential unreasonable environmental Impact if resources were developed.

For example, both the Land Use Plan for Substate District'# 6 and the
Southern Strafford Environmental Study encourage the preservation of-wetlands as

adopted policies of the respective commissions. The state has also recognized

the value of these ecoiystems through RSA 483-A which seeks to protect wetlands

from uncontrolled alteration through a permit process. Numerous Individual

communities (le. Durham, Rye) have addressed the problem of wetland protection
by establishing wetlands protecti-on districts.

Thus the evaluation of soils took into consideration the above as well

as other information provided by the Soil Conservation Service. Clearly, soils

with high bedrock present greater limitations to development than deep, well-

7
drained soils. The latter soils irepreferable* for urb--an-development- and'

were rated more highly for this purpose. Assigning values to specific natural

factor categories can be done'using a relative or numerical scoring system as

illustrated below for the soils under discussion.

Relative Numerical S-E
0 CL
4__ 0
CD r- -
'Wetland soils (poorly drained) low 0 CV
>
High bedrock soils medium 5

to S_
Well-drained soils high 10

For purposes of this study the soils were [email protected] on a relative basis.

A further elaboration of the ranking process is found in the Soils section.

The initial evaluation sorted out various natural features into general

capability groupings based on their ability to sustain urban development. For

instance, 0-8% slopes are more capable of sustaining development than 15-25%

slopes. The subsequent discussions for each natural factor makes the specific

evaluations clearer. This evaTuation represents-the initial-step-ih-determihing

geographic "areas of particular concern", permissible uses and determination of

priority uses in the coastal zone. For instance, such areas as lakes, coastal

wetlands, and aquifer/aquifer recharge because of their inherent vulnerability

-7-

to man's Intrusions become potential "areas of particular concern". On the

other hand,better drained, more gently sloping sites are more appropriate for

residential, commercial, or industrial uses.

CLASSIFICATION

The formulation of land use capability classes - which translate to more

specific areas on the base maps - is based upon the specific values deriVed from

the above procedure. Natural resources that have value for man when left un-
developed (wetlands, etc.) become areas of resource protection, generally analp-
gous to areas of particular concern. (The latter includes areas other than

just valuable natural resources. For example, areas that represent unusual
economic opportunity may also be-cons.,idered.) Areas that are more capable of

development, are ranked according to their ability to sustain development.

The subsequent section will discuss the Inventory, analysis, and evaluation

of each of the relevant natural factors in more detail. This will be followed

by a discussion of the capability classification system and how the various
classes or areas can be related to appropriate coastal zone land uses. (See
discussion of Permissible Land Uses).

INVENTORY, ANALYSIS AND EVALUATION

TOPOGRAPHY

The coastal zone lies geographically in what has been called the Seaboard
Lowland section of the New England Physiographic province (Fenneman, 1938).

Elevations range from sea level-to about 200 feet-for most of the area. The

highest point in the region is Hicks Hill in Madbury -- 320 feet.

The undulating topography of the coastal region generally conforms to the

underlying ledge or bedrock, although."a number of the hills are composed of

glacial deposits. The features of greatest relief are generally the rock-cored

hills, such as Great Hill In Newmarket. The other hills are of glacial origin

such as Garrison Hill in Dover which is geologically known as a drumlin (a

massive deposit of glacial till). Many of the flat sites and river valleys con-

tain swamps and wetland areas. Much of Rye and Durham Point are covered by these

wet areas. The wetlands are often flanked by glacial terraces or outwash plains

that tend to be very sandy,and flat,,and are anywhere from 30 to 80 feet higher

than the low areas.

It is important to evaluate the topography of the coastal zone, because
it provides.much of the'aesthetic quality that makes the area so unique'. Since
there are so few areas of relatively high relief, these become a visual asset.

In addition to being the most v.isi ble.elements in theIan scape, these-prq _ijqences

provide long-views. The scenic and recreational value is of both local and re ional
-9

significance. These values are expressed as adopted policies In both the Substate

#6 report and the Southern Strafford Study which encourage preservation of higher

hills and hilltops.
A number of hills were considered as areas-of resource protection.(see,-
Classification discussion following) and as potential "areas of,particular con-
cern". These hills were chosen on the basis 0@ their relative relief. They

had to provide unobstruc ted views of their surroundings and/or be features which

provided prominent observable relief from their surroundings. Specific decisions

were based on contour map Investigation and field observation using these criteria.

EARTH MATERIALS

An investigation of earth materials is important for understanding and

evaluating their potential for numerous uses such as water supply, agriculture

residential development, and mineral excav ation. For purposes of the Coastal

Zone resource inventory only surficial deposits -- those unconsolidated material

overlying the ledge or bedrock -- and soils -- the layer of material that extends

-9-

from the earth's surface to 3-4 feet -- are b6ing considered. Although the

ledge or bedrock is an Important element of earth materials, it is not of major

V
alue in coastal zone planning and will be treated only when it becomes signifi-

cant to other natural factors, ie., soils.

