HomeMy WebLinkAbout017 - Appendix O - Stormwater Design ReportUnited States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
Gallatin County
Area, Montana
NSRX
Natural
Resources
Conservation
Service
December 11, 2023
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/
portal/nrcs/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil
Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
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alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
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Contents
Preface....................................................................................................................2
How Soil Surveys Are Made..................................................................................5
Soil Map..................................................................................................................8
Soil Map................................................................................................................9
Legend................................................................................................................10
Map Unit Legend................................................................................................11
Map Unit Descriptions.........................................................................................11
Gallatin County Area, Montana.......................................................................13
350B—Blackmore silt loam, 0 to 4 percent slopes......................................13
457A—Turner loam, moderately wet, 0 to 2 percent slopes.......................14
510B—Meadowcreek loam, 0 to 4 percent slopes......................................15
512B—Enbar-Nythar loams, 0 to 4 percent slopes.....................................17
References............................................................................................................19
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How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous
areas in a specific area. They include a description of the soils and miscellaneous
areas and their location on the landscape and tables that show soil properties and
limitations affecting various uses. Soil scientists observed the steepness, length,
and shape of the slopes; the general pattern of drainage; the kinds of crops and
native plants; and the kinds of bedrock. They observed and described many soil
profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The
profile extends from the surface down into the unconsolidated material in which the
soil formed or from the surface down to bedrock. The unconsolidated material is
devoid of roots and other living organisms and has not been changed by other
biological activity.
Currently, soils are mapped according to the boundaries of major land resource
areas (MLRAs). MLRAs are geographically associated land resource units that
share common characteristics related to physiography, geology, climate, water
resources, soils, biological resources, and land uses (USDA, 2006). Soil survey
areas typically consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that
is related to the geology, landforms, relief, climate, and natural vegetation of the
area. Each kind of soil and miscellaneous area is associated with a particular kind
of landform or with a segment of the landform. By observing the soils and
miscellaneous areas in the survey area and relating their position to specific
segments of the landform, a soil scientist develops a concept, or model, of how they
were formed. Thus, during mapping, this model enables the soil scientist to predict
with a considerable degree of accuracy the kind of soil or miscellaneous area at a
specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented
by an understanding of the soil-vegetation-landscape relationship, are sufficient to
verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them
to identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character
of soil properties and the arrangement of horizons within the profile. After the soil
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scientists classified and named the soils in the survey area, they compared the
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that
have similar use and management requirements. Each map unit is defined by a
unique combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components
of the map unit. The presence of minor components in a map unit in no way
diminishes the usefulness or accuracy of the data. The delineation of such
landforms and landform segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, onsite
investigation is needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape,
and experience of the soil scientist. Observations are made to test and refine the
soil-landscape model and predictions and to verify the classification of the soils at
specific locations. Once the soil-landscape model is refined, a significantly smaller
number of measurements of individual soil properties are made and recorded.
These measurements may include field measurements, such as those for color,
depth to bedrock, and texture, and laboratory measurements, such as those for
content of sand, silt, clay, salt, and other components. Properties of each soil
typically vary from one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists
interpret the data from these analyses and tests as well as the field-observed
characteristics and the soil properties to determine the expected behavior of the
soils under different uses. Interpretations for all of the soils are field tested through
observation of the soils in different uses and under different levels of management.
Some interpretations are modified to fit local conditions, and some new
interpretations are developed to meet local needs. Data are assembled from other
sources, such as research information, production records, and field experience of
specialists. For example, data on crop yields under defined levels of management
are assembled from farm records and from field or plot experiments on the same
kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on
such variables as climate and biological activity. Soil conditions are predictable over
long periods of time, but they are not predictable from year to year. For example,
soil scientists can predict with a fairly high degree of accuracy that a given soil will
have a high water table within certain depths in most years, but they cannot predict
that a high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
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identified each as a specific map unit. Aerial photographs show trees, buildings,
fields, roads, and rivers, all of which help in locating boundaries accurately.
