HomeMy WebLinkAboutCHRISTIAN BROTHERS AUTOMOTIVE - FDP - FDP170034 - SUBMITTAL DOCUMENTS - ROUND 1 - EROSION CONTROL LETTER/REPORTPrepared For:
CHRISTIAN BROTHERS AUTOMOTIVE CENTER
17725 KATY FREEWAY, SUITE 200
HOUSTON, TX 77094
BLOCK 1– UPLANDS PROSPECT BUSINESS PARK P.U.D.
FORT COLLINS, CO
FINAL EROSION CONTROL REPORT
October 25, 2017
Job #co 15298
PROJECT
SITE
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I. GENERAL LOCATION AND DESCRIPTION
A. Erosion Analysis
The site is currently an undeveloped platted lot of 1.147 acres. The site slopes away
from Prospect Road and Academy Court, towards the east and northeast. The majority
of the site has a slight 1 to 3 percent slope to the northeast; the eastern edge has a
slope of 3 to 5 percent slope to the east. The site is approximately 50% vegetated with
native grasses and weeds. The site appears to be mowed at least annually and non-
irrigated. The eastern 40.5-feet of the lot is covered by a utility easement containing City
of Fort Collins sanitary and storm sewer mains, the eastern portion of the easement
contains a PRPA transmission line. The Colorado and Southern Railroad lies further east
in the easement, Prospect Road to the south, and Academy Court to the west.
A light automotive service and repair facility is proposed for the site. Construction of the
project is expected to disturb approximately 0.79 acres. Construction will consist of
stripping and stocking topsoil, site grading, utility service extensions, hardscape, paving,
building construction and landscaping. Site drainage is conveyed to Spring Creek in an
existing City of Fort Collins storm sewer, installed in the eastern portion of the lot.
Currently, site drainage is conveyed to existing inlets on-site in the storm system, and
then is piped to Spring Creek. Spring Creek then, conveys the flows to the Cache La
Poudre River approximately three-quarter miles to the east of the site. The Cache La
Poudre River then flows into the South Platte River approximately 5 miles east of the
City of Greeley, CO.
An NRCS Soil Resource Report classifies the soil in the disturbed area as Kim loam, 1 to 3
percent slopes and 3 to 5 percent slopes. The report addresses the following Soil Erosion
Factors:
K Factor, Rock Free. Erosion factor K indicates the susceptibility of a soil to sheet
and rill erosion by water. Values of K range from 0.02 to 0.69. Other factors
being equal, the higher the value, the more susceptible the soil is to sheet and
rill erosion by water. The Table-K Factor, Rock Free rates the site 0.32, page 9 of
the report states this as a Null or Not Rated, water erosion potential.
T Factor. Erosion factor T is an estimate of the maximum average annual rate of
soil erosion by wind and/or water that can occur without affecting crop
productivity over a sustained period. The rate is in tons per acre per year. The
Table-T Factor rates the site 5.
Wind Erodibility Index. The wind erodibility index is a numerical value indicating
the susceptibility of soil to wind erosion, or the tons per acre per year that can
be expected to be lost to wind erosion. The Table-Wind Erodibility Index, gives
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the site a rating of 86. The loss rating goes from 0 (zero) to 310 tons per acre per
year.
The site shall be protected against water and wind erosion potential during construction
until paving operations, landscape installation and permanent erosion controls are
completed. A copy of the NRCS report is included in this report.
B. Storm water Management Controls
Prior to mobilization of equipment on site, installation of flow barriers shall be
completed on the edge of all disturbed areas. Existing inlets shall have sediment filters
installed prior to land disturbance activities, to control conveyance of sediments into
existing streets and storm sewer systems.
Site grading shall include installation of a vehicle tracking pad, a temporary sediment
basin, and a concrete washout basin.
Detention pond, inlet protection shall be installed after the installation of the pond
outlet and removed prior to landscape installation in the detention pond.
The vehicle sediment tracking pad shall be removed prior to paving installation. Inlet
protection shall be removed when installation of flat work and paving has been
completed and the potential for conveyance of construction sediment from the site to
the public ROW has been eliminated. Flow barriers shall be removed after all
landscaping is completed and reseeding is established. Refer to the Sequence of
Construction Activity in this report for additional sequence detail.
i. The site SWMP Administration will be the General Contractor selected for the project
build out.
Christian Brothers Automotive Corporation’s Project Manager’s contact information is
provided below until the General Contractor is selected.
Derrick Rodgers, Project Manager
Cell number: 281-381-2497
Fax number: 281-675-6132
Address: 17725 Katy Freeway, Suite 200, Houston, TX 77094
Email: Derrick.Rodgers@cbac.com
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ii. Sources of Potential Pollutants: Sources are sediment contained in storm water runoff.
Sediment will be controlled by a BMP selection of Fiber Flow Barriers, Inlet Socks,
Vehicle Tracking Control pad, Concrete Washout and site watering.
1. Disturbed and stored soils: The project site disturbance area, will be limited to
approximately 0.79 acres. Typically these sites do not have soil stockpiles, if
there are; the topsoil will be stripped in the disturbance area and stockpiled at
the north end of the lot. BMP measures to control water and wind conveyance
of stored soil’s, sediment shall consist of the following: The stockpile shall have
a flow barrier installed around the perimeter of the toe of slope to control water
based conveyance of sediment and shall also be included in site watering to
prevent and control wind generated conveyance of fugitive dust.
2. Vehicle tracking of sediments: The site will have a single, dedicated access
entrance with a VTC pad. Any tracked sediment on paved City streets will be
removed by sweeping and scraping at the end of day as necessary. An existing
inlet to the north on Academy Court will have sediment protection installed
prior to construction activities and will be inspected on a scheduled basis and
after each storm event.
3. Management of contaminated soils: There are no known contaminated soils on
the site. If contaminated soils are located the project Geotech will be notified to
look at the contaminated area and advise of disposal procedures.
4. Loading and unloading operations: Due to the size of the site, equipment and
materials will be unloaded on the street as much as possible for the project
duration. Any movement of soil from the site will be removed as described in
ii.2.