Surficial Geology

The surficial geology investigation relied heavily on the work of Edward
Bradley (1964). Although his studies were somewhat limited, they are the most
definitive geologic work done in coastal New Hampshire. 502)

The surficial materials which contribute much to the present day landscapetv>
of New Hampshire's coastal area are primarily the result of the last of four

continental glaciers, that occurred more than 10,000 years ago. This glacier

was a mass of ice about one mile thick which advaqced across New Hampshire from

the northwest, then melted and retreated. As it moved across the earth's sur-

face, It deposited a layer of poorly-sorted debris called till. This material

is made up of a mixture of sand, silt, clay, gravel, and boulders and is

usually 15 to 40 feet thick.

As the glacier began to melt and retreat, debris from the Ice was trans-

ported and deposited in a seemingly random fashion. (See the Surficial Geology
Maps). The sand and gravel deposits (ice-contact) are among the more common

surficial materials which were la id down close to the melting ice. They consist

of the stratified-sands, gravel, and boulders, and vary in thickness to a

maximum of 190 feet. Pudding Hill in Madbury serves as an excellent example

of such a deposit. These materials are relatively coarse since there was

little sorting by the meltwater.

Similar to the coarse sands and gravels, are the outwash sands and fine
gravels (outwash). These types of deposits, were better sorted by the meltwater

and thus are made up of finer particles than the sands and gravels. Closely

associated with the outwash are the sandy shore deposits that formed along

shorelines of an ancient sea, which occurred during the latter stages of the

-In-

glacial period. Both these deposits range in thickness from one to fifty feet
and usually occur as broad sand plains as in central Seabrook. These deposits

are combined into one category on the Surficial Geology Map -- Outwash and Shore

Deposits.

As the ice sheet continued to retreat, the great quantity of meltwater

combined with the then ancient sea to create a sea level which extended about

fifteen to twenty miles inland from the present sea level. Fine sand, silt,

and clay were deposited to a maximum thickness of 75 feet. These marine clays

are recognized by their blue-gray color

Marine clays are generally poorly drained and in many Instances highly

unstable particularly when wet. And while they may hold a lot of water, they
do not easily transmit it (-low permeability). Thus, these deposits are generally

unsuitable for wells, building sites with septic tanks, and heavy loads.

The surficial deposits have remained much today as they did after the

retreat of the glacier and the lowering of the ancient sea to its present level.

The only surficial materials that have accumulated recently are the locally
poorly drained swamp deposits-i-n.11o.w-lyi-ng_areas and alluvium.that has been de-
posited along streams.

Because of their excellent drainage and high permeability the sand and

gravel deposits often provide excellent building sites. They also have a high

bearing capacity and are easily excavated. However, there are competing

demands for these resources. Because of drainage and load-bearing characteristics

they also make excellent fill for highways, etc. The pressure to excavate these

deposits is enormous. In addition, some of these deposits can hold large
quantities of water (called aquifers); enough In some instances to provide the

source of municipal water supplies, such as Dover. It is quite clear that a
rational policy of land use regulation be ado.pted for.the more valuable sands
and gravels in order to avoid contamination of groundwater supplies.

In order to satisfy the competing demands for this resource, a multiple-
use policy should be adopted. Initially this would include a detailed hydrologic

study of the coastal area to determine the best sources of water, including both

ground and surface water. Once this has been completed, regulations can be

adopted to protect the most valuable aquifers while the other sand and gravel

deposits can be used for development and excavation.

The valuable sand and gravel deposits were identified on the Areas of

Particular Concern Map. The critical aquifer/aquifer recharge sands and gravels

were also identified as areas-of particular concern on this map. These areas are

further discussed in the groundwater section of the Inventory. Where geologic

sands and gravels coincide with sand and gravel soils, they become identified

as areas more capable of development. These areas are dealt with more specifi-

cally-in the soils section of the Inventory and the land use suitability section

of the classifica-tion di.scuss-ion.

Soils

Soils form the upper organic layer of earth materials which have developed

from the interaction of climate, vegetation, slope, and surficial geology. The

present characteristics of each,soll type are highly dependent on-its position

in one of the major sufricial- deposits.- For example, the--Hinckley and Windsor
soils are located in the level portions of sand and gravel deposits. (See

Figure 1.)

The soil conditions maps are interpreted from the Strafford and Rockingham

County Soil Surveys, since communities from both counties are within the primary

and secondary coastal zone. Although all the inventory maps have essentially

the same soil categories, the Strafford County section of the region has generally

more accurate and reliable information. This is due to the fact that the 1959

Rockingham County Soil Survey was done for agricultural pruposes and with less

accuracy control. -The Strafford County Survey was completed in 1 973 and the

soils interpretations were done for a variety of uses includ Ing suitability

for community development, forestry, wildlife, and recreation as well as agri-
culture. For purposes of the inventory and land capability mapping, the existing

-12-

-HINC(LEY

WIIIDSO

pill
7
YY.
Jef
LA Z@
L@ 1.4 P. GP@AVEL-

Figure 4. Typical pattern of soils and underlying material in the
Hinckley-Windsor-Saugatuck association.

Source; S.C.S., Soil Survey of Strafford County,
New Hampshire, 1973

soil information was considered to be of equal value. However, it must be em-

phatically stressed that the soil information and capabi-lity analysis is much

more accurate and defensible in Strafford County than in Rockingham County. The

Soil Conservation Service will legally stand behind the Strafford County Soil

Survey, but not the Rockingham Survey.