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Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
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Custom Soil Resource Report
Soil Map
50550805055150505522050552905055360505543050555005055080505515050552205055290505536050554305055500494980 495050 495120 495190 495260 495330 495400 495470 495540 495610 495680
494980 495050 495120 495190 495260 495330 495400 495470 495540 495610 495680
45° 39' 11'' N 111° 3' 52'' W45° 39' 11'' N111° 3' 19'' W45° 38' 56'' N
111° 3' 52'' W45° 38' 56'' N
111° 3' 19'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 12N WGS84
0 150 300 600 900
Feet
0 45 90 180 270
Meters
Map Scale: 1:3,260 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Gallatin County Area, Montana
Survey Area Data: Version 27, Aug 25, 2023
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Aug 18, 2022—Aug
29, 2022
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
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Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
350B Blackmore silt loam, 0 to 4
percent slopes
0.7 1.9%
457A Turner loam, moderately wet, 0
to 2 percent slopes
3.2 8.4%
510B Meadowcreek loam, 0 to 4
percent slopes
31.7 83.9%
512B Enbar-Nythar loams, 0 to 4
percent slopes
2.2 5.8%
Totals for Area of Interest 37.8 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
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The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, however,
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
An identifying symbol precedes the map unit name in the map unit descriptions.
Each description includes general facts about the unit and gives important soil
properties and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major
horizons that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness,
salinity, degree of erosion, and other characteristics that affect their use. On the
basis of such differences, a soil series is divided into soil phases. Most of the areas
shown on the detailed soil maps are phases of soil series. The name of a soil phase
commonly indicates a feature that affects use or management. For example, Alpha
silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps.
The pattern and proportion of the soils or miscellaneous areas are somewhat similar
in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present
or anticipated uses of the map units in the survey area, it was not considered
practical or necessary to map the soils or miscellaneous areas separately. The
pattern and relative proportion of the soils or miscellaneous areas are somewhat
similar. Alpha-Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas
that could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion
of the soils or miscellaneous areas in a mapped area are not uniform. An area can
be made up of only one of the major soils or miscellaneous areas, or it can be made
up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil
material and support little or no vegetation. Rock outcrop is an example.
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Gallatin County Area, Montana
350B—Blackmore silt loam, 0 to 4 percent slopes
Map Unit Setting
National map unit symbol: 56q7
Elevation: 4,850 to 5,550 feet
Mean annual precipitation: 18 to 22 inches
Mean annual air temperature: 37 to 43 degrees F
Frost-free period: 80 to 95 days
Farmland classification: All areas are prime farmland
Map Unit Composition
Blackmore and similar soils:90 percent
Minor components:10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Blackmore
Setting
Landform:Stream terraces
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Calcareous loess
Typical profile
A - 0 to 10 inches: silt loam
Bt - 10 to 27 inches: silty clay loam
Bk1 - 27 to 42 inches: silt loam
Bk2 - 42 to 60 inches: silt loam
Properties and qualities
Slope:0 to 4 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20
to 0.57 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:30 percent
Available water supply, 0 to 60 inches: High (about 11.4 inches)
Interpretive groups
Land capability classification (irrigated): 4e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: C
Ecological site: R043BP818MT - Upland Grassland Group
Hydric soil rating: No
Minor Components
Bowery
Percent of map unit:5 percent
Landform:Alluvial fans, stream terraces
Down-slope shape:Linear
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Across-slope shape:Linear
Ecological site:R044BB032MT - Loamy (Lo) LRU 01 Subset B
Hydric soil rating: No
Blackmore
Percent of map unit:3 percent
Landform:Stream terraces
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R043BP820MT - Upland Shrubland Group
Hydric soil rating: No
Brodyk
Percent of map unit:2 percent
Landform:Stream terraces
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R044BB030MT - Limy (Ly) LRU 01 Subset B
Hydric soil rating: No
457A—Turner loam, moderately wet, 0 to 2 percent slopes
Map Unit Setting
National map unit symbol: 56tb
Elevation: 4,300 to 5,200 feet
Mean annual precipitation: 15 to 19 inches
Mean annual air temperature: 39 to 45 degrees F
Frost-free period: 90 to 110 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Turner and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Turner
Setting
Landform:Stream terraces
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Alluvium
Typical profile
A - 0 to 6 inches: loam
Bt - 6 to 12 inches: clay loam
