HomeMy WebLinkAboutNIX FARM NATURAL AREAS FACILITY - FDP - FDP180002 - SUBMITTAL DOCUMENTS - ROUND 1 - PROJECT SUBMITTAL AND RESUBMITTALDEVELOPMENT REVIEW:
APPLICATION FORM
Community Development & Neighborhood Services – 281 N College Ave – Fort Collins, CO 80522-0580
Project Information
Project Name:_____________________________________________
Project Description (Choose type of request from the list on the back):
_________________________________________________________
_________________________________________________________
_________________________________________________________
Location Description/Project Address:_________________________
_________________________________________________________
_________________________________________________________
Major Cross Streets: _______________________________________
Zone District:______________________________________________
Parcel Number: ____________________________________________
Building/Unit Information
Residential:_________ ___________________________Square Feet
Commercial:____________________________________Square Feet
Industrial:______________________________________Square Feet
Building Floor Area Ratio:___________________________________
Platted Area:______________________________________________
Number of Units:
Single Family Attached:______Single Family Detached: __________
Two Family:________________Multi-Family:____________________
Total Number of Bedrooms Rented Separately:_________________
Dates:
Conceptual Review Meeting Date_____________________________
Neighborhood Meeting Date_________________________________
Hearing Type______________________________________________
Site/Area Information
Residential Area:_____________ _____Sq. Ft. ____________Acres
Commercial Area:____________ _____ Sq. Ft. ____________Acres
Industrial Area:_____________ ______ Sq. Ft. ____________Acres
Mixed Use Area:_____________ ______Sq. Ft. ___________Acres
Right of Way Area: _________________ Sq. Ft. ___________Acres
Parking and Drive Area: _____________ Sq. Ft. ___________Acres
Stormwater Detention Area:__________Sq. Ft. ___________Acres
Landscape Area: ___________________Sq. Ft. ___________Acres
Open/Other Areas: __________________Sq. Ft. __________Acres
Gross Area:________________________Sq. Ft. ___________Acres
Floor Area Ratio:_________________________________________
Gross Density:________________Net Density ________________
Owner Information
Name:__________________________________________________
Address:________________________________________________
________________________________________________________
City:__________________State:________________Zip:__________
Phone:_________________Email:___________________________
Applicant Information
Name:__________________________________________________
Organization Name: ______________________________________
Contact:_________________________________________________
Address:________________________________________________
City___________________State:________________Zip:_________
Phone:_________________Email:___________________________
Preferred Method of Contact: ______________________________
For Office Use Only
Date Submitted ________________ Current Planning File #_________________ Planner______________________
ð CERTIFICATIONMUSTBESIGNED.ï
CERTIFICATION
Revised November 18, 2014 2 PDP Submittal Requirements
Type of Request
Please indicate the type of application submitted by checking the box preceding the appropriate request(s).
Additional handouts are available explaining the submittal requirements for each of the following review
processes.
Annexation Petition with Initial Zoning REQUESTED ZONE: _______________________________
Fee $1,188.00 + $50.00 sign posting fee + $.75 for each APO label
Rezoning Petition REQUESTED ZONE: _____________________________
Fee $977.00 + $50.00 sign posting fee
Overall Development Plan (ODP)
Fee: $1,599.00 + $50.00 sign posting fee + $.75 for each APO label
Project Development Plan (PDP) without Subdivision Plat (also Wireless Tele-communication Facilities)
Fee: $3,887.00 + $50.00 sign posting fee + $.75 for each APO label
Project Development Plan (PDP) with Subdivision Plat
Fee: $5,879.00 + $50.00 sign posting fee + $.75 for each APO label
Final Plan without Subdivision Plat
Fee: $1,000.00
Final Plan with Subdivision Plat
Fee: $1,000.00
Modification of Standards/Text and Map Amendment
Fee: $200.00+ ($50.00 sign posting fee + $.75 for each APO label for Modification of Standards only)
Basic Development Review
Fee: $200.00
Major Amendment
Fee: $3,206.00 + $50.00 sign posting fee + $.75 for each APO label
Non-Conforming Use Review
Fee: $1,389.00
Vacation of ROW or Easement
Fee: $5.00 per sheet of filing document
Small Project Fees
Fee: Varies-Check with the Current Planning Department
Street Name Change
Fee: $5.00
Extension of Final Approval
Fee: $566.00
Site Plan Advisory Review
NO FEE
Addition of Permitted Use
Fee: $500.00 + $50.00 sign posting fee + $.75 for each APO label
Transportation Development Review Fee Date Received/ Paid _________
Total Amount Paid _________
Project Name: _________________________________________________
Project Location: _______________________________________________ Date: ______________
Type of Submittal
Please indicate the type of application submitted by checking the box
preceding the appropriate request(s).
Fee structure amount due
Overall Development Plan (ODP) $500 each ______
Final Development Plan (FDP)
This fee includes 2 rounds of review $1000 each ______
Additional round of review $ 500 each ______
Annexation $20 X ___ acres = ____ + $250 = ______
The maximum fee for each annexation document/ filing shall be $2,000
Minor Amendment $158 each ______
Major Amendment $2,500 each ______
Re-zone $200 each ______
Modification to Land Use Code $200 each ______
Wireless Telecommunication Equipment (WTE) $65 each ______
Road Projects ______ acres (of roadway) X $3,500 = ______
Vacation of Easement(s) *** # of vacations ___ X $400 = ______
Vacation of Right(s)-of-Way *** # of vacations ___ X $800 = ______
Dedication of Easement(s) and/or Right(s)-of-Way ***
# of dedications ___ X $250 = ______
Project Development Plan (PDP) or Basic Development Review
Project requiring Transportation Services Review and/or utility plan review.