Soil conditions are a major factor In determining suitable locations for
such urban uses as residential development and recreation. Below is a des..cr.i.ption
of each soil condition category with suggested recommendations for potential

develo pment. The formulation of these soil categories and their appropriate

ranking were based in part up on the advice and values expressed by the Soil

Conservation Service. Although.S.C.S. will not legally stand behi,nd these cate-

gories for management purposes, the staff of the Couhcil feels strongly that the

rank ordering developed bel ow is appropriate. Again the-Substate Six Plan and

the Southern Strafford Report in part address the problem of "value" setting.

Both encourage preservation of wetlands while the latter encourages strict

regulations in seasonally--wet soils. S.-C.-S. di-scourages devel-6pment on highly

erodible soils on steep slopes.---The remainder-of.the-soi,ls-were evaluate&by

the staff on the basis of their ability to physically accommodate urban develop-

ment. Below the soils are listed generally according to their capability for

urban development, from least to most capable based upon the judgemental process

outlined above.

Wetland Soils

These usually formed in associ ati on wIth the marine silts and clays, the
sand and gravel deposits, till, and the more recent alluvial sediments deposited

by streams and rivers. They Include all the Poorly drained mineral and organic

soils, i.e., those.having a wa ter table at or near the ground surface for seven
or more months of the year (Kelsey, 1973-74).

Wetland toils are best left undeveloped because many occur In natural

drainage ways and are valuable when left uhtbuched. Not only do they act as

natural sponges to collect excess runoff, thus preventing floodi.nq downstream,
but they also serve as a habitat for fish and wildlife. These areas have open

space and recreational potential. Because of their ecological value wetland
soils (including tidal wetlands) have been recommended as "areas of particular

concern". See Areas of Particular Concern discussion for more details.

Highly Erodible Soils

The highly erodible soils are located in marine clay deposits, often

adjacent to the tidal rivers such as the Cocheco. Development on these soils

is generally not recommended, because of the high potential for erosion and

stream pollution. They are best left in vegetative cover. Where construction

is necessary, proper erosion and sediment controls must be used. S-ince the

erosion and sedimenta tion potential of these soils Is so great, they have been

recommended as "areas of particular concern" In the Primary Zone.

Seasonally Wet Soils

These soils formed in association with parent materials similar to those

of the wetland soils, although they are g_pneral.1 better drained. ---This group
Y - -

includes all moderately well-drained soils or those having a water table within
IP, to 2-12- feet of the ground surface during parts of the year (Kelsey, 1973-74-).

Development of seasonally wet soils should be avoided where at all possible.

Wet basements and submerged leach fields of septic tanks can be expected,.with

a distinct possibility of groundwater pollution. Only when waterpfoof municipal

sewer facilities or similar protective measures can be provided should these soils

be developed. Waste disposal-and fertilizer-application should be discouraged.

Shallow to Bedrock Soils

These soils are located on thin deposits of glacial till. Bedrock or ledge

in much of the deli neated areas is typically 30 inches or less below the ground

surface. Shallow to bedrock soils are so thin to bedrock that high density or

commercial development is usually unwise because of high costs of constructing

foundation and septic tanks or sewer lines. Any kind of development should be

of low density on large lots. However, a community may want to overcome the

bedrock limitation by constructing water and sewer facilities to serve high

density development, which would offset the cost of these services. Newmarket

is a good example of this practice.

Clays and Sands Over Clay Soils

The group consists of all well-drained clays and all well-drained sands

over clay soils. Although these soils are generally well-drained, they are

somewhat slowly permeable because of the clay layer. As a result a drainage

system around the foundation is suggested to carry off water to a settling pond

or storm sewer. This system can be quite expensive, but needed in order to

avoid any possibility of flooded basements. No an-site spptic systems should

be allowed because of the potential for groundwater pollution. Only develop-

ments that can afford to offset the above limitations should be considered here.

Deep, Well-Drained, Stony --- (with-hardpan) Soils-

These soils occur under-the same conditions as the above but typically

have a hardpan at about two feet that restricts the downward and lateral move-
ment of water (Kelsey, 1974-75).

While the deep, stony hardpan soils may be well@dratned, on-site septic

systems should not be used on small lots. The moderately slow permeability

and the possibility of a perched water table above the pan are limitations that

could lead to groundwater pollution. -Development with water and sewer is recom-

mended especially where densities are relatively high.

in Rockingham County the previous two categories are combined Into the follow-

Ing one, since there was no distinction in the soil survey between those deep

stony soils that had a hardpan and those that did not.

Deep Stony Soils

This group of soils formed in glacial till and comprise all well-drained

and small areas of poorly,drained stony soils, These soils mo@ ormay not haye

hardpan layers. These soils have the same limitations as the deep, well-drained

stony, hardpan soils of Strafford County.

Deep, Well-Drained,-.Stony (non-hardpan) Soils

The deep well-drained stony group consists of well-drained loamy soils
that are formed in deep, sandy, stony, glacial till. @V*
Although these soils are quite variable in character, most types of devel-

opment can be considered. The only limitations are stones and clay lenses that

might hinder foundation and septic tank construction and drainage.