Bk - 12 to 26 inches: clay loam
2C - 26 to 60 inches: very gravelly loamy sand
Properties and qualities
Slope:0 to 2 percent
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Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.57 to 1.98 in/hr)
Depth to water table:About 48 to 96 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:15 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water supply, 0 to 60 inches: Low (about 5.4 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: B
Ecological site: R044BB032MT - Loamy (Lo) LRU 01 Subset B
Hydric soil rating: No
Minor Components
Beaverton
Percent of map unit:5 percent
Landform:Alluvial fans, stream terraces
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R044BP818MT - Upland Grassland
Hydric soil rating: No
Meadowcreek
Percent of map unit:5 percent
Landform:Stream terraces
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R044BP815MT - Subirrigated Grassland
Hydric soil rating: No
Turner
Percent of map unit:5 percent
Landform:Stream terraces
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R044BB032MT - Loamy (Lo) LRU 01 Subset B
Hydric soil rating: No
510B—Meadowcreek loam, 0 to 4 percent slopes
Map Unit Setting
National map unit symbol: 56vt
Elevation: 4,200 to 5,950 feet
Mean annual precipitation: 12 to 18 inches
Mean annual air temperature: 39 to 45 degrees F
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Frost-free period: 90 to 110 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Meadowcreek and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Meadowcreek
Setting
Landform:Stream terraces
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Alluvium
Typical profile
A - 0 to 11 inches: loam
Bg - 11 to 25 inches: silt loam
2C - 25 to 60 inches: very gravelly sand
Properties and qualities
Slope:0 to 4 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Somewhat poorly drained
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.57 to 1.98 in/hr)
Depth to water table:About 24 to 42 inches
Frequency of flooding:None
Frequency of ponding:None
Maximum salinity:Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm)
Available water supply, 0 to 60 inches: Low (about 5.1 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: C
Ecological site: R044BP815MT - Subirrigated Grassland
Hydric soil rating: No
Minor Components
Blossberg
Percent of map unit:10 percent
Landform:Terraces
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R044BP815MT - Subirrigated Grassland
Hydric soil rating: Yes
Beaverton
Percent of map unit:5 percent
Landform:Alluvial fans, stream terraces
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R044BP818MT - Upland Grassland
Hydric soil rating: No
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512B—Enbar-Nythar loams, 0 to 4 percent slopes
Map Unit Setting
National map unit symbol: 56vw
Elevation: 4,300 to 6,100 feet
Mean annual precipitation: 15 to 19 inches
Mean annual air temperature: 37 to 45 degrees F
Frost-free period: 90 to 110 days
Farmland classification: Farmland of local importance
Map Unit Composition
Enbar and similar soils:60 percent
Nythar and similar soils:30 percent
Minor components:10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Enbar
Setting
Landform:Flood plains
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Loamy alluvium
Typical profile
A - 0 to 22 inches: loam
Cg - 22 to 49 inches: sandy loam
2C - 49 to 60 inches: very gravelly loamy sand
Properties and qualities
Slope:0 to 4 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Somewhat poorly drained
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.57 to 1.98 in/hr)
Depth to water table:About 24 to 42 inches
Frequency of flooding:Rare
Frequency of ponding:None
Calcium carbonate, maximum content:10 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water supply, 0 to 60 inches: Moderate (about 8.8 inches)
Interpretive groups
Land capability classification (irrigated): 3w
Land capability classification (nonirrigated): 3w
Hydrologic Soil Group: C
Ecological site: R044BP815MT - Subirrigated Grassland
Hydric soil rating: No
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Description of Nythar
Setting
Landform:Flood plains
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Loamy alluvium
Typical profile
A - 0 to 8 inches: loam
Bg - 8 to 33 inches: silt loam
Cg - 33 to 60 inches: sandy loam
Properties and qualities
Slope:0 to 4 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Very poorly drained
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.57 to 1.98 in/hr)
Depth to water table:About 0 to 12 inches
Frequency of flooding:Rare
Frequency of ponding:None
Available water supply, 0 to 60 inches: High (about 9.7 inches)
Interpretive groups
Land capability classification (irrigated): 5w
Land capability classification (nonirrigated): 5w
Hydrologic Soil Group: B/D
Ecological site: R043BP801MT - Bottomland Group
Hydric soil rating: Yes
Minor Components
Straw
Percent of map unit:5 percent
Landform:Stream terraces
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R044BB032MT - Loamy (Lo) LRU 01 Subset B
Hydric soil rating: No
Blossberg
Percent of map unit:5 percent
Landform:Flood plains
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R044BP815MT - Subirrigated Grassland
Hydric soil rating: Yes
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References
American Association of State Highway and Transportation Officials (AASHTO).