This fee includes 3 rounds of review.
Detached Single Family $160 per unit
_____ # of units X $160 = ______
Multifamily or other residential units $115 per unit
_____ # of units X $115 = ______
Commercial, Industrial, Retail, and/or Non residential
building square footage $0.25 per square foot
______sq ft X $0.25 = ______
Size of the development (area being platted or if not being
platted size of parcel accompanying all development
improvements) $250 per acre ______ acres X $ 250 = ______
Project fee $2,000 each $2,000
Total of above amounts __________
If this fee amount exceeds $30,000 then the fee amount shall be adjusted with the
following formula: $30,000 + ½ (the amount over 30,000 ________) = _________
The maximum fee for any residential ONLY project shall be $500 per residential unit.
This check should be used to verify the fee amount (does not apply to mixed-use
developments). PDP fee shall be the lesser of this amount or the above calculated
amount. ______ # of residential units X $500 = _________
If this fee amount equals or exceeds $65,000 then the City Manager shall have the ability
to reduce the fee amount.
Reduction for affordable housing – a copy of the City letter certifying/ authorizing the
affordable housing shall be provided with this application. Amount of reduction to be
applied ______ ___________
Total owed for PDP _________
2012 form
General Information:
Owners Name(s): ____________________________
___________________________________________
Street address: _______________________________
___________________________________________
City/State/Zip: _______________________________
Telephone: _______________ Fax: ______________
Applicants/ Consultants Firm Name: ___________
Community Development and
Neighborhood Services
281 North College Avenue
PO Box 580
Fort Collins, CO 80522
970.221.6750
970.224.6134 - fax
fcgov.com/developmentreview
January 02, 2018
Stephen Steinbicker
Architecture West, LLC
160 Palmer Dr
Fort Collins, CO 80525 COMMENT RESPONSES – 1.22.18
RE: Nix Farm Natural Areas Facility, MJA160004, Round Number 3
Please see the following summary of comments from City staff and outside reviewing
agencies for your submittal of the above referenced project. If you have questions about
any comments, you may contact the individual commenter or direct your questions through
the Project Planner, Ryan Mounce, at 970-224-6186 or rmounce@fcgov.com.
Comment Summary:
Department: Engineering Development Review
Contact: Katie Andrews, 970-221-6501, kandrews@fcgov.com
Topic: General
Comment Number: 2 Comment Originated: 11/16/2016
1/9/2017: Engineering is ready for the project to go to hearing. Alignments and
a development agreement can be finalized after hearing. 11/16/2016: The
process for dedicating easements/alignments by separate document can be
found here: http://www.fcgov.com/engineering/devrev.php An agreement will
need to be finalized prior to MJA approval.
RESPONSE: The alignment descriptions have been prepared and we are awaiting the dedication language from the
attorney. We will send for review once complete.
Department: Environmental Planning
Contact: Rebecca Everette, 970-416-2625, reverette@fcgov.com
Topic: General
Comment Number: 5 Comment Originated: 12/18/2017
12/18/2017: FOR FINAL PLAN: Please replace the native seeding notes on
sheet L.2 with the following:
RESPONSE: The additional seeding notes were added; the notes had to be shifted to sheet L.1 in order to
fit. The notes are a mixture of Natural Area’s Notes, Torrey Design Studio Notes and these notes from
Environmental Planning.
NATIVE SEED MIX NOTES
1. PREPARE SOIL AS NECESSARY AND APPROPRIATE FOR NATIVE
SEED MIX SPECIES THROUGH AERATION AND ADDITION OF
AMENDMENTS, THEN SEED IN TWO DIRECTIONS TO DISTRIBUTE SEED
EVENLY OVER ENTIRE AREA.
2. IF CHANGES ARE TO BE MADE TO SEED MIX BASED ON SITE
CONDITIONS THEN APPROVAL MUST BE PROVIDED BY CITY
ENVIRONMENTAL PLANNER OR NATURAL AREAS STAFF.
3. APPROPRIATE NATIVE SEEDING EQUIPMENT WILL BE USED
(STANDARD TURF SEEDING EQUIPMENT OR AGRICULTURE EQUIPMENT
SHALL NOT BE USED).
4. DRILL SEED APPLICATION RECOMMENDED PER SPECIFIED
APPLICATION RATE TO NO MORE THAN ½ INCH DEPTH. FOR
BROADCAST SEEDING INSTEAD OF DRILL SEEDING METHOD DOUBLE
SPECIFIED APPLICATION RATE. REFER TO NATIVE SEED MIX TABLE
FOR SPECIES, PERCENTAGES AND APPLICATION RATES.
5. TREAT NATIVE SEED MIX AREA PRIOR TO INSTALLATION OF SEED
WITH APPROPRIATE HERBICIDE TO PROACTIVELY MITIGATE
HERBACEOUS WEED SPECIES GROWTH DURING ESTABLISHMENT
PERIOD THEN AFTER APPROPRIATE TIME PERIOD APPLY NATIVE SEED
AS CALLED FOR ON APPROVED PLANS.
6. AFTER SEEDING THE AREA SHALL BE COVERED WITH CRIMPED
STRAW OR OTHER APPROPRIATE METHODS AND PROVIDED
TEMPORARY IRRIGATION UNTIL SEED IS ESTABLISHED.
7. CONTRACTOR SHALL MONITOR SEEDED AREA FOR PROPER
IRRIGATION, EROSION CONTROL, GERMINATION AND RESEEDING AS
NEEDED TO ESTABLISH COVER.