5. Outdoor storage activities: Due to the site size, building materials shall be
scheduled for delivery as needed to minimize material storage. Landscape
materials shall be scheduled for delivery as needed during installation. Storage
of fertilizers, chemicals or other hazardous materials during project construction
is not anticipated based on previous projects. Any movement of soil from the
site will be removed as described in ii.2. BMP’s for shipping materials such as
pallets, straps, boxes, plastic wrapping etc. shall be disposed of in non-industrial
waste receptacles located near the site entrance at the time of use.
6. Vehicle and equipment maintenance and fueling: Site dirt work will be minor
and short term. Most of the project equipment are rentals and are in good
working order when onsite. Maintenance and fueling as necessary will be
conducted on-site in a designated staging area. The staging area shall have low
dirt berm installed around the perimeter to prevent migration of fluids prior to
clean up should a spill occur. Contaminated soils shall be disposed of properly.
7. Significant dust or particulate generating processes: The site shall be watered
regularly during grading operations. Once grading is complete, Curb and Gutter,
and paving of the parking lot will be completed, further reducing dust or
particulate occurrences. Landscape areas and areas of disturbance outside of
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landscape limits will continue to be watered until landscaping and reseeding is
completed. A wind barrier fence shall be installed if site watering is ineffective
and construction activity cannot be halted. Any disturbed or exposed soil
surface areas that will be inactive for more than 30 days or while vegetation is
being established shall be seeded and or watered to prevent soil loses. A copy of
the Dust Prevention and Control Manual shall be referenced for additional
BMP’s should additional dust prevention and control be necessary in addition to
these methods.
8. Routine maintenance activities involving fertilizers, pesticides, detergents, fuels,
solvents, oils, etc.: It is not anticipated any of these materials will be used for
routine maintenance activities. If necessary these activities will take place in the
designated staging area. Any losses will be swept or otherwise collected and
properly disposed of daily. The staging area shall have low dirt berm installed
around the perimeter to prevent migration of fluids prior to clean up should a
spill occur. Contaminated soils shall be disposed of properly.
9. On-site waste management practices: On-site waste will be collected in
approved rented receptacles located near the construction entrance for ease of
removal.
10. Concrete truck/equipment washing, including the concrete truck chute and
associated fixtures and equipment: A concrete washout area will be provided
and signed near the construction entrance. The Contractor shall be responsible
for any loses outside of the concrete washout area and contacting the supplier
of the violation.
11. Dedicated asphalt and concrete batch plants: THERE WILL BE NO BATCH PLANT
ON SITE.
12. Non-industrial waste sources: These will be provided near the construction
entrance and separated from the construction waste collection containers.
13. Other areas or procedures where potential spills can occur: Saw cutting
activities shall prevent the public from entering the area where dust emissions
occur. Saw cutting shall be temporarily halted during high wind events greater
than 30 mph if operations would result in off-property transport. Equipment
and work area clean up shall use wet wiping, wet sweeping, or vacuuming with
HEPA filtration for equipment and work area clean up to prevent dust to
become airborne during clean up. Slurry clean up shall prevent water used for
dust control or clean up from entering any public right-of-way, storm drainage
facility, or watercourse by using containment, vacuuming, absorption, or other
method to remove the slurry, and dispose of slurry and containment materials
properly.
C. Establishment of Dryland Vegetation
Due to this site being an infill project, there will be minimal disturbance in areas that will
be left in a dryland vegetation state. Areas of slope grading to existing surface, and
Page | 5
areas outside of the landscape limits that have been disturbed shall be re-seeded based
on the Fort Collins, Colorado – Municipal Code, Chapter 12 – Health and Environment
Sections 12-123 through 12-132 and the GUIDELINES FOR REVEGETATION OF
DISTURBED AREAS published by Larimer County. Dryland vegetation reseeding shall
consist of the AREA 1 - Flatlands, Standard Mix. This seed mix shall be installed as stated
in the Guidelines published by Larimer County. Supplemental watering shall be available
if needed to insure establishment in non-landscaped areas. The rest of the areas not
paved or occupied by the building will be landscaped. A copy of the Guidelines for
Revegetation of Disturbed Areas is included in this report.
D. Detailed Sequence of Construction Activities
A sequence of construction activities chart is included with this report and copied onto
the erosion and sediment control plan.
E. Erosion Control Security Calculations
The Calculations for Erosion and Sediment Control Escrow/Security is included with this
report. The sequence is typical of the order stated on the erosion control report and
drawing requirements.
II. References
1. City of Fort Collins, Colorado, Erosion Control Report and Drawings Requirements Accompanying
Document.
2. City of Fort Collins, Colorado, Erosion Control Report and Drawings Submittal Requirements
Check Sheet.
Mobilization Demolition Grading
Utilities
Installation
Flat work
Installation
Vertical
Installation Landscape Demobilization
Best Management Practices (BMPs)
Structural "Installation"
Silt Fence Barriers* N/A N/A N/A N/A N/A N/A N/A N/A
Contour Furrows (Ripping / Disking) N/A N/A N/A N/A N/A N/A N/A N/A
Sediment Trap / Filter N/A N/A N/A N/A N/A
Vehicle Tracking Pad* N/A N/A N/A N/A N/A N/A
Flow Barriers (Wattles)* N/A N/A
Inlet Filter Bags* N/A N/A N/A
Rock Bags* N/A N/A N/A
Terracing N/A N/A N/A N/A N/A N/A N/A N/A
Stream Flow Diversion* N/A N/A N/A N/A N/A N/A N/A N/A
Rip Rap N/A N/A N/A N/A N/A N/A
Collecting Asphalt / Concrete Saw Cutting Waste N/A N/A N/A N/A N/A N/A N/A
*All BMPs to be Removed once Construction is Complete.