2004. Standard specifications for transportation materials and methods of sampling
and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of
wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife
Service FWS/OBS-79/31.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. Hydric soils of the United States.
Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric
soils in the United States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service.
U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/national/soils/?cid=nrcs142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for
making and interpreting soil surveys. 2nd edition. Natural Resources Conservation
Service, U.S. Department of Agriculture Handbook 436. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577
Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580
Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and
Delaware Department of Natural Resources and Environmental Control, Wetlands
Section.
United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of
Engineers wetlands delineation manual. Waterways Experiment Station Technical
Report Y-87-1.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/
home/?cid=nrcs142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/
detail/national/landuse/rangepasture/?cid=stelprdb1043084
19
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/soils/scientists/?cid=nrcs142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States,
the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook
296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?
cid=nrcs142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf
Custom Soil Resource Report
20
South Range Crossing
Dipra Consequence Score Sheet
(in)(points)Classification (points)(ft)(points)(yes/no)(points)
Onsite <24 0 Routine 0 <10 0 Yes 0 0
Total
PointsLocation
Pipe Diameter Location Depth of Cover Alternate Water Supply
N:\5659\011 -YTI Development\04 Design\Calcs\Corrosivity\5659.011_South Range_CorrosivityScoreSheets.xlsx 1 of 2
South Range Crossing
Dipra Corrosivity Likelihood Score Sheet
(ohm-cm)(points)(ppm)(points)(%)(points)(yes/no)(points)(s.u.)(points)(ppm)(points)(mv)(points)Yes/No (points)
TP-1 979 25 124 8 >15 5 yes 5 7.7 0 48 4 292 0 Yes 2 49
TP-2 1600 19 48 0 >15 5 yes 5 7.6 0 56 4 287 0 Yes 2 35
TP-5 1410 22 20 0 >15 5 yes 5 7.5 0 29 4 288 0 Yes 2 38
TP-6 1620 19 27 0 >15 5 yes 5 7.8 0 28 4 284 0 Yes 2 35
Total
PointsSample
Bi-Metallic ConsiderationsRedox PotentialSulfide IonsPHGround Water InfluenceMoisture ContentChloridesResistivity
N:\5659\011 -YTI Development\04 Design\Calcs\Corrosivity\5659.011_South Range_CorrosivityScoreSheets.xlsx 2 of 2
TP-1
TP-2, and TP-6
TP-5
5
< 500 ohm-cm 30
500 - 1000 ohm-cm 25
> 1000 - 1500 ohm-cm 22
> 1500 - 2000 ohm-cm 19
> 2000 - 3000 ohm-cm 10
> 3000 - 5000 ohm-cm 5
> 5000 ohm-cm 0
> 100 ppm = positive 8
50 - 100 ppm = trace 3
< 50 ppm = negative 0
> 15% = Wet 5
5 - 15% = Moist 2.5
< 5% = Dry 0
Pipe below the water 5
table at any time
pH 0 - 4 4
pH > 4 - 6 1
pH 6 - 8, with sulfides
and low or negative redox 4
pH > 6 0
positive ( 1 ppm)4
trace ( > 0 and < 1 ppm) 1.5
negative ( 0 ppm) 0
= negative 2
= positive 0 - 100 mv 1
= positive > 100 mv 0
Connected to noble metals 2
(e.g. copper) - yes
Connected to noble metals 0
(e.g. copper) - no
TOTAL POSSIBLE POINTS
Cinders, Mine Waste, Peat Bog,
Landfill, Fly Ash, Coal
RESISTIVITY
CHLORIDES
MOISTURE
CONTENT
GROUND WATER
INFLUENCE
pH
SULFIDE
IONS
REDOX
POTENTIAL
BI-METALLIC
CONSIDERATIONS
Known Corrosive
Environments
POINTS
30
8
5
5
4
4
2
2
60
21
* Soils with Known Corrosive Environments shall be assigned 21 points
or the total of points for Likelihood Factors, whichever is greater.