Sandy and Gravelly Soils CENTE
This group includes--all well-drained to excessively well-drained soils
that have formed in thick sand and gravel deposits.

Sand and gravel soi.ls ha ve -the -best potential for development since they

offer few if any restrictions to construction. However, intensive development
with impervious surfaces (roads,-par-king-lots, etc.-)-can prevent recharge to the

groundwater reservoirs-Inthese-deposits- which mjay,_ beneeded for future water
supplies. In addition, if septic tanks are used, they must be carefully constructed
and regulated to prevent groundwater contamination from the effluent. High

density development must definitely be discouraged in sand and gravel areas

where municipal wells are located. The Groundwater section of the inventory

covers this more fully.

Prime Agricultural Soils

Prime agricultural soils were also designated in the inventory, although
not on the soils condition maps. Criteria used to determine these soils were

determined by the Soil Conservation Service. Because of the long-term value

of such soils these areas were recommended as Areas of Particular Concern. See

that section for a more detailed discussion of these areas. Both the Subs tate

Six Plan and the Southern Strafford Report encourage maintenance of agricultural

-17-

and prime agricultural lands as policy,

In conclusion, It must be recognized that neither soil survey is accurate

to the site specific level, particularly Rockingham County's Therefore, rigid

land use regulations should not be formulated for specific soil cate gories or

soil types. Where land use.ordinances depend on soil criteria, standards and

regulations should be flexible enough to allow intelligent planning and manage-

ment decisions. Such requirements as on-site investigations for certain types

or sizes of development is one method for encouraging good planning.

SLOPE

Consideration of slope or steepness of the land in the natural resource

inventory is important, because it plays a significant role in the capability of

any site for most land uses. For-instance., flat sites are suitable for such

uses as roads and highways, large commercial and industrial buildings, agricul-

turel and intensive recreation. As the slopes become steeper many of the uses
are not suitable. In add I ti on,_AeVel dpment.-.'and--service -C'osts':increase. -The@-.
greatest hazard from devel.opment on any but the flattest slopes is erosion. As
.the slope gradient increases-the potential for erosion and water quality deter--.

ioration is greatly enhanced. These conditions become of-critical concern

particularly in the Primary Zone where there Is potential for significant impact
on coastal waters.

Using the U.S.G.S. contour base maps four categories of slope were designated:

0-8%, 8-15%, 15-25%, and 25% and greater. Percent slope is determined by expres-

sing the vertical change as a ratio of the horizontal change. For example, a verti-

cal change of 5 feet with a horizontal change of 20 feet Is equivalent to a 25%

slope. These categories were developed by the S.C.S. and have been in use

in the northeastern region of the United States for many years. According
to Pilgrim (1976), the slope categories were based upon two major factors:
(1) the major landscape units in this region of the country correspond to

these categories and (2) the agricultural land management programs recommended

by the S.C.S. used these slope breakdowns with success. In addition, recommended
soil limitation categories (slight, moderate, severe) for excavating dwellings,
septic tanks, etc. rely heavily on these slope breakdowns (Soil Conservation

Service, 1971).

Slope limitations for most uses become severe or critical when the slope

is 15% or greater. Both S.C.S. and the Southern Strafford Report regard steep

slopes as areas of hazard and potentially sigHficant environmental impact if

developed. Numerous subdivision ordinances in the coastal zone communities

also address this problem.

Based upon the above considerations the slopes were rank ordered from

least to most capable using the-S,C.S. slope breakdowns, See Figure 5.
Some suggested land uses for each slope category: 1/,"4

0-3% Flat lands are suitable for most large buildings Industrial and

commercial. Roads, highways,and active recreation uses such as ball

fields are also suitable for these flat areas. Very flat sites may
pose such problems as (1) inadequate dratnage especially during
peak storms; and (2) inadequate gravity flow.for sanitary sewers.

3-8% These gently undulating areas are suitable for single family housing

on small and medium lots, apartment buildings, secondary roads, as

well as most of the activities above, with increasing limitations at

the upper extreme-of the category.

8-15% Development costs and the potential for runoff and erosion begin

to increase. These areas are suitable for single family hou'sing on

large lots-, townhouses, and garden apartments..

15-25% Townhouses with multi-level entrances, using the cluster technique,

can be considered in these areas. The cost of development becomes
a major factor. Run off and -erosion control-is essential. These'
slopes have been recommendedfor inclusion as Areas of.Particular

.Concern in the Primary Zone.

_19-

M A 11, 11,(' 2 0/ 2 5' 30'

b 0
45
40,

35'

GRADUAL SLOPE STEE-P- S,L PE

IJ.

25%

Figure 5. Diagram to Illustrate percent slope.
0
0/ ((@@@5450" @
0,

-20-

25% Almost all development should be preyented, DeyelQpment costs and
and
over potential environmental impact are high. Such factors as shallow depth

to bedrock, drainage.problems, runoff and erosion severely I imit con-

struction on these slopes. For these reasons such slopes-in the

Primary Zone are also recommended as Areas of Particular Concern.

GROUNDWATER

Groundwater occurs in openings or pores In the bedrock or surficial materials.