Vegetative
Temporary Seeding Planting
Mulching/Sealant
Permanent Seeding Planting
Sod Installation
Rolled Products : Netting/Blankets/Mats
Other:
SEQUENCE OF CONSTRUCTION ACTIVITY
Project: Disturbed Acres: 0.79
EROSION CONTROL BMPs Units
Estimated
Quantity
Unit
Price
Total
Price
LF 850 $2.50 $2,125.00
EA 2 $200.00 $400.00
EA 7 $200.00 $1,400.00
EA 1 $200.00 $200.00
LS 1 $500.00 $500.00
EA 1 $1,000.00 $1,000.00
EA 1 $500.00 $500.00
SF 3180 $2.50 $7,950.00
LS 1 $1,000.00 $1,000.00
LS 1 $1,000.00 $1,000.00
LS 1 $5,000.00 $5,000.00
Sub-Total: $21,075.00
1.5 x Sub-Total: $31,612.50
Amount of security: $31,612.50
Total Acres x Price/acre: $1,975.00
$2,500.00 Sub-Total: $1,975.00
1.5 x Sub-Total: $2,962.50
Amount to Re-seed: $2,962.50
Minimum escrow amount: $3,000.00
Erosion Control Escrow: $31,612.50
Fields in yellow should be amended for this project.
On-Site Waste Management
Temporary Sediment Basin (TSB)
Scour Stop (TRM)
Erosion and Sediment Control Escrow/Security Calculation for
The City of Fort Collins
BMP Amount
Silt Fence (SF) or Straw Waddles (SW)
Vehicle Tracking Control (VTC)
SWMP Administration
Reseeding Amount
Rock Sock (RS)
Inlet Protection Modified (IPM)
Miniumum Escrow Amount
Christian Brothers Automotive 1500 Academy Court
Unit Price of Seeding per acre:
Inlet Protection (IP)
Concrete Washout (CW)
(add all other BMPs for the site in this list)
Final Escrow Amount
Non-Industrial Waste Management
8/30/2017 11:52 AM M:\co-15298 CBA Ft Collins\Reports\Erosion Control Report\Example_Escrow.xls
Erosion Control Report and Drawings
Submittal Requirements Check Sheet
JS 6/2015
Erosion Control Report
Written Analysis of the site including…
Current Developed Conditions
Detailed and Site Specific
Existing Percent Vegetation
Nature and Purpose of Construction
Detailed and Site Specific
Total Disturbed Area (Onsite and Off)
Closest Receiving Waters (Path to those waters)
Rainfall Erodibility & Erosion Sediment Control Methods
Analysis of Temporary & Permanent Mitigation
Methods
Timing (Phases) & Sequence of BMP Installation
Sequence Chart …or…
Separate Sheets for each sequence
Choice of BMPs to minimize sediment transport
Source of Non Stormwater Discharge
Extra Site Data
(Soil Boring/Lab Tests/Groundwater Levels)
Stormwater Management Controls (SWMC)
Description of all SWMC
Appropriate & Priority of all SWMC
Identify the SWMP Administrator
Identify Potential Pollutant Sources
(Identify and Describe the Means of Control)
Disturbed and Stored Soils
Vehicle tracking of sediment
Management of contaminated soils
Loading and unloading operations
Outdoor storage activities
Equipment maintenance and fueling
Significant particulate generating
Routine maintenance activities
On-site waste management
Concrete washing
Dedicated asphalt or concrete batch plants
Non-industrial waste sources (worker trash and
portable toilets)
Other potential spills
Dry land vegetation
Soil Types
Seed Mixes
Soil Amendments
Mulches
Detailed sequence of construction activities
Sequence of all land disturbing activity chart
Categories such as: Soil Stockpiling; Drainage Facility;
Maintenance activities; Sediment basins; temporary
channel stabilization; Seeding; Mulching; etc…
Report Redlines have been corrected from prior submittal
N/A
Erosion Control Plans
Clear and uncluttered plans
General Location Map
22”x34” Drawing
Scale 1”=1000’ to 1”=8000’
Must identify any major construction along the drainage
United 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
Larimer County
Area, Colorado
Christian Brothers Automotive
Natural
Resources
Conservation
Service
June 15, 2017
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
2
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.
3
Contents
Preface.................................................................................................................... 2
Soil Information for All Uses.................................................................................5
Suitabilities and Limitations for Use......................................................................5
Water Management...........................................................................................5
Surface Water Management, System (Water Erosion Potential).................. 5
Soil Properties and Qualities.............................................................................. 10
Soil Erosion Factors........................................................................................10
K Factor, Rock Free.................................................................................... 10
T Factor.......................................................................................................13
Wind Erodibility Index..................................................................................16
References............................................................................................................20
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Soil Information for All Uses
Suitabilities and Limitations for Use
The Suitabilities and Limitations for Use section includes various soil interpretations
displayed as thematic maps with a summary table for the soil map units in the
selected area of interest. A single value or rating for each map unit is generated by
aggregating the interpretive ratings of individual map unit components. This
aggregation process is defined for each interpretation.
Water Management
Water Management interpretations are tools for evaluating the potential of the soil in
the application of various water management practices. Example interpretations
include pond reservoir area, embankments, dikes, levees, and excavated ponds.
Surface Water Management, System (Water Erosion
Potential)
The ratings for Surface Water Management, System are based on the soil
properties that affect the capacity of the soil to convey surface water across the
landscape. Factors affecting the system installation and performance are
considered. Water conveyances include graded ditches, grassed waterways,
terraces, and diversions. The ratings are for soils in their natural condition and do
not consider present land use. The properties that affect the surface system
performance include depth to bedrock, saturated hydraulic conductivity, depth to
cemented pan, slope, flooding, ponding, large stone content, sodicity, surface water
erosion, and gypsum content.
The ratings are both verbal and numerical. Rating class terms indicate the extent to
which the soils are limited by all of the soil features that affect the specified use.
"Not limited" indicates that the soil has features that are very favorable for the
specified use. Good performance and very low maintenance can be expected.
"Somewhat limited" indicates that the soil has features that are moderately
favorable for the specified use. The limitations can be overcome or minimized by
special planning, design, or installation. Fair performance and moderate
maintenance can be expected. "Very limited" indicates that the soil has one or more
features that are unfavorable for the specified use. The limitations generally cannot
5
be overcome without major soil reclamation, special design, or expensive
installation procedures.
Numerical ratings indicate the severity of individual limitations. The ratings are
shown as decimal fractions ranging from 0.01 to 1.00. They indicate gradations
between the point at which a soil feature has the greatest negative impact on the
use (1.00) and the point at which the soil feature is not a limitation (0.00).