8. THE APPROVED SEED MIX AREA IS INTENDED TO BE MAINTAINED IN
A NATURAL LIKE LANDSCAPE AESTHETIC. IF AND WHEN MOWING
OCCURS IN NATIVE GRASS SEED MIX AREAS DO NOT MOW LOWER
THAN 6 TO 8 INCHES IN HEIGHT TO AVOID INHIBITING NATIVE PLANT
GROWTH.
9. NATIVE SEED AREA WILL BE CONSIDERED ESTABLISHED WHEN
SEVENTY PERCENT TOTAL COVER IS REACHED WITH NO LARGER
THAN ONE FOOT SQUARE BARE SPOTS AND/OR UNTIL DEEMED
ESTABLISHED BY CITY PLANNING SERVICES AND NATURAL AREAS
STAFF.
Department: Forestry
Contact: Molly Roche, , mroche@fcgov.com
Topic: Landscape Plans
Comment Number: 4 Comment Originated: 12/19/2017
12/19/2017:
RESPONSE: Natural Areas is not concerned about suckering for the Narrowleaf Cottonwood; the Rocky Mountain Maple
was replaced with a Bigtooth Maple (which was already on the plant list); Natural Areas knows of sources
to find Netleaf Hackberry and would like to keep the native plant palette; Natural areas is not concerned
with the suckering of the Western Chokecherry and would like to keep the species for its high wildlife value.
Species Selection:
- Narrowleaf Cottonwood produces an abundance of sucker growth and can be
difficult to maintain as well as become a nuisance. Please consider whether this
species is appropriate where shown. Please consider the use of Lanceleaf and
Plains Cottonwood.
- Rocky Mountain Maple are typically sourced in the Pacific Northwest and are
not cold hardy. They are also not readily available in nurseries. City Forestry
suggests using Canyon Maple, ‘Rocky Mountain Glow’ Bigtooth Maple, or
several other ornamental species in place of all Rocky Mountain Maples
proposed on the plans.
- Netleaf Hackberry is not typically found in nursery stock. Please use Western
Hackberry on the landscape plans.
- Western Chokecherry produces an abundance of suck growth and can be
difficult to maintain as well as become a nuisance. Please use Sucker Punch
Chokecherry in place of the Western Chokecherry. This variety is readily
available at local nurseries.
Comment Number: 5 Comment Originated: 12/19/2017
12/19/2017:
RESPONSE: This note (#12) is already provided in the Tree Protection Notes (these notes have been shifted to sheet L.3).
Please add a note that says: Transplanting trees #2 and #3, shall follow the
recommendations of a qualified tree transplanting contractor in terms of size,
staking, mulching, and irrigation.
Comment Number: 6 Comment Originated: 12/19/2017
12/19/2017:
RESPONSE: A note has been added under the preservation / mitigation chart indicating the reason for removal and mitigation of
trees.
Please add a column to the Preservation/Mitigation of Existing trees table that
states the Reason for Removal.
Department: Light And Power
Contact: Austin Kreager, , akreager@fcgov.com
Topic: General
Comment Number: 1 Comment Originated: 12/26/2017
12/26/2017: COMMENT NOTED.
Currently there are two single phase transformers servicing this
site. One is a 50kVA and the other is a 100kVA. Both are 120/240V. Records
show that these are feeding a 400 amp panel. This will need to be field verified
to ensure nothing has changed. If a new service is required to serve the vehicle
storage area, we will need to discuss options of servicing the building. If
additional electrical demand is needed then system modification charges will
apply, as well as capacity fees.
Comment Number: 2 Comment Originated: 12/26/2017
12/26/2017: COMMENT NOTED.
If another transformer is needed in order to meet the electrical
plans then clearance requirements will need to be met. An 8' frontal and 3'
side/rear clearance will need to be met and cannot be located under the drip
line of any trees. Also transformers need to be within 10' of a drivable surface
for maintnance purposes. Please review our Electrical Service Standards to
ensure transformer and metering requirements are met. A link to this document
is below.
http://www.fcgov.com/utilities/business/builders-and-developers/development-fo
rms-guidelines-regulations
Comment Number: 3 Comment Originated: 12/26/2017
12/26/2017: COMMENT NOTED.
If additional electrical demand is needed then a Commercial
Service Form (C-1) and one-line diagram will need to be filled out and
submitted. A link to this C-1 form is below.
http://www.fcgov.com/utilities/business/builders-and-developers/development-fo
rms-guidelines-regulations
Comment Number: 4 Comment Originated: 12/26/2017
12/26/2017: Please contact Austin Kreager with Light & Power if you have any
questions. akreager@fcgov.com or 970-224-6152 THANK-YOU.
Department: PFA
Contact: Jim Lynxwiler, 970-416-2869, jlynxwiler@poudre-fire.org
Topic: General
Comment Number: 13 Comment Originated: 12/25/2017
12/25/2017: GATE ACCESS COMMENT NOTED.
Gate access for the east and west sides of the Maintenance Yard will require an
approved method of fire department access. All gate access systems (i.e. Knox
padlock or other) to be approved with Major Amendment approval. Fire
department signage may be required to help identify appropriate method of
gate access.
Comment Number: 14 Comment Originated: 12/25/2017
12/25/2017: ADDRESS POSTING/WAYFINDING COMMENT NOTED.
Building identifiers shall be prominently posted on each structure so as to be
visible from the road. Posting plan to be reviewed at building permit and verified
during field inspections. In such cases where building identifiers are not visible
from the road, signage may be required at intersections to assist with
wayfinding.
Comment Number: 15 Comment Originated: 12/25/2017
12/25/2017: FIRE LANE SIGNAGE COMMENT NOTED.