The amount of water that these materials can hold depends upon the size and

number of the openings and the particle size of the geologic material. If..a.-

geologic deposit or unit has numerous openings it is said to be porous. Per-

meability is the capacity of a given geologic unit to transmit water. In order

to have large yields of groundwater, the deposit must have high porosity and

permeability. Since sands and gravels have large particles and large pore spaces,

they are permeable enough to produce high yields of groundwater. This type of
deposit is called an aquifer (a geologic unit that yields significant amounts of
water).

The chief source of groundwater is precipitation. Of the precipitation that

falls to the earth's surface a small fraction runs directly off the su rface,

while much of it flows toward streams just below the earth's surface by means

of a process called interflow. Much of the rest returns to the atmosphere

through evaporation from surface water or transpiration from vegetation (evapo-
transpiration). In the coastal area of New Hampshir4 of the approximately
42 Inches of precipitation received annually, half or about 21 inches is

lost to evapotranspiration. The remainder infiltrates through the soil to

recharge the groundwater. The point at which the geologic unit is completely

saturated is known as the water table. See Figure 6.

The best potential aquifers in New Hampshire's coastal zone are the large

sand and gravel deposits. See Groundwater Potential Maps, Good Potential Areas.

Because of their excellent permeability,yields as high as 700 gallons per minute

_91-

PRECIPITAT 6N'v, ;'57-APO-AA ION,'

TRANSPIRATION FROM VEGETATION=

Jog!
M-1
.T r

i4p
WTI, i,@
'-REA@-
Jill) -SOILS-@@-

P jo
Jv
W
RECHARGE
�0 P, FAC-C VIAT E.R'.

B .7Z*.
WATER TABLE
-7:ZONE OF S A T LFfR'-A-T-'f'0-N'=
71- -

Figure 6i Relationship of Qroundwater to the Hydrologic Cycle.

Coe%.
, Z@__ . @14
i, R E CAF--aw@

(gpm) may be obtained (Bradley, 1964). On the Groundwater Potential Maps these
areas are either in dark blue or coded as the number I (good potential). In

some instances these deposits are too thin or too small to provide sizeable

reservoirs of water. These are Indicated by medium blue color and categorized

as moderate potential.

The outwash and shore deposits are moderatbly permeabl6 and can be expected
to yield up to 100 gpm (Bradley, 1964). This kind of yield is suitable for

residential, farm, and small industrial supplies. Where well-sorted medium or

coarse sands occur in known andient geologic valleys, the saturated thickness
may be quite deep.. According to Cotton.(1975) these aquifers could yield
over a million gallons.of water per day. Field work is necessary to make.
determinations abou't-s-Uch depo-si-t's and*is highly recommended.-

Till and marine clay have generally poor potential for anything but domes-

tic water supplies although the groundwater potential paps have distinguished

between the two. This was done to Indicate a potentially good supply of water

under the marine clays. In some instances these.clays lie above excellent sand
and gravel or outwash deposits, part1cul .arly adjacent to rivers. This situation

occurs along the Exeter River in Exeter where the town has a municipal well.

The small areas of alluvium and swamp deposits were classified as poor potential.

Of all the natural resources, groundwater Is probably the single most limit-
Ing factor to the amount and type of-development In the coastal zone of New-'

Hampshire. Right now groundwater is the principal source of water in the area.
According to Hall (1974) of the 16 million gallons per day water consumption in

the seacoast area, 10.5 mgd comes from groundwater. Present population projection

indicates that the seacoast area will run out of groundwater supplies by the

middle 1980's. This is based--on a sustained-wateryield figurf@e of 25-nf�d-, Which
both Hall (1973) and Anderson-Nichold (1969-72) calculate. It is quite clear

that the coastal area is facing a potential ctisis. In order to meet this

need, new sources of water will soon have to be developed either locally or from

-23-

outside sources. Any such water supply development should be coordinated with

growth management policies..

For these reasons,lt is essential that groundwater resources be protected

from contamination in areas that are presently being used as water supplies or

that are potential future water supplies. These areas Include many sand and

gravel deposits as well as some outwash and shore deposits. In some instances

medium density development on water and sewer is appropriate in these areas. It

is important to prevent Incompatible uses, such as oil storage facilities,

that might lead to groundwater contamination. Growth should also be controlled

to regulate the amount of Impermeable cover, such as roofs and parking lots, in
order to maintain adequate recharge of the aquifers. See Mettee (1974) for a more

detailed discussion of g-roundwater and its implications for growth in the coastal

area of New Hampshire.

For purposes of the inventory mapping,the surficial deposits were Interpre-

ted for their ability to yield water. The categories for the Groundwater

Potential Maps are: ...

Class--- Deposit

1) Good Potential Excellent sand and gravel
aquifers
2) Moderate Potential Thin or small sand and gravel
deposits
3) Poor Potential- Till, Alluvium Swamp deposits,
Marine clays*

These were distinguidhed from the other deposits of poor potential.
While they usually are of poor potential, they often overlie exten-
sive sand and gravel aquifers as noted in the discussion. It was
decided that this circumstance was worth noting.

Because of their present and potential water bearing capacity, those sand and

gravel areas in the Good class--have been recommended-as Areas of Particular

Concern. 'Jhe Southern Strafford Study recommends protection for these aquifers.