The map unit components listed for each map unit in the accompanying Summary
by Map Unit table in Web Soil Survey or the Aggregation Report in Soil Data Viewer
are determined by the aggregation method chosen. An aggregated rating class is
shown for each map unit. The components listed for each map unit are only those
that have the same rating class as that listed for the map unit. The percent
composition of each component in a particular map unit is given so that the user will
realize the percentage of each map unit that has the specified rating.
A map unit may have other components with different ratings. The ratings for all
components, regardless of the map unit aggregated rating, can be viewed by
generating the equivalent report from the Soil Reports tab in Web Soil Survey or
from the Soil Data Mart site. Onsite investigation may be needed to validate these
interpretations and to confirm the identity of the soil on a given site.
Custom Soil Resource Report
6
7
Custom Soil Resource Report
Map—Surface Water Management, System (Water Erosion Potential)
4490700 4490720 4490740 4490760 4490780 4490800 4490820 4490840 4490860
4490700 4490720 4490740 4490760 4490780 4490800 4490820 4490840 4490860
496430 496450 496470 496490 496510 496530 496550
496430 496450 496470 496490 496510 496530 496550
40° 34' 7'' N
105° 2' 32'' W
40° 34' 7'' N
105° 2' 26'' W
40° 34' 1'' N
105° 2' 32'' W
40° 34' 1'' N
105° 2' 26'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 40 80 160 240
Feet
0 10 20 40 60
Meters
Map Scale: 1:863 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
Very limited
Somewhat limited
Not limited
Not rated or not available
Soil Rating Lines
Very limited
Somewhat limited
Not limited
Not rated or not available
Soil Rating Points
Very limited
Somewhat limited
Not limited
Not rated or not available
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: Larimer County Area, Colorado
Survey Area Data: Version 11, Sep 23, 2016
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Apr
28, 2011
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.
Custom Soil Resource Report
Tables—Surface Water Management, System (Water Erosion
Potential)
Surface Water Management, System— Summary by Map Unit — Larimer County Area, Colorado (CO644)
Map unit
symbol
Map unit name Rating Component
name (percent)
Rating reasons
(numeric
values)
Acres in AOI Percent of AOI
53 Kim loam, 1 to 3
percent slopes
Not rated Kim (90%) 0.3 12.5%
Fort Collins (6%)
Stoneham (3%)
Aquic Haplustolls
(1%)
54 Kim loam, 3 to 5
percent slopes
Not rated Kim (90%) 0.7 34.2%
Thedalund (4%)
Stoneham (3%)
Fort Collins (2%)
Aquic Haplustolls
(1%)
60 Larim gravelly
sandy loam, 5
to 40 percent
slopes
Very limited Larim (85%) Water Erosion
(1.00)
0.7 34.4%
Slope (1.00)
Large rock
fragments
(0.48)
101 Stoneham loam,
1 to 3 percent
slopes
Not limited Stoneham (90%) 0.4 18.9%
Totals for Area of Interest 2.1 100.0%
Surface Water Management, System— Summary by Rating Value
Rating Acres in AOI Percent of AOI
Not limited 0.4 18.9%
Very limited 0.7 34.4%
Null or Not Rated 1.0 46.7%
Totals for Area of Interest 2.1 100.0%
Rating Options—Surface Water Management, System (Water
Erosion Potential)
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Custom Soil Resource Report
9
Soil Properties and Qualities
The Soil Properties and Qualities section includes various soil properties and
qualities displayed as thematic maps with a summary table for the soil map units in
the selected area of interest. A single value or rating for each map unit is generated
by aggregating the interpretive ratings of individual map unit components. This
aggregation process is defined for each property or quality.
Soil Erosion Factors
Soil Erosion Factors are soil properties and interpretations used in evaluating the
soil for potential erosion. Example soil erosion factors can include K factor for the
whole soil or on a rock free basis, T factor, wind erodibility group and wind erodibility
index.
K Factor, Rock Free
Erosion factor K indicates the susceptibility of a soil to sheet and rill erosion by
water. Factor K is one of six factors used in the Universal Soil Loss Equation
(USLE) and the Revised Universal Soil Loss Equation (RUSLE) to predict the
average annual rate of soil loss by sheet and rill erosion in tons per acre per year.
The estimates are based primarily on percentage of silt, sand, and organic matter
and on soil structure and saturated hydraulic conductivity (Ksat). Values of K range
from 0.02 to 0.69. Other factors being equal, the higher the value, the more
susceptible the soil is to sheet and rill erosion by water.
"Erosion factor Kf (rock free)" indicates the erodibility of the fine-earth fraction, or
the material less than 2 millimeters in size.
Custom Soil Resource Report
10
11
Custom Soil Resource Report
Map—K Factor, Rock Free
4490700 4490720 4490740 4490760 4490780 4490800 4490820 4490840 4490860
4490700 4490720 4490740 4490760 4490780 4490800 4490820 4490840 4490860
496430 496450 496470 496490 496510 496530 496550
496430 496450 496470 496490 496510 496530 496550
40° 34' 7'' N
105° 2' 32'' W
40° 34' 7'' N
105° 2' 26'' W
40° 34' 1'' N
105° 2' 32'' W
40° 34' 1'' N
105° 2' 26'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 40 80 160 240
Feet
0 10 20 40 60
Meters
Map Scale: 1:863 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
.02
.05
.10
.15
.17
.20
.24
.28
.32
.37
.43
.49
.55
.64
Not rated or not available
Soil Rating Lines
.02
.05
.10
.15
.17
.20
.24
.28
.32
.37
.43
.49
.55
.64
Not rated or not available
Soil Rating Points
.02
.05
.10
.15
.17
.20
.24
.28
.32
.37
.43
.49
.55
.64
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Table—K Factor, Rock Free
K Factor, Rock Free— Summary by Map Unit — Larimer County Area, Colorado (CO644)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
53 Kim loam, 1 to 3 percent
slopes
.32 0.3 12.5%
54 Kim loam, 3 to 5 percent
slopes
.32 0.7 34.2%
60 Larim gravelly sandy
loam, 5 to 40 percent
slopes
.24 0.7 34.4%
101 Stoneham loam, 1 to 3
percent slopes
.32 0.4 18.9%
Totals for Area of Interest 2.1 100.0%
Rating Options—K Factor, Rock Free
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Layer Options (Horizon Aggregation Method): All Layers (Weighted Average)
T Factor
The T factor is an estimate of the maximum average annual rate of soil erosion by
wind and/or water that can occur without affecting crop productivity over a sustained
period. The rate is in tons per acre per year.