Fire lanes are typically posted with No Parking - Fire Lane signage. I have not
had an opportunity to clarify with the fire marshal is he wants typical signage
posted along portions of the Emergency Access Alignment on city property.
This item can be resolved during later rounds of MJA review or deferred to the
building permit stage.
RESPONSE: For consideration the fire lane is generally located between parking/garage staging areas. There may not be
much of an opportunity for signage placement. If fire lane delineation is necessary, it would likely have to occur with
pavement striping.
Department: Planning Services
Contact: Ryan Mounce, 970-224-6186, rmounce@fcgov.com
Topic: General
Comment Number: 9 Comment Originated: 12/20/2017
12/20/2017: COMMENTS NOTED & INFORMATION PROVIDED.
Planning is ready for hearing if the following information can be
clarified by the material submittal deadline (January 3rd) for Planning & Zoning
Board's January meeting:
- Provide the size of the modular building on the site plan and include this
square footage in the parking/bike parking calculations. Include photos of the
modular building one of the existing elevations sheets.
- Find an alternative location for the handicap space that will be impacted by the
modular building. This is needed to meet requirements for number of handicap
spaces.
- Rename the 'Interim Site Plan' sheets to Phase 1 Site Plan (see redlines).
Comment Number: 10 Comment Originated: 12/20/2017
12/20/2017: All remaining comments below can be addressed during Final
Plan review. COMMENT NOTED.
Comment Number: 11 Comment Originated: 12/20/2017
12/20/2017: Sheets L.3 and L.4 of the landscape plan show a modular building
and walkways west of the new line of visitor parking. I believe this is the prior
location and should be updated to reflect the site plan.
RESPONSE: The current site plan has been x-referenced in the landscape plan.
Comment Number: 12 Comment Originated: 12/20/2017
12/20/2017: In the parking calculations table on the site plan, please list the
number of handicap spaces. Five are currently shown and required, but one of
the spaces will need to be moved as it will be impacted by the modular building.
COMMENT NOTED & PROVIDED.
Comment Number: 13 Comment Originated: 12/20/2017
12/20/2017: More details will be needed on the trash/recycling enclosure.
Labels and details for the fueling pumps are not legible and size should be
increased. COMMENTS NOTED & PROVIDED.
Department: Stormwater Engineering
Contact: Wes Lamarque, 970-416-2418, wlamarque@fcgov.com
Topic: General
Comment Number: 4 Comment Originated: 01/13/2017
12/26/2017: Please show arrow at surface of pond.
RESPONSE: A drainage arrow has been added to the pond. RESPONSE: This note was previously added to sheet L.4, under
the heading “Rain Garden Note.” In addition, the detail on sheet L.2 states, “No weed barrier permitted on
bottom of pond.”
01/13/2017: Please add a note on the Landscape Plan that no weed barrier is
to be placed over the media section in the rain garden.
Comment Number: 5 Comment Originated: 01/13/2017
12/26/2017: Reminder Comment.
01/13/2017: Please provide documentation of the proposed drainage
alignment during final compliance.
RESPONSE: The alignment descriptions have been prepared and we are awaiting the dedication language from the
attorney. We will send for review once complete.
Department: Technical Services
Contact: Jeff County, 970-221-6588, jcounty@fcgov.com
Topic: Building Elevations
Comment Number: 19 Comment Originated: 12/21/2017
12/21/2017: There are sheet numbering issues. See redlines. REVISED.
Topic: Landscape Plans
Comment Number: 8 Comment Originated: 11/15/2016
12/21/2017: There are line over text issues. See redlines.
01/11/2017: There are line over text issues. See redlines.
11/15/2016: There are line over text issues. See redlines.
RESPONSE: All text has been selected and text mask has been applied to all text on the landscape plans.
Comment Number: 17 Comment Originated: 12/21/2017
12/21/2017: There is text that needs to be masked. Mask all text in hatched
areas. See redlines.
RESPONSE: All text has been selected and text mask has been applied to all text on the landscape plans.
Comment Number: 18 Comment Originated: 12/21/2017
12/21/2017: There are spelling issues. See redlines.
RESPONSE: “Landscape” has been corrected.
Topic: Lighting Plan
Comment Number: 10 Comment Originated: 11/15/2016
12/22/2017: This has not been corrected. REVISED.
01/11/2017: This has not been corrected.
11/15/2016: Please change the title to match the other plan sets. Nix Farm
Natural Areas Facility.
Topic: Site Plan
Comment Number: 16 Comment Originated: 12/21/2017
12/21/2017: There are line over text issues. See redlines. REVISED.
Department: Water-Wastewater Engineering
Contact: Wes Lamarque, 970-416-2418, wlamarque@fcgov.com
Topic: General
Comment Number: 3 Comment Originated: 12/26/2017
12/26/2017: Please specify new 2-inch wet tap.
RESPONSE: The plans show a new tap to the water main rather than previously constructed as coming off of the fire
hydrant service. The utility plan notation has been updated to direct a wet tap.
Comment Number: 4 Comment Originated: 12/26/2017
12/26/2017: Please show existing domestic service to be abandoned at the
main.
RESPONSE: The plans have been updated to direct the waterline abandonment at the waterline main.
1218 W. ASH, STE. A, WINDSOR, COLORADO 80550
TEL. 970.674.3300 – FAX 970.674.3303
January 29, 2018
Mr. Wes Lamarque
Fort Collins Utilities – Stormwater
700 Wood Street
Fort Collins, CO 80522
Re: Nix Farm Natural Areas Facility – Major Amendment 2016
Final Storm Drainage Letter
Dear Wes,
Please accept the following letter on behalf of the City of Fort Collins department of Natural Areas for the
proposed facility improvements demonstrating the site’s ability to comply with the City’s stormwater
requirements.