SURFACE WATER

The Surface Drainage Maps indicate the relative vulnerability of the various

_9A_

sub-basins in the primary and secondary coastal zone which are part of the Coastal

Watershed.

Each stream or basin on the surface drainage maps is assigned a stream or

basin order designation based upon the tributaries of each stream. For instance,

b headwater stream with no tributaries is classified as a first order stream

while a second order stream has at least two first order tributaries, and no

tributary larger than a first order. Similarly, a third order stream has at

least two second order tributaries, and no tributaries greater than a second

order.

This drainage basin approach has been used in the scientific community

as a means to 1dentify.and describe erosional and drainage characteristics
of the landscape (see Horton and Strahler). -It has been adopted for planning

ee
purposes in several studies using the concept of assimilative capacity,4. S'

Metcalf and Eddy, p 673, 1972 and Parker, H.W. , p.119, 1975),,to determine land

capability as explained below. (See Atlanta Regional Commission, 1972 and
Frederick, Jr., C.J...,-1.972.-)-.-Although.there are no specific regional or

local policies that address surface drainage, both the Substate Six Plan and

the Southern Strafford Study have stated policies with.regard to water resource

protection. It is the judgement of the staff that the above system has scienti-

fic, merit and is appropriately used here.

In general, surface water that originates at the headwaters of small
watersheds.are most vulnerable to impacts from development. They have less water

volume -to assimilate contaminants and dilute solids than do surface waters that have

flowed throuq@@h several stream orders before reaching thajor rivers. First order

basins are the most sensitive to disturbance, since these tend to be located

at the headwaters and have very low-flows. Any-signifi-cant changes that have
adverse impact on these streams are felt in varying degrees throughout the

drainage system. Urbanization in such areas increases surface runoff and causes

increased erosion and siltation. Since ponds and lakes are particularly vul-

nerable to the impacts of development, they are considered to be in the same

_or__

class as the headwaters or first order basins. The textured overlay on the maps

indicates a buffer zone of protection around these major water bodies. The exact

width of this buffer Is not crucial at this point, but a distance of between 100
and 300 feet is reasonable (see Strong, Keene, et. al., 1972). The recommended

regulations'Vi-1.1 treat this buffer concept more precisely.

The coastal zone has many first order basins. Because these basins have

little stream flow capacity, they have little assimilative capacity. Therefore,

the first order basins are much less desirable to develop than the second, third,

and fourth order basins.

Second order basins are less vulnerable than first order. This system

continues successfully so that the fourth order basins are the least vulnerable

or the most appropriate for development. These basins have been interpreted by

the SRRC staff from the U.S.G.S. topographic maps, 15 minute series.

WATER AND SEWER

Although these systems are man-madeF---they-were treated here because of

the Important implicat ions they-have.for-development and defining "permissible

land uses" in the coastal zone. The connotation of "suitability" is introduced

when these types of factors are considered.

The majority of the towns and cities in the coastal area have municipal

water and sewer systems. The Water and Sewer Maps indicate the extent and

coverage of each of these systems. These services generally lie within the

major population centers of these-communities such as urban areas of Dover and

Portsmouth. Th ese maps were based on information and maps provided by the

appropriate communities.

These facilities provide flexibility to gtowth patterns because they

allow developers the opportunity of overcoming some of the natural limitations

to urban growth such as high bedrock or ledge. Where it Is appropriate a.

community can develop at higher densities than with private wells and septic
systems. Clustering of development on such facilities encourages a wiser use

rie

of land and is generally more economical in the long run. However, provision
of water and sewer services does not imply that any-kind of development can go
anywhere. Critical areas such as wetlands and steep slopes should still be

avoided. For environmental and long-term economic reas ons these areas should

be protected through proper land use regulation.

It is not the purpose of this study to make specific recommendations for

future water and sewer systems. However, it is recommended that where possible

communities should cooperate in construction of such facilities. This approach
would allow greater,system flexibility and wo,uld result In lower long-term
costs to the communities involved. It is also recommended that water and sewer

planning be done on a watershed basis for ecological and economic reasons.

CLASSIFICATION

Once the various natural-factors of the-Coastal-Zone were evaluated for

their ability to support urban development, capability map classes were defined

based upon the convergence of given natural factor characteristics. For example,

since 0-8% slopes, sand and gravel soils, and fourth order drainage represent

the most propitious natural characteristics for development, they were synthe-

sized In Capability Class 1.

At the risk of making a relatively simple process become complex, it

was decided that the capability classes should identify the specific natural

characteristics that were in convergence. The alternative would have been to

aggregate more characteristics into one class, resulting in fewer capability

classes. By using the former process loss of valuable data was kept to a

minimum in going from the individual factor maps to the land use capability

map. Such a system of natural factor synthesis requires numerous capability
classes. *However-, 'it is infinitely easier for prospective users to determine,

-27-*

when necessary, specific resources from the capability map, rather than contin-

ually referring to individual natural factor maps. By definition, Capability

Class 1 in the previous example illustrates this point.

At the same time OCP requested that these numerous Individual classes be

aggregated Into four capability classes, which for the sake of simplicity will

be referred to as capability "areas" in the discussion. This procedure was

followed and the Individual map legends reflect both systems of classification.