Custom Soil Resource Report
13
14
Custom Soil Resource Report
Map—T Factor
4490700 4490720 4490740 4490760 4490780 4490800 4490820 4490840 4490860
4490700 4490720 4490740 4490760 4490780 4490800 4490820 4490840 4490860
496430 496450 496470 496490 496510 496530 496550
496430 496450 496470 496490 496510 496530 496550
40° 34' 7'' N
105° 2' 32'' W
40° 34' 7'' N
105° 2' 26'' W
40° 34' 1'' N
105° 2' 32'' W
40° 34' 1'' N
105° 2' 26'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 40 80 160 240
Feet
0 10 20 40 60
Meters
Map Scale: 1:863 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
1
2
3
4
5
Not rated or not available
Soil Rating Lines
1
2
3
4
5
Not rated or not available
Soil Rating Points
1
2
3
4
5
Not rated or not available
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: Larimer County Area, Colorado
Survey Area Data: Version 11, Sep 23, 2016
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Apr
Table—T Factor
T Factor— Summary by Map Unit — Larimer County Area, Colorado (CO644)
Map unit symbol Map unit name Rating (tons per acre
per year)
Acres in AOI Percent of AOI
53 Kim loam, 1 to 3 percent
slopes
5 0.3 12.5%
54 Kim loam, 3 to 5 percent
slopes
5 0.7 34.2%
60 Larim gravelly sandy
loam, 5 to 40 percent
slopes
2 0.7 34.4%
101 Stoneham loam, 1 to 3
percent slopes
5 0.4 18.9%
Totals for Area of Interest 2.1 100.0%
Rating Options—T Factor
Units of Measure: tons per acre per year
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Lower
Interpret Nulls as Zero: No
Wind Erodibility Index
The wind erodibility index is a numerical value indicating the susceptibility of soil to
wind erosion, or the tons per acre per year that can be expected to be lost to wind
erosion. There is a close correlation between wind erosion and the texture of the
surface layer, the size and durability of surface clods, rock fragments, organic
matter, and a calcareous reaction. Soil moisture and frozen soil layers also
influence wind erosion.
Custom Soil Resource Report
16
17
Custom Soil Resource Report
Map—Wind Erodibility Index
4490700 4490720 4490740 4490760 4490780 4490800 4490820 4490840 4490860
4490700 4490720 4490740 4490760 4490780 4490800 4490820 4490840 4490860
496430 496450 496470 496490 496510 496530 496550
496430 496450 496470 496490 496510 496530 496550
40° 34' 7'' N
105° 2' 32'' W
40° 34' 7'' N
105° 2' 26'' W
40° 34' 1'' N
105° 2' 32'' W
40° 34' 1'' N
105° 2' 26'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 40 80 160 240
Feet
0 10 20 40 60
Meters
Map Scale: 1:863 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
0
38
48
56
86
134
160
180
220
250
310
Not rated or not available
Soil Rating Lines
0
38
48
56
86
134
160
180
220
250
310
Not rated or not available
Soil Rating Points
0
38
48
56
86
134
160
180
220
250
310
Not rated or not available
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
Table—Wind Erodibility Index
Wind Erodibility Index— Summary by Map Unit — Larimer County Area, Colorado (CO644)
Map unit symbol Map unit name Rating (tons per acre
per year)
Acres in AOI Percent of AOI
53 Kim loam, 1 to 3 percent
slopes
86 0.3 12.5%
54 Kim loam, 3 to 5 percent
slopes
86 0.7 34.2%
60 Larim gravelly sandy
loam, 5 to 40 percent
slopes
56 0.7 34.4%
101 Stoneham loam, 1 to 3
percent slopes
48 0.4 18.9%
Totals for Area of Interest 2.1 100.0%
Rating Options—Wind Erodibility Index
Units of Measure: tons per acre per year
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Custom Soil Resource Report
19
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
20
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
21
GUIDELINES FOR REVEGETATION OF DISTURBED AREAS
I. GENERAL:
Re-seeding of disturbed areas to establish a viable vegetative cover is often the most effective
method for long-term control of erosion. Proper selection of species to be used will maximize
the success of the project. In most of the outlying areas of the County, selection of appropriate
native grasses is recommended. Introduced species, such as smooth brome and crested
wheat, are not recommended unless the area to be re-seeded is in an area of the county that
is dominated by such species. This could be in areas where introduced aggressive pasture
grasses have been established and are likely to replace other species over time. Appropriate
species for the seed mix should be determined by a knowledgeable specialist after adequate
reconnaissance and inventory of the site. Species selection for sites in areas under the
jurisdiction of other agencies, such as U.S. Forest Service, Colorado State Forest, or BLM,
should be done in consultation with the agency involved. The specialist should also specify
appropriate mulching and soil amendment parameters for the re-seeded areas.
II. TOPSOIL:
Retention of topsoil, when a site is to be disturbed, is perhaps the most critical aspect of site
reclamation. It is also the initial step to be accomplished when the work begins. Topsoil is the
uppermost horizon of soil and contains organic material which often gives it a dark brown
color. In addition to the organic matter, topsoil contains nutrients, microbes and a seed bank
from the plants existing at the site. If these can be saved and replaced when the work is done,
the chances of a successful re-establishment of vegetative cover is enhanced manifold. The
following guidelines will optimize the topsoil retention and redistribution processes when areas
are disturbed during the course of typical projects.
1) Storage: Topsoil should be removed and stockpiled whenever practical for redistribution
over the disturbed area to provide a viable seedbed. This can be accomplished by
removing the topsoil and storing in piles on the perimeter of the area to be disturbed or
wind rowing the topsoil along the outside edge of areas such as road cuts. The topsoil can
then be redistributed over the disturbed areas in preparation for seeding activities. When
1
soil is to be stockpiled for a period exceeding six months, the stockpile should be seeded to
appropriate grasses. This will protect the soil from erosion and will maintain the existing
microorganisms and other soil constituents through natural nutrient cycling processes.