Likelihood Score Sheet
TABLE 2
– >
– >
MAXIMUM
POSSIBLE
POINTS
LIKELIHOOD FACTOR
6
DIPRA and Corrpro again listened to the needs of utility
operators and recognized the differences between long,
large diameter, straight-run transmission mains and the
more complicated networks of distribution pipelines that
bring water to our neighborhoods and businesses. The result
provides a more practical solution for pipeline networks that
comprise the distribution systems within a utility’s service
area. The use of V-Bio® enhanced polyethylene encasement
in conjunction with metallized zinc provides water operators
with an effective alternative to controlling corrosion in
distribution systems.
3” to 24” 0
30” to 36” 8
42” to 48” 12
54” to 64” 22
Routine (Fair to good access,
minimal traffic/other utility 0
consideration, etc.)
Moderate (Typical business/
residential areas, some right 8
of way limitations, etc.)
Difficult (Subaqueous
crossings, downtown
metropolitan business areas, 20 multiple utilities congestion,
swamps, etc.)
0 to 10 feet depth 0
> 10 to 20 feet depth 3
> 20 feet depth 5
Alternate supply available - no 3
Alternate supply available - yes 0
TOTAL POSSIBLE POINTS
PIPE SERVICE
LOCATION:
Construction-Repair
Considerations
DEPTH OF COVER
CONSIDERATIONS
ALTERNATE WATER SUPPLY
POINTS
22
20
5
3
50
Consequence Score Sheet
TABLE 3
The revised
DDM® recognizes
the practical
differences in
corrosion control
needs between
transmission mains
and distribution
systems.
MAXIMUM
POSSIBLE
POINTS
CONSEQUENCE FACTOR
= Data Input Cell
Measuring Depth GW Depth Measuring Depth GW Depth Measuring Depth GW Depth Measuring Depth GW Depth Measuring Depth GW Depth Measuring Depth GW Depth Measuring Depth GW Depth Measuring Depth GW Depth Measuring Depth GW DepthMeasuring DepthGW Depth
5 4981.350 4983.720 4.97 -2.60 5.03 -2.66 5.01 -2.64 5.59 -3.22 6.60 -4.23 6.65 -4.28 6.72 -4.35 7.32 -4.95 7.27 -4.9 6.84 -4.47
6 4988.690 4991.390 5.71 -3.01 5.84 -3.14 5.82 -3.12 5.40 -2.7 5.02 -2.32 5.70 -3 6.03 -3.33 6.89 -4.19 6.91 -4.21 6.32 -3.62
7 4987.860 4989.980 5.07 -2.95 5.21 -3.09 4.82 -2.7 4.90 -2.78 4.20 -2.08 5.00 -2.88 5.60 -3.48 6.12 -4 6.34 -4.22 5.45 -3.33
8 4980.500 4982.060 4.21 -2.65 4.31 -2.75 4.26 -2.7 4.57 -3.01 4.78 -3.22 5.40 -3.84 5.87 -4.31 6.30 -4.74 6.54 -4.98 5.78 -4.22
New 9 4974.717 4979.013 6.84 -2.54 6.90 -2.60 6.45 -2.154 5.95 -1.654 6.10 -1.804 6.80 -2.504 6.69 -2.394 7.52 -3.224 7.37 -3.074 6.78 -2.484