INTRODUCTION
The Nix Farm Natural Areas Facility – Major Amendment 2016 proposes to construct a new vehicle
storage building, expand the existing maintenance yard and provide a total of 14 additional
visitor/employee parking stalls at their existing Nix Farm Natural Area Campus. The site is located north
of the Burlington Northern Railroad Tracks, west of Timberline Road, south of the Cache La Poudre
River, and east of Lemay Avenue. The project is located in a portion of Section 18, Township 7 North,
Range 68 West of the Sixth Principal Meridian, in the City of Fort Collins, Larimer County, Colorado. A
vicinity map is attached for reference.
The site consists of approximately 27.48 acres, however the proposed improvements will disturb
approximately 1.5 acres. The proposed improvements will be completed in one phase of construction.
As part of the design efforts, a Master Plan study was conducted. For the purposes of this drainage study,
the Master Plan was referenced to review the potential impacts on the existing water quality pond.
EXISTING CONDITIONS
The project site is located within the Spring Creek Drainage Basin and detention is not required. An
existing water quality pond is located southeast of the maintenance yard. The design of the existing water
quality pond is described within the “Final Drainage and Erosion Control Report – Nix Farm Natural
Areas Facility”, prepared by JR Engineering, dated June 8, 2001. This report was updated with the
construction of the Natural Areas office building and is described within the “Final Drainage and Erosion
Control Report for Nix Farm Natural Areas Facility – Major Amendment”, prepared by Interwest
Consulting Group, dated May 13, 2013. In reference to the most recent 2013 drainage report, the site area
draining to the water quality pond is approximately 21% impervious (Basins 102, 103, and 105).
Portions of the project are not located within a FEMA mapped 100-yr floodplain though no improvements
are proposed within or that would affect the 100-yr floodplain.
Nix Farm Natural Areas Facility - Final Storm Drainage Letter
January 29, 2018
Page 2 of 4
PROPOSED DEVELOPMENT
The project will construct a 5,000 sqft vehicle storage building south of the existing maintenance building
and construct an expansion along the west side of the existing maintenance building. The maintenance
yard will be expanded to the east and south, and additional parking will be constructed along the north
and west drive isles.
The project is required to provide water quality capture volume and implement Low Impact Development
(LID) techniques for additional water quality enhancement. The previous basin boundaries were
referenced and adjusted for the proposed improvements. For the purposes of this report and the adjusted
basin boundaries, Basins 102, 103, 105, and 106 were reviewed. The proposed improvements occur
within Basins 102, 103, and 105. Basin 106 was reviewed due to the reduction in basin area and is mostly
unimproved native grassland.
Basin 102 consists of a portion of the existing office building, associated parking and walkways, and half
of the western access drive to the maintenance yard. This basin is unchanged with the proposed
improvements and is included in the analysis of the water quality pond. Basin 102 is approximately 0.41
acres and 47.1% impervious and runoff is conveyed to the water quality pond via an existing 18” culvert
and a proposed swale.
Basin 103 consists of north portion of the existing maintenance building, the northern portion of the
maintenance yard, and the access drive and parking to the north. The proposed improvements within this
basin consist of the expansion of the maintenance yard, improvement of the access drive, and additional
parking stalls south of the existing access drive. Basin 103 is approximately 1.13 acres and 67.2%
impervious. Runoff from Basin 103 is conveyed to the proposed rain garden than to the water quality
pond via a proposed culvert and swale.
Basin 105 consists of the south portion of the existing maintenance building, the proposed vehicle storage
building, the southern portion of the maintenance yard, half of the western access drive to the
maintenance yard, and the proposed parking stalls west of the access drive. Basin 105 is approximately
5.08 acres and 23.4% impervious. Runoff from Basin 105 is conveyed to the water quality pond via
overland sheet flow and swales.
The total area draining to and treated by the water quality pond is approximately 6.63 acres and is 32.3%
impervious. A total of 0.105 acre-ft of water quality capture volume is required. Analyzing the proposed
grading, this computes to a water surface elevation of 4927.32 feet. The top of the existing outlet
structure is 4928.40 feet which provides a total 0.331 acre-ft of water quality capture volume, exceeding
the required volume. The existing orifice plate will need to be replaced with a plate containing one
column and 3 rows of 7/8” orifice holes.
The attenuated peak 100-yr flow rate from the combined Basins 102, 103, and 105 is estimated to be
22.10 cfs. The existing pond spillway has capacity for this rate with 0.38 feet of freeboard.
All calculations and exhibits are attached for reference.
MASTER PLAN
As part of the Master Plan study we analyzed the proposed improvements to review the impacts to the
water quality pond. The Master Plan improvements would require 0.122 acre-ft of water quality volume.
It was determined that the existing pond, along with the current proposed grading adjustments, would
Nix Farm Natural Areas Facility - Final Storm Drainage Letter
January 29, 2018
Page 3 of 4
have capacity without significant grading adjustments. The orifice plate would need to be reconfigured
for the appropriate orifice sizes and the spillway would likely need to be adjusted.
LOW IMPACT DEVELOPMENT TECHNIQUES
In reference to the code requirements for implementation of Low Impact Development (LID) techniques,
the use of soft bottom swales and a rain garden are necessary to satisfy these requirements. The soft
bottom swales and rain garden promote infiltration while filtering runoff and capturing fine sediment that
drains off of the impervious areas. A Standard Operations Procedure will be provided at final design to
assist in ensuring that these BMPs will adequately perform over time.