3) Redistribution: Clean, uncontaminated topsoil should be reapplied to a depth of 4-6 inches.
Soil replacement will minimize the need for soil amendments and the seed will be placed in
an optimum medium for germination and establishment. If topsoil stockpiling is not
possible, or is insufficient to attain the 4-6 inch depth, the material to be used as soil should
be amended to replace organic material, nutrients and other soil characters as needed.
Composted manure, fertilizers, and other amendments, as prescribed by the Specialist,
should be applied and incorporated into the top 6 inches of material. In all cases adequate
sampling should be accomplished for soil testing at the Colorado State University Soils Lab
or a laboratory of comparable capabilities. Recommendations for soil amendments are
reported with the results and should be followed. To insure proper recommendations are
received, it is necessary to describe the type of seeding application intended (eg: native
range grasses, cereal crops, irrigated pasture grasses, etc.) when presenting the soil
samples for analysis.
3) Soil sampling: A composite sample should be collected for analysis using a spade or soil
auger. No galvanized tools should be used. Sampling tools should be clean and free of
rust. The composite should combine no fewer than three subsamples taken from the top 6
inches of soil material. The number of composite samples will depend upon the size of the
area and homogeneity of soil material. Appropriate number of samples should be
determined by the Specialist. If more than one composite is collected, the location of areas
represented should be recorded and marked in the field. A composite sample should
contain approximately one quart of material for analysis. The sample should be placed in a
clean one quart polyethylene bag and sealed. Samples must be delivered to the lab within
24 hours of collection if at all feasible. If samples cannot be delivered within 24 hours, the
sample should be air-dried for 48 hours in a dust free environment.
III. FERTILIZER RECOMMENDATIONS:
Fertilizers should be added only to the extent necessary. Native grasses are adapted to soils
with low nutrient content and often require minimal fertilization to do well. If sufficient topsoil is
stockpiled and redistributed, it will often retain adequate amounts of nutrients and microbes for
good seed germination and establishment of native range grasses.
Native grasses respond best to slow-release organic fertilizers, such as Biosol™ or an
equivalent, and these are preferred for soil amendment in cases where native species are
seeded. Over application of commercial fast-release fertilizers will encourage weed growth in
these applications. If a commercial fertilizer is to be used, its formula should be based upon
analysis of the existing soil or growing medium. This analysis can be accomplished by
sampling the soil to be seeded and having it analyzed for nutrient composition by a qualified
lab. If this is not possible, 11-48-0 commercial fertilizer is recommended.
V. SEED BED PREPARATION:
2
The soil to which the seeds are to be applied should be in a firm condition, but not so firm or
compacted as to inhibit infiltration. Loose soils may require light rolling. If the surface is
compacted to the point to inhibit infiltration, the top 4-6 inches should be harrowed or tilled
before rolling. The intent is to accommodate seeding to proper depth and to provide sufficient
infiltration of precipitation for soil storage of moisture and to decrease runoff and erosion. On
slopes, harrowing along contours should be accomplished to slow runoff and promote
infiltration. Depth of harrowing or tilling should be determined by depth of topsoil applied and
should be set to minimize intermixing of this topsoil layer and the underlying subsoil or spoil
material.
V. METHODS OF SEEDING:
Seeds must be placed at the appropriate depth in the soil to optimize germination. In general,
seeds should be placed ¼” to ½” deep in the soil. There are several acceptable methods to
accomplish efficient seeding on disturbed sites.
1. Drill Seeding: Drill seeding is normally considered to be the most efficient and
effective seeding procedure. Seed should be drilled to a depth of ¼” to ½” in depth.
Drill seeding is very effective and economic on large relatively flat areas (up to 3:1
slope). Drilling depths should be determined by recommended depths for the species
selected for the project mix.
2. Hand/Mechanical Broadcast Seeding: Hand or mechanical broadcast seeding can be
very effective, with proper technique, and is more practical and economic for small or
hard to reach areas. The seedbed is tilled or harrowed prior to seeding. After
broadcasting the seed, the seedbed should be lightly harrowed or chain dragged to
fully incorporate the seed with the soil. Seeding rates shall be double the
recommended drill-seeding rate.
3. Hydro-seeding: Hydro-seeding is an efficient means of applying seed to steep areas
(>3:1). This method has the disadvantage of a less effective means of achieving
proper soil to seed contact. The operation should be done as a separate operation
from hydro-mulching, although it is acceptable to add a small amount of mulch in the
seed slurry to bind to the soil and allow visible evidence of covered areas. Seeding
rates should be double the recommended drill-seeding rate.
VI. MULCHING:
Upon completion of seeding and fertilizing operations, mulch should be applied to the soil
surface. Mulch will deter erosion during the establishment of vegetation and will serve to
conserve moisture and reduce surface compaction or crusting. The following mulching
techniques are acceptable:
3
1. Crimped straw or hay: The material should be native grass hay or cereal grain straw.
Native hay should be certified weed free. At least 50 percent of the mulch, by weight,
should be ten inches or more in length. Hay or straw is crimped in place with a
mechanical crimper made for such purposes or using a farm-type disc plow set
straight with adequate weight to crimp the material to a depth of approximately 4
inches. The hay or straw should be applied at a minimum rate of 2000 lbs. per acre.
Slopes exceeding 5:1 or areas where windy conditions are likely should be mulched at
4000 lbs. per acre.
2. Hydro-mulch: Hydro-mulch, comprised of wood fiber, should be applied at a rate of
1000 to 2000 lbs. per acre, depending on slope conditions. Hydro-mulching should be
limited to areas that exhibit slopes too steep to allow safe operation of drill-seeding
equipment or are otherwise inaccessible to other means. Slopes greater than 3:1
require addition of tackifying agents to the slurry to maximize retention of the mulch on
the soil surface. These agents should be mixed as per manufacturers’ specifications
to achieve the desired coverage for the topography of the site.
3. Erosion control blankets: Erosion control blankets should be used in conditions
where steep slopes (>3:1) with relatively smooth surface soil surface are encountered
or areas where concentrated flows are expected, such as drainage channels. These
blankets come in a number of configurations and weights. Manufacturer’s
specifications should be consulted for appropriate application. These blankets are to
be adequately anchored in place with staples as per manufacturers’ specifications.