10 4969.270 4972.179 4.85 -1.94 4.87 -1.96 4.87 -1.961 4.60 -1.691 4.73 -1.821 4.45 -1.541 5.20 -2.291 5.79 -2.881 5.51 -2.601 5.28 -2.371
11 4969.810 4971.928 Empty #N/A empty #N/A Empty #N/A Empty #N/A Empty #N/A Empty #N/A Empty #N/A Empty #N/A Empty #N/A Empty #N/A
12 4962.290 4965.623 4.42 -1.09 4.39 -1.06 4.40 -1.067 4.42 -1.087 4.45 -1.117 4.60 -1.267 4.57 -1.237 4.78 -1.447 4.49 -1.157 4.44 -1.107
13 4961.347 4963.156 3.92 -2.11 4.28 -2.47 3.92 -2.111 3.50 -1.691 3.52 -1.711 4.20 -2.391 6.09 -4.281 6.32 -4.511 6.45 -4.641 6.41 -4.601
14 4969.707 4972.136 4.10 -1.67 4.10 -1.67 4.09 -1.661 4.59 -2.161 5.66 -3.231 4.75 -2.321 6.00 -3.571 6.12 -3.691 6.20 -3.771 4.70 -2.271
15 4971.074 4974.457 5.51 -2.13 5.78 -2.40 5.74 -2.357 5.41 -2.027 5.45 -2.067 5.75 -2.367 6.40 -3.017 6.64 -3.257 6.63 -3.247 6.28 -2.897
16 4976.443 4978.868 4.97 -2.55 5.32 -2.89 4.97 -2.545 4.82 -2.395 4.11 -1.685 4.90 -2.475 5.30 -2.875 5.71 -3.285 5.77 -3.345 5.06 -2.635
New 17 4971.993 4976.132 5.88 -1.74 5.07 -0.93 4.90 -0.761 4.78 -0.641 4.50 -0.361 6.20 -2.061 6.65 -2.511 6.82 -2.681 6.72 -2.581 6.28 -2.141
Date Well #5 Well #6 Well #7 Well #8 Well #9 Well #10 Well #11 Well #12 Well #13 Well #14 Well #15 Well #16 Well #17
5/26/2023 -2.60 -3.01 -2.95 -2.65 -2.54 -1.94 #N/A -1.09 -2.11 -1.67 -2.13 -2.55 -1.74
6/2/2023 -2.66 -3.14 -3.09 -2.75 -2.60 -1.96 #N/A -1.06 -2.47 -1.67 -2.40 -2.89 -0.93
6/9/2023 -2.64 -3.12 -2.70 -2.70 -2.15 -1.96 #N/A -1.07 -2.11 -1.66 -2.36 -2.55 -0.76
6/16/2023 -3.22 -2.70 -2.78 -3.01 -1.65 -1.69 #N/A -1.09 -1.69 -2.16 -2.03 -2.39 -0.64
6/23/2023 -4.23 -2.32 -2.08 -3.22 -1.80 -1.82 #N/A -1.12 -1.71 -3.23 -2.07 -1.68 -0.36
7/7/2023 -4.28 -3.00 -2.88 -3.84 -2.50 -1.54 #N/A -1.27 -2.39 -2.32 -2.37 -2.47 -2.06
7/19/2023 -4.35 -3.33 -3.48 -4.31 -2.39 -2.29 #N/A -1.24 -4.28 -3.57 -3.02 -2.88 -2.51
7/28/2023 -4.95 -4.19 -4.00 -4.74 -3.22 -2.88 #N/A -1.45 -4.51 -3.69 -3.26 -3.28 -2.68
8/11/2023 -4.90 -4.21 -4.22 -4.98 -3.07 -2.60 #N/A -1.16 -4.64 -3.77 -3.25 -3.35 -2.58
9/27/2023 -4.47 -3.62 -3.33 -4.22 -2.48 -2.37 #N/A -1.11 -4.60 -2.27 -2.90 -2.64 -2.14
9/27/20237/28/2023 8/11/2023Well / Date Ground Elevation Measuring Point Elevation 6/9/2023 6/16/2023 7/19/20236/23/2023 7/7/20235/26/2024 6/2/2023
-6.00
-5.00
-4.00
-3.00
-2.00
-1.00
0.00
5/14/2023 6/3/2023 6/23/2023 7/13/2023 8/2/2023 8/22/2023 9/11/2023 10/1/2023 10/21/2023