Due to grading & elevation constraints, a 4” perforated pipe is utilized as the subsurface drain within the
rain garden.
Below is a description of the 4 step process for selecting structural BMPs:
Urban Drainage and Flood Control District (UDFCD) recommends a Four Step Process for receiving
water protection that focuses on reducing runoff volumes, treating the water quality capture volume
(WQCV), stabilizing drainageways and implementing long-term source controls. The Four Step Process
applies to the management of smaller, frequently occurring events.
Step 1: Employ Runoff Reduction Practices
To reduce runoff peaks, volumes, and pollutant loads from urbanizing areas, implement Low Impact
Development (LID) strategies, including Minimizing Directly Connected Impervious Areas (MDCIA).
Runoff throughout the site is mainly conveyed to the water quality pond via overland sheet flow and open
swales with soft bottom pans. Culverts are used route runoff under drives and walkways than day light to
swales. Allowing runoff to be in contact with site soils, whether overland sheet flow or within swales,
slows runoff and promotes infiltration, especially with the incorporation of soft bottom pans in the swales.
Step 2: Implement BMPs that Provide a Water Quality Capture Volume with Slow Release
Once runoff has been minimized as described in Step 1, the remaining runoff shall be treated through the
water quality pond designed for a 40-hour drain time.
Step 3: Stabilize Drainageways
Natural Drainage ways are subject to bed and bank erosion due to increases in frequency, duration, rate
and volume of runoff during and following development. Because the site will drain to an existing
storm system, bank stabilization is unnecessary with this project.
Step 4: Implement Site Specific and Other Source Control BMPs
Proactively controlling pollutants at their source by preventing pollution rather than removing
contaminants once they have entered the stormwater system or receiving waters is important when
protecting storm systems and receiving waters. This can be accomplished through site specific needs
such as construction site runoff control, post-construction runoff control and pollution prevention / good
housekeeping. It will be the responsibility of the contractor to develop a procedural best management
practice for the site.
Nix Farm Natural Areas Facility - Final Storm Drainage Letter
January 29, 2018
Page 4 of 4
All calculations are attached for reference.
EROSION CONTROL
Erosion and sedimentation will be controlled on-site by use of silt fences, culvert inlet protection, a gravel
construction entrance, and seeding and mulch. The measures are designed to limit the overall sediment
yield increase due to construction as required by the City of Fort Collins. During overlot and final
grading the soil will be roughened and furrowed perpendicular to the prevailing winds.
During the performance of the work required by these specifications or any operations appurtenant
thereto, whether on right-of-way provided by the City or elsewhere, the contractor shall furnish all labor,
equipment, materials, and means required. The Contractor shall carry out proper efficient measures
wherever and as necessary to reduce dust nuisance, and to prevent dust nuisance that has originated from
his operations from damaging crops, orchards, cultivated fields, and dwellings, or causing naissance to
persons. The Contractor will be held liable for any damage resulting from dust originating from his
operations under these specifications on right-of-way or elsewhere.
It is unlawful to track or cause to be tracked mud or other debris onto city streets or rights-of-way.
Wherever construction vehicles access routes or intersect paved public roads, previsions must be made to
minimize the transport of sediment by runoff or vehicles tracking onto the paved surface. Stabilized
construction entrances are required with base material consisting of 6” coarse aggregate. The contractor
will be responsible for clearing mud tracked onto city streets on a daily basis.
All temporary and permanent erosion and sediment control practices must be maintained and repaired as
needed to assure continued performance of their intended function. Silt fence will require periodic
replacement. Maintenance is the responsibility of the contractor.
All disturbed areas must be seeded and mulched within 30 days of project start. Vegetation shall not be
considered established until a ground cover is achieved which is demonstrated to be mature enough to
control soil erosion to the satisfaction of the City Inspector and to survive severe weather condition.
Thank you in advance for your time and if you have any questions or comments please contact me at
(970) 347-8917.
Sincerely,
Jason T. Claeys, P.E., LEED AP
Interwest Consulting Group
Attachments
PROJECT DATUM: NGVD29 UNADJUSTED
CITY OF FORT COLLINS BENCHMARK #51-01
WEST SIDE OF TIMBERLINE ROAD AT THE NORTH END OF A BRIDGE OVER THE POUDRE
RIVER ON TOP OF THE PARAPET WALL APPROXIMATELY 0.2 MILES SOUTH OF THE SOUTH
SIDE OF WEST MULBERRY STREET.
ELEV= 4923.75
CITY OF FORT COLLINS BENCHMARK #8-02
ON THE SOUTHEAST CORNER OF THE INTERSECTION OF LEMAY AVENUE AND
MULBERRY STREET, IN THE CURB, ON THE SOUTHEAST SIDE OF A TRIANGULAR ISLAND
THAT CONTAINS THE TRAFFIC SIGNAL.
ELEV= 4936.08
PLEASE NOTE: THIS PLAN SET IS USING NGVD29 UNADJUSTED FOR A VERTICAL DATUM.
IF NAVD88 DATUM IS REQUIRED FOR ANY PURPOSE,
THE FOLLOWING EQUATIONS SHOULD BE USED:
NAVD88 = 4923.75 (NGVD29 UNADJUSTED) + 3.18
NAVD88 = 4936.08 (NGVD29 UNADJUSTED) + 3.19
HORIZONTAL DATUM: COLORADO STATE PLAN COORDINATES NAD 83(2007) DATUM.
HORIZONTAL CONTROL BASED VRS.