Blankets are not effective on rough, uneven or rocky surfaces since adequate
continuous contact with the soil cannot be attained.
4. Bonded Fiber Matrix Systems: In cases where rough, uneven, or rocky surfaces
preclude the use of blankets, a bonded fiber matrix system should be specified.
These systems involve the hydraulic application of a fiber and tackifier mulch in a
continuous cover and are very effective on steep slopes if properly applied.
Manufacturers’ specifications shall be consulted for the appropriate application rate for
the site circumstances.
VII. SEED MIX SPECIFICATIONS:
Larimer County is divided into three distinct areas of topography and climatic conditions
(Figure 1). Area I consists of flatlands, Area II consists of the foothills area, and Area III the
mountainous areas of the County. The tables attached illustrate native grass species that are
best adapted to each particular area. Seed mixes should be comprised of choices from the
appropriate table for the site to be seeded. Seed mixes should be designed to accomplish an
application rate of 65 seeds per square foot, on a PLS* basis. A minimum of four species
should be specified for mixes and a mix of cool and warm weather species used if possible. A
standard mix is shown for each area as well as other representative grasses. Substitutions or
* PLS = Pure Live Seed (percentage of live seed per unit calculated by multiplying the germination rate (in %) by the purity
% for each species.
4
additions to the standard mix should come from this list. It should be noted that the seeding
rates from the tables are for drill seeding specifications. Broadcast seeding or hydraulic
seeding rates should be specified at twice this rate to assure proper germination rates.
Custom mixes may be appropriate for localized projects. Instances may be in areas within U.
S. Forest Service jurisdiction or other sensitive areas where use of appropriate native species,
particular to that area, is mandatory or desired. Such mixes should be designed by the
Specialist or other knowledgeable party to meet the criteria.
For added interest or a more “naturalized” plant establishment, wildflowers and other native
forbs may be added. Some species of native wildflowers are easily established and perennial
species will establish extensive root systems that enhance erosion control and soil
stabilization. A few native wildflower species are suggested in the tables and can be added to
the seed mix.
VII. SLOPE CONFIGURATION AND PREPARATION:
Cut and fill slopes should be designed and constructed to maximize stability and optimize
conditions for reseeding as much as is practical. In general, cut slopes in soil or loose material
should be constructed to be no steeper than 3:1 unless site constraints limit this configuration.
Fill slopes should be no steeper than 3:1. All slopes should be scarified along contours for the
final dressing to retard erosion and optimize seed placement. Tracking with dozers, or other
tracked equipment, up and down slopes is acceptable placing cleat marks parallel to contours.
Blading up and down slopes is not acceptable for final dressing of the slope. On slopes where
regular farm equipment can be used safely, harrowing of the surface along contours is an
excellent method. The surface should be left in a slightly roughened condition with harrow or
cleat marks along contours. Seeding operations should be completed as soon as possible to
stabilize the surface while the soil is still in optimum condition to accept seed, amendments
and mulch. If seasonal conditions are inappropriate for seeding, the slope may require interim
mulching to control erosion until the proper conditions exist for successful seed placement.
VIII. ROAD-SIDE STORM WATER CHANNELS:
Reconstruction or regrading of roadside channels is an integral part of most projects in which
the Engineering Department is involved. Timely revegetation of these channels is critical for
the ongoing viability of these channels as conduits for storm water. By definition, roadside
storm water channels are often submitted to concentrated flows that make it a challenge to
establish adequate grass cover to optimize control of erosion and to prevent sedimentation of
the storm water flows. It is important to protect the soil surface of the channel adequately for a
time sufficient to allow germination and establishment of the seeded grasses. Geometry of the
channel should be designed and constructed to maintain side slopes of no greater than 3:1 if
at all possible. In cases where continuous flows are anticipated, or intermittent large flows are
likely during the establishment period, the bare soil should be adequately mulched or covered
with appropriate erosion control blankets after seeding. If hydro mulch is used, it should be
applied at 3,000 lb/ac with tackifier added at the manufacturer’s recommended rate. It is often
advisable to cover the bottom and sides of the channel, at least to the anticipated high-water
5
flow, with blankets. Composition and construction of specified erosion control blankets will
depend upon geometry of the channel and expected flow rates. Manufacturer’s specifications
should be consulted to determine the appropriate weight and composition of the blankets.
Manufacturer’s installation instructions for the proper staple pattern, overlap and blanket
placement should be followed. Details of installation should be included in the plans if the
contractor is expected to install the blankets. Installation should be monitored and inspected to
insure correct application.
To repeat, quick establishment of grass cover is often critical in these situations. Although the
native species mixes detailed in the tables attached are often preferable or mandated in
certain areas, additions of species noted for quick establishment may be necessary to stabilize
the soil. In many of the plains locations the surrounding area may be predominantly pasture or
farmland. In these cases it is appropriate to seed the channel to species such as smooth
brome or tall fescue for quick establishment and vigorous growth. Seed at the rate of 30 lb/ac,
PLS. In other areas, where native seeding is preferred, addition of annual ryegrass or hard
fescue may be appropriate. In these cases the species should make up about 10-15% of the
total mix. If circumstances preclude use of non-native species in the mix, other mechanical or
chemical means of soil stabilization will be necessary to allow sufficient time for seed
germination and establishment of the grass. This could mean installation of erosion control
blankets or addition of chemical additives to maintain a stable soil matrix for at least a year.