In the aggregated system Capability Class 1 becomes Capability Area I or those

areas representing "Excellent" capabil'ity for development. The capability classes

and areas are defined at the end of this section.

More specifically, the process of mapping the various capability classes
was achieved through an ordered overlay.jg@ch_nique._ The fi-rst-.step--was to-.-ex-.-
tract from the individual factor maps those areas which by the evaluation pro-
cess were considered to present particular hazards for development (e.g., flood-

plains) or to represent areas of high social, economic, or environmental cost
(e.g., coastal wetlands) if improperly developed. These resources fall Into
what was defined as a resource protection district or the "Poor" development
capability area. This area (district) represents a grouping of resources that

leads to an initial determination of "areas of particular concern'V The

term resource protection was employed to Identify those areas whose integrity

should be protected for the good of the-whole coastal zone community. Such a

designation does not imply that these areas not be used, but only that uses

commensurate with the tolerance of the resource be allowed. Special regulations

for these areas may be needed.

Each resource has been numbered and colored where appropriate and identified

in the map legend. These resources are listed below, generally in decreasing

order of criticality or value from top to botton. See Areas of Particular

Concern discussion for an expanded discussion of these resources.

The next step was to identify the capability of the remaining areas on

-28-

the maps based on a particular combination of soil conditions, slope, and sur-

face drainage. Each of these maps was overlaid successively to determine the

various capability classes on each of the seven Land Use Capability Maps. Twelve
capability classes ranging from most c apable (#I) to least capable (#12) for

urban development have been designated. On the capability maps these have been

coded appropriately so that they are easily identifiable. To satisfy the request

of the state, these twelve classes have been divided into three groups. The

dividing points were chosen because in each instance there was a significant
enough change in one or more of the resource characteristics (categories) to

warrant a division. These groups were identified as follows: Excellent pote n-
tial for developmentj (Capability Area 1), Good potential for development,
(Capability Area 2), and Fair potential for development, (Capability Area 3).

They are defined below.

Where water and sewer are available the capability of a given area will

usually improve. While these factors were not considered in the capability

analysis per se, they will provide an essential element in determining "permissible

land uses", as discussed in a subsequent section.

This classification system leads to a definition of "permissible land uses"

for the coastal zone. Knowing the inherent cppability of the coastal.zone for

urban development, and then assessing the requirements for various land uses, the

most appropriate uses can be guided to the most capable areas. Industrial devel-
opment could be appropriately accommodated on Class 3 land (Excellent potential
for development) but not on Class 9 land (Fair potential for development).

Land Use Capability Classification

Capability Soil I/
Class Slope Condition Surface Drainage

Capability Area 1 Excellent Potential

1 0-8% 1 Fourth Order

2 0-8% 1 Second, or Third

3 0-8% 1 First; Lake Shore Buffers

Land Use Capability Classification

Capability Soil l/
Class Slope Condition- Surface Drainage

Capability Area 2 - Good Potential

4 0-8% 2 Second, Third, or Fourth

5 0-8% 2 First, or Lake Shore Buffer

Capability Area 3 - Fatr Potential

6 0-8% 3 First, or Lake Shore Buffer.

8-15% 1 Second, Third or Fourth

7 8-15% 1 First, or Lake Shore Buffer

8 0-8% 3 Second, Third, or Fourth

9 8-15% 2 Second, Third, or Fourth

10 8-1-5%-- -2 Pirst-, -or --- Lake Shore Buffer

8-15% 3 Second, Third, or Fourth

11 8-15% 3 First, or Lake Shore Buffer

12 15-25% 1, 2,*or'3' Any drainage

Capability Area 4 7 Poor Potential (Resource Protection)

1. Floodplains and/or Wetlands 3/
Highly Er@o_dible Soils

2. Floodplains and prime agricultural land 3/

3. Floodplains

4. Wetlands in Valuable Forest Areas 4/

5. Wetlands

6. Highly Erodible Soils on Steep Slopes 5/

7. Highly Erodible Soils

8. Steep Slopes in Valuable Forest Areas

9. Slopes over 25% �/

10. Ice-Contact Deposits in Valuable Forest Areas

11. Ice-Contact Depostts

12. Prime Agricultural Soils
Natural Areas 7/
Higher Hills 5/

)j Soil Conditions Groups

1. Sand and Gravelly Soils
Deep, Well-Drained Stony (non hardpan) Soils

2. Deep, Well-Drained Stony Hardpan Soils
Clays and Sands over Clayey Soils

3. Seasonally Wet Soils
Shallow to Bedrock Soils

2/ S.C.S. 100-year floodplain boundaries and 10 foot boundary for all tidal
waters based on Hall (1975), Hayden (1975), and Corps of Engineers (unknown).

S.C.S. Rockingham and Strafford Soil Survey

4/ Brunz and Lane (1969), "A Timber Inventory of the Seacoast Region".
y UiS.G.-S....-@[email protected]'es
Bradley (1964), GeoloqX and Groundwater Res'ourc6s'of'-Southeastern
N-ew Hampshire, Cotton (1974), personal communication
7j Natural Areas Inventory, Society for the Protection of New Hampshire
Forests

-31- .

REFERENCES

Anderson-Nichols & Co., Inc. 1969 - 1972. Public Water Supply Study. 4
Volumes, prepared for the State of New Hampshire, Department of Resources
and Economic Development, Concord, New Hampshire.