SITE
Vicinity Map
Nix Farm Natural Area Facility
Major Amendment 2016
Hydrologic Soil Group—Larimer County Area, Colorado
(Nix Farm Natural Areas Facility - Major Amendment 2016)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
10/6/2016
Page 1 of 4
4491360 4491400 4491440 4491480 4491520 4491560 4491600
4491360 4491400 4491440 4491480 4491520 4491560 4491600
495900 495940 495980 496020 496060 496100 496140 496180 496220 496260 496300
495900 495940 495980 496020 496060 496100 496140 496180 496220 496260 496300
40° 34' 31'' N
105° 2' 54'' W
40° 34' 31'' N
105° 2' 36'' W
40° 34' 22'' N
105° 2' 54'' W
40° 34' 22'' N
105° 2' 36'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 25 50 100 150
Meters
Map Scale: 1:1,920 if printed on A landscape (11" x 8.5") sheet.
Warning: 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
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
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: http://websoilsurvey.nrcs.usda.gov
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
Hydrologic Soil Group
Hydrologic Soil Group— Summary by Map Unit — Larimer County Area, Colorado (CO644)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
54 Kim loam, 3 to 5 percent
slopes
B 0.5 6.5%
95 Satanta loam, 1 to 3
percent slopes
B 7.2 93.5%
103 Stoneham loam, 5 to 9
percent slopes
B 0.0 0.0%
Totals for Area of Interest 7.7 100.0%
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive precipitation
from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly
wet. These consist mainly of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well drained
soils that have moderately fine texture to moderately coarse texture. These soils
have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay layer
at or near the surface, and soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in their
natural condition are in group D are assigned to dual classes.
Hydrologic Soil Group—Larimer County Area, Colorado Nix Farm Natural Areas Facility -
Major Amendment 2016
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
10/6/2016
Page 3 of 4
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Hydrologic Soil Group—Larimer County Area, Colorado Nix Farm Natural Areas Facility -
Major Amendment 2016
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
10/6/2016
Page 4 of 4
Nix Farm Natural Areas Facility
DEVELOPED IMPERVIOUS AREA CALCULATION
Design Engineer:
Design Firm:
Project Number:
Date:
DESIGN CRITERIA:
Urban Storm Drainage Criteria Manual by Urban Drainage and Flood Control District, June 2001 (Revised January 2016)
BASINS:
%
Impervious
Runoff
Coefficient C
Return
Period
Frequency
Adjustment
Factor (Cf
)
100% 0.95
2-year to
10-year
1.00
90% 0.95 100-year 1.25
90% 0.95
40% 0.50
0% 0.25
C2
to C10
C100
102 17,968 0.412 6,092 1,601 1,036 0 9,238 47.1% 0.59 0.74
103 49,301 1.132 25,015 7,129 1,881 0 15,276 67.2% 0.73 0.92
105 221,426 5.083 37,058 16,346 0 0 168,023 23.4% 0.42 0.52
106 38,698 0.888 0 0 0 3,863 34,834 4.0% 0.27 0.34
To WQ Pond
(102+103+105)
288,695 6.628 68,165 25,076 2,917 0 192,537 32.3% 0.48 0.60
J.Claeys
Interwest Consulting Group
1276-095-00
December 22, 2016
% Impervious values from Table RO-3 in the Urban Storm Drainage Criteria Manual
Runoff Coefficients and Frequency Adjustment Factors for City of Fort Collins - Storm Water Criteria Manual
Land Use
Paved
Roof
Walks
Gravel/Pavers
Lawns
(Heavy, 2-7% Slope)
Sub-basin
Designation
Atotal
(sq feet)
Atotal
(acres)
Weighted %
Impervious
A COMPOSITE
paved
Nix Farm Natural Areas Facility
DEVELOPED TIME OF CONCENTRATION
Design Engineer:
Design Firm:
Project Number:
Date:
DESIGN CRITERIA:
EQUATIONS:
-Equation 6-2 -Equation 6-4 -Urbanized Check Equation 6-5
-Equation 6-3
CONSTRAINTS:
300 ft - Overland flow shall not exceed for developed condition
500 ft - Overland flow shall not exceed for undeveloped condition
Final t c = minimum of t i + t t and urbanized basin check
recommended minimum t c = 5 min for urbanized basins
BASINS
Type of Travel
Surface
Cv
2 102 47.1% 0.59 0.723 141 0.0100 11.10 155 0.0200 Paved Areas 20 2.83 0.91 12.01 0.0152 12.65 12.01
3 103 67.2% 0.73 0.438 59 0.0240 3.86 343 0.0143 Paved Areas 20 2.39 2.39 6.25 0.0157 9.82 6.25
5 105 23.4% 0.42 1.161 300 0.0042 28.88 657 0.0150 Tilage/Field 5 0.61 17.88 46.77 0.0116 22.90 22.90
5 Combined 32.3% 0.48 6.628 300 0.0042 26.16 657 0.0150 Tilage/Field 5 0.61 17.88 44.04 0.0116 20.64 20.64
SUB-BASIN DATA
%
Impervious
Urban Check
tc
(min)
OVERALL SLOPE
(ft/ft)
TRAVEL TIME (tt)
SLOPE
(ft/ft)
VELOCITY
(ft/s)
tt
(min)
AREA
(acres)
LENGTH
(ft)
REMARKS
Final
tc
(min)
tc
=ti
+tt
(min)
J.Claeys
Interwest Consulting Group
1276-095-00
December 22, 2016
SLOPE
(ft/ft)
Urban Storm Drainage Criteria Manual by Urban Drainage and Flood Control District, June 2001 (Revised January 2016)
ti
(min)
LENGTH Table RO-2
Nix Farm Natural Areas Facility
DEVELOPED PEAK RUNOFF
Design Engineer:
Design Firm:
Project Number:
Date:
DESIGN CRITERIA:
Town of Timnth - Design Criteria Manual (2016)
Urban Storm Drainage Criteria Manual by Urban Drainage and Flood Control District, June 2001 (Revised August 2006)
EQUATIONS: I = rainfall intensity (in/hr)
Q n = n -yr peak discharge (cfs) P 1 = one-hour point rainfall depth (in)
C n = n -yr runoff coefficient t c = time of concentration (min)
I n = n -yr rainfall intensity (in/hr) P 1-5yr = 1.14 in
A n = Basin drainage area (ac) P 1-10yr = 1.40 in
P 1-100yr = 2.86 in
BASIN SUMMARY:
Runoff Coeff.