6
AREA I -Flatlands
Standard Mix:
Species Scientific name Variety % of mix lb/ac, PLS
Buffalograss Buchloe dactyloides Texoka 44.4 8.4
Western wheatgrass Pascopyrum smithii Arriba 22.8 4.3
Slender wheatgrass Elymus trachycaulus San Luis 15.9 3.0
Sideoats grama Bouteloua curtipendula Vaughn 13.2 2.5
Blue grama Bouteloua gracilis Hachita 3.2 0.6
Sand dropseed Sporobolus
cryptandrus
0.5 0.1
Seeding rate =18.9 lb/ac, PLS
Representative species:
Species Scientific name Seeds per pound
Slender wheatgrass Elymus trachycaulum 159,000
Western wheatgrass Pascopyrum smithii 110,000
Blue grama Bouteloua gracilis 825,000
Buffalograss Buchloe dactyloides 56,000
Sideoats grama Bouteloua curtipendula 191,000
Little bluestem Schizachyrium scoparium 260,000
Sand bluestem Andropogon hallii 113,000
Sand dropseed Sporobolus cryptandrus 5,298,000
Green needlegrass Stipa viridula 181,000
Alkali sacaton* Sporobolus airoides 1,758,000
Inland saltgrass* Distichlis stricta 520,000
Switchgrass* Panicum virgatum 389,000
*Species adapted to wet, alkaline habitat
Wildflower species:
Yarrow Prairie coneflower
Perennial gaillardia Plains coreopsis
Blue flax Plains wallflower
Lance-leaved coreopsis Prairie aster
Scarlet globemallow Annual gaillardia
7
AREA II - Foothills
Standard Mix:
Species Scientific name Variety % of mix lb/ac, PLS
Western wheatgrass Pascopyrum smithii Arriba 30.1 4.3
Big bluestem Andropogon gerardi Pawnee 25.2 3.6
Green needlegrass Stipa viridula Lodorm 18.2 2.6
Sideoats grama Bouteloua
curtipendula
Vaughn 17.5 2.5
Sheep fescue Festuca ovina Covar 4.8 0.7
Blue grama Bouteloua gracilis Hachita 4.2 0.6
Seeding rate = 14.3 lb/ac,
PLS
Representative species:
Species Scientific name Seeds per pound
Western wheatgrass Pascopyrum smithii 110,000
Bluebunch wheatgrass Pseudoroegneria spicatum 140,000
Green needlegrass Stipa viridula 181,000
Needle and thread Stipa comata 115,000
Big bluestem Andropogon gerardi 130,000
Little bluestem Schizachyrium scoparium 260,000
Sheep fescue Festuca ovina 680,000
Sandberg bluegrass Poa sandbergii 925,000
Canby bluegrass Poa canbyi 926,000
Indian ricegrass Oryzopsis hymenoides 141,000
Blue grama Bouteloua gracilis 825,000
Sideoats grama Bouteloua curtipendula 191,000
Wildflower species:
Pasque flower Indian paintbrush
Perennial gaillardia Blue flax
Yarrow Penstemon spp.
Sulphur flower Harebell
Plains wallflower Low fleabane
8
AREA III - Mountains
Standard Mix:
Species Scientific name Variety % of mix lb/ac, PLS
Mountain brome Bromus marginatus Bromar 33.1 5.2
Western wheatgrass Pascopyrum smithii Arriba 27.4 4.3
Slender wheatgrass Elymus
trachycaulus
San Luis 19.2 3.0
Annual ryegrass* Lolium multiflorum 12.7 2.0
Sheep fescue Festuca ovina Covar 4.4 0.7
Canby bluegrass Poa canbyi Canbar 3.2 0.5
Seeding rate = 15.7 lb/ac, PLS
*Introduced species for quick cover. May not be acceptable in special areas.
Representative species:
Species Scientific name Seeds per pound
Mountain brome Bromus marginatus 90,000
Canby bluegrass Poa canbyi 926,000
Sheep fescue Festuca ovina 680,000
Slender wheatgrass Elymus trachycaulus 159,000
Western wheatgrass Pascopyrum smithii 110,000
Sandberg bluegrass Poa sanbergii 925,000
Bluebunch wheatgrass Pseudoroegneria spicata 140,000
Prairie junegrass Koleria cristata 2,315,000
Idaho fescue Festuca idahoensis 450,000
Alpine bluegrass Poa alpina 1,000,000
Timothy Phleum pratense 1,300,000
Blue grama Bouteloua gracilis 825,000
Wildflower species:
Pasque flower Yarrow
Bellflower Fleabane daisy
Arrowleaf balsa Dame’s rocket
Colorado blue columbine Penstemon spp.
Wallflower Rocky Mountain iris
9
NON-NATIVE SEEDING OF ROADSIDE DITCHES IN
PLAINS AND FOOTHILLS AREAS*
Species Scientific name % of Mix, PLS Lb/ac, PLS
Smooth brome Bromus inermis 41 12.4
Tall fescue, Grande Festuca arundinacea 21 6.3
Western wheatgrass Pascopyrum smithii 21 6.3
Annual ryegrass Lolium multiflorum 17 5.0
30.0
* This seed mix is appropriate where quick germination and establishment are important and native seeding is not
an issue (e.g., areas in agricultural settings where introduced pasture grasses are common).
10
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: Larimer County Area, Colorado
Survey Area Data: Version 11, Sep 23, 2016
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Apr
28, 2011
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.
Custom Soil Resource Report
18
28, 2011
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.
Custom Soil Resource Report
15
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: Larimer County Area, Colorado
Survey Area Data: Version 11, Sep 23, 2016
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Apr
28, 2011
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.
Custom Soil Resource Report
12
8
Ditches, Extended Detention, Culverts, Storm sewers…
Basins Divided into Topography
Erosion Control Plans
22”x34” Drawing
Scale 1”=20’ to 1”=200’
Sequence Plans indicating timing, extent and location, of
the temporary BMPs
Standard construction details and notes of erosion and
sediment control measures
Job-specific construction details and notes of erosion and
sediment control measures
List vegetative specification from either Urban Drainage
Manual, or alternative sources.
List structural specification from the Urban Drainage
Manual, or other specifications and a justification if an
alternative is sought after.
A construction detail for ALL proposed construction BMPs.
The ‘standard erosion and sediment control notes’ are
included on the plan set.
Plan Redlines have been corrected from prior submittal
N/A
Erosion control security calculations
BMP Amount Calculated
All BMPs Calculated
Estimated Quantity and Price are realistic
1.5 Times the estimated BMP controls
Reseeding Amount Calculated
All Disturbed Area Calculated
Estimated Area and Price are realistic
1.5 Times the estimated reseeding
Higher of the BMP, Reseeding, or Minimum Selected
(Final Erosion Control Number needs to be sent to City Engineer
for the Project in order to be reflected in the Development
Agreement)
Escrow Redlines have been corrected from prior submittal
N/A