Atkins, J. Thomas, et. al.,. 1972. Huntington: An Environmental Planninq
Program. Unpublished Master s thesis, Department of Landscape Archttecture
and-Te--gional Planning, University of Pennsylvania, Philadelphia, Pennsylvania.

Atlanta Regional Commission. 1972. Chattahoochee Corridor Study, A.R.C.,
Atlanta, Georgia.

Bradley, Edward. 1964. Geology and Groundwater Resources of Southeastern New
Hampshire. Geological Survey Wateri Supply Paper 1695, prepared opera-
tion with the New Hampshire Water Resources Board, U.S. Government Printing
Office, Washingt on, D.C.

Brunz, Paul E. and William.Lane.'-"..1969.. "A Timber Inventory of the Seacoast
Region." Regional Plannin5: -New Hampshire Ma-ine, Part I. University
of New Hampshire, Durham, New Hampshire and Department of Resources and
Economic Development, Concord, New Hampshire.

Clark, John. 1974. Coastal Ecosystems: Ecological Cohsiderations'for Manage-
ment of the Coastal Zone. The Conservation Foundation, Washington, D.C.

Cotton, John. 1973. Geologist, Water Resources Division, U.S. Geol6gical
Survey, Concord, New Hampshire, personal communication.
Frederick, Jr., C.J. and Luty, J.J. 1972. Problem'Rec62nitioh'Study, Central
New Hampshire Planning Reg on. The Regional Field Service, Harvard Gr-a-d-uate
ol of Design, Department of -Landscape Architecture, Cambridge, Massa-
chusttts.

Hall, Francis. 1974a. Professor of Hydrology, Institute of Natural and
Environmental Resources, University of New Hampshire, Durham, New Hamp-
shire, personal communications.

1974b. "Water Requirements and Possible Sources of Supply." Chapter VI,
The Imeacts of an Oil Refinery Located in Southeastern New'Hampthire: A ' .
Preliminary SLLdX. The Un1vers1ty of New Hampshire, Durham, New Hampshire.-

Horton, R.E. "Erosional Development of Streams and Their Drainage Basins:
Hydrophysical Appraoch to Quantitative Morphology", Geographical Society
6f America Bulletin, Vol. 56, 275-370.

Institute for Environmental Studies, Regional Science Research Institute,
and United States Geological Survey. 1968. 'The'Plan and Program for the
Brand.Vine. Institute for Environmental Stud4es,.University of Pennsylvania,
M ladel;phla, Pennsylvania.

Kelsey, Theodore. 1973 - 1974. Resource Planning Specialist. Soil Conservation
Service, Durham, New Hamp shire, personal communication.

Klingbiel, A.A. and Montgomery, P.H. 1961. 'Land Capability'Classification.
Agriculture Handbook No. 210, Soil Conse-rWaTlon Service, U.5. Department
of Agriculture, U.S. Government Printing Office, Washington, D.C.

Metcalf & Eddy. 1972. Wastewater Engineeria. McGraw-Hill, New York, New
York (673).

Mettee, Jack. 1975. Southern Strafford Region: An Envirohrh6htal*Planninq
Study Strafford-Re-gTo-nal Planning Commission, Dover, New Hampshire.

Montgomery County Planning Commission. 1971. Natur6l'Ehvironment. Court
House, Norristown, Pennsylvania.

Parker, H.W. 1975. Wastewater Engineering Prentice Hall, Englewood Cliffs,
New Jersey (119).

Photographic Interpretation Corporation. 1975. New Hampshire Data Base Pilot
Study. Prepared for the Office of Comprehensive Planning, State of New
Ra-m-p-s-hire, Concord, New Hampshire.
Soil Conservation Service. 1971. Guide for Interpreting Engineering'Uses
of Soils. S.C.S., U.S. Department of Agriculture, U.S. Government Print-
ing Offi e, Washington, D.C.

Strahler, A.N. "Hypsometric (Area-Altitude) Analysis of Erosional Topography."
Geological Society of America Bulletin, Vol. 63, 1117 - 1142. This
reference has been added to ackn_o_wT_ecTg_e Strahler's further contribution
to.the formulation of this method6logy.

Substate District # 6. 1973. Preliminary Comprehensive-Land Use Plan.. Sub-
state District # 6, Exeter-, -New Hampshire.

Tourbier, Joachim. 1973. Water Resources as a Basis*for"Comprehensive Planqjnk
and Development in the CVristIna River'Basin. University of Delaware
r Resources Center, Newark, Delaware.

Van der Voet, Dirk, et. al. 1959. Soil Survey of'Rodkihqharh County, New
Hampshire. United States Department of Agriculture, Soil Conservation
Service In cooperation with New Hampthire.
Vieira, Frank J. and Bond, Richard W. 1973. Soil Survey of IStrafford Coun@yl
New Hampshire, United States Department gritulture, Soil Conservation
Service in cooperation with New Hampshire Agricultural Experiment Station,
U.S. Government Printing Office, Washington, D.C.

444

ge@

DAT-E,OUE

GAYLORD No. 2333 PRINTED IN U.S.A.

668 14108 1663