DEPTH TO GROUNDWATERMONITORING DATE
2023 Groundwater Monitoring
Well #5 Well #6 Well #7 Well #8 Well #9 Well #10 Well #11 Well #12 Well #13 Well #14 Well #15 Well #16 Well #17
___________________________________________________________________________________
SOUTH RANGE CROSSING NORTH SUBDIVISION – STORM WATER DESIGN REPORT
Appendix H
Storm Water Design Report for the Blackwood
Groves Subdivision
January 2022
DRAINAGE AREA # 8A
1. Calculate Area and Weighted C Factor
Contributing Area C Area (ft 2 )C * Area
ROW - Local 0.76 36398 27663
ROW - Angled 0.93 20802 19346
Commercial 0.95 43975 41776
Park 0.20 12172 2434
OS 0.20 13111 2622
Residential - Dense 0.40 99407 39763
Total 225866 133604
A = Area (acres)5.19
C = Weighted C Factor 0.59
2. Calculate Tc (Time to Concentration)
Tc Overland Flow
Tc = 1.87 (1.1-CCf)D1/2/S1/3
Storm
S = Slope of Basin (%)1.00 Return (yrs)Cf
C = Rational Method Runoff Coefficient 0.40 2 to 10 1
Cf = Frequency Adjustment Factor 1.1 11 to 25 1.1
D = Length of Basin (ft)360 26 to 50 1.2
51 to 100 1.25
Tc Overland Flow (minutes)23.42
Tc Gutter Flow
Tc = L/V/60
V = (1.486/n)R2/3 S1/2
n = Mannings Coefficient 0.013
R = Hydraulic Radius A/P (ft)0.13 (0.15' below top of curb)
S = slope (ft/ft)0.0160
L = length of gutter (ft)535
V = mean velocity (ft/s)3.79
Tc Gutter Flow (minutes) =2.35
Tc Total =25.77
3. Calculate Flow (Rational Formula)
Q = CIA
C = Weighted C Factor 0.59 (calculated above)
I = 0.78 Tc-0.64 (in/hr)1.34 (25-yr storm)
A = area (acres)5.19 (calculated above)
Q = REQUIRED GUTTER CAPACITY (cfs)4.11 (assuming no carry flow)
OUTLET STRUCTURE SLOT
Q=CLH3/2
Q = Discharge (cfs)1.88
C = Weir Coefficient 3.33 (per COB Design Standards)
H = Head (ft)1.5
L = Horizontal Length (ft)0.31
L = Slot Width (inches)3.7
Check the half inch requirement (per DSSP II.A.4)
1. Determine Area of Hardscape within Drainage Basin
Contributing Area Area (ft 2 )
Hardscape 156,304
2. Calculate 1/2" runoff volume over hardscape
(aka Runoff Reduction Volume [RRV] as calculated in Montana Post-
Construction Storwater BMP Manual - Equation 3-1)
RRV = [P*Rv*A]/12
P = Water quality rainfall depth 0.50 inches
Rv = Dimensionless runoff coefficient 0.475 0.05 + 0.9*I
I = Percent impervious cover (decimal)0.472 decimal
A = Entire drainage area 7.60 acres
RRV = Runoff Reduction Volume 0.150 acre-ft
RRV = Runoff Reduction Volume 4586 cubic feet