(C5)
C(A)
(acres)
Intensity
(in/hr)
Q (ft3/s)
Runoff Coeff.
(C10)
C(A)
(acres)
Intensity
(in/hr)
Q (ft3/s)
Runoff Coeff.
(C100)
C(A)
(acres)
Intensity
(in/hr)
Q (ft3/s)
2 102 0.412 12.01 0.59 0.24 2.85 0.69 0.59 0.24 3.51 0.85 0.74 0.30 7.16 2.18
3 103 1.132 6.25 0.73 0.83 3.62 3.01 0.73 0.83 4.45 3.69 0.92 1.04 9.09 9.43
5 105 5.083 22.90 0.42 2.13 2.08 4.43 0.42 2.13 2.56 5.44 0.52 2.66 5.22 13.89
5 Combined 6.628 20.64 0.48 3.20 2.20 7.05 0.48 3.20 2.70 8.65 0.60 4.00 5.52 22.10
Design
Point
Sub-basin Area (acres) tc (min)
5-yr Peak Runoff 100-yr Peak Runoff
J.Claeys
Interwest Consulting Group
1276-095-00
December 22, 2016
10-yr Peak Runoff
Q n = C n I n A n
0.786651)
1
( 10 )
28 . 5
t c
P
I
+
=
Nix Farm Natural Areas Facility
Water Quality Pond and Outlet Sizing
Design Engineer:
Design Firm:
Project Number:
Date:
DESIGN CRITERIA:
REQUIRED WATER QUALITY CAPTURE VOLUME (WQCV):
Tributary Area, A 6.628 acres
Composite. Imperviousness, I 32.3%
WQCV (watershed inches) 0.158 inches 40-Hour Drain Time (Fig SQ-2)
Required WQCV 0.105 acre-feet Including 20% for Sedimentation
WATER QUALITY OUTLET SIZING (Per USDCM, Volume 3):
Design Water Quality Depth, DWQ
1.15 ft
Determine K40
K40
= 0.013DWQ
2
+ 0.22DWQ
- 0.10 0.171
Maximum Area per Row, a a = WQCV / K40
0.615 square inches
Number of Rows, nr 3 rows
Number of Columns, nc (See Table 6a-1 for Max.) 1 columns
Choose Hole Diameter 7/8 inches
Use USDCM Volume 3, Figure 5 0.875 inches
Total Area per Row, Ao
0.60 square inches
Total Outlet Area, Aot
1.80 square inches
Does design work? Yes
Minimum Steel Plate Thickness 1/4 inch
(Not Used)
Number of Rows, nr 2 rows
Choose Rectangular Hole Width (w/ 2" Height) 0 inches
Use USDCM Volume 3, Figure 5 0.000 inches
Total Outlet Area, Aot
0.00 square inches
Does design work? Yes
Minimum Steel Plate Thickness 1/4 inch
Urban Storm Drainage Criteria Manual (USDCM) Volume III, Urban Drainage and Flood Control District, June 2001 (Updated November 2010)
Circular Perforation Sizing
Rectangular Perforation Sizing
J.Claeys
Interwest Consulting Group
1276-095-00
December 22, 2016
* * 1 . 2
12
Area
WQCV
Volume
=
1276-095-00 PondCalcs.xls - WQCV & Outlet Structure Page 1 of 4 Interwest Consulting Group
Nix Farm Natural Areas Facility
Water Quality Pond and Outlet Sizing
Design Engineer:
Design Firm:
Project Number:
Date:
J.Claeys
Interwest Consulting Group
1276-095-00
December 22, 2016
WATER QUALITY TRASH RACK SIZING (Per USDCM, Volume 3)
Required Open Area, At
At
=0.5*[77(e
-0.124D
)]*Aot
62 square inches
Min. Distance between Columns, Sc
3 inches
Width of Trash Rack and Concrete Opening per Column 3 inches
Use USDCM Volume 3, Table 6a-1
Total Width, Wconc
3 inches
Height of Trash Rack Screen, Htr
13 13/16 inches Check - Does Not Work
Type of Screen S.S. #93 VEE Wire (US Filter)
Screen Opening Slot Dimension 0.139" (US Filter)
Support Rod Type (See Table 6a-2)
Spacing of Support Rod (O.C.) 3/4 inches O.C.
Total Screen Thickness (See Table 6a-2) 0.31 inches
Carbon Steel Frame Type (See Table 6a-2)
(Not Used)
Required Open Area, At
(including 50% clogging)
At
=0.5*[77(e
-0.124D
)]*Aot
0 square inches
Width of Trash Rack Opening, Wopening
1 inches
Use USDCM Volume 3, Table 6b-1
Width of Concrete Opening, Wconc
12 inches
Min Height of Trash Rack Screen, Htr
(including 2' 4" below lowest openings) 28.00 inches
Type of Screen Kelmp KRP Series Aluminum Bar Gate (or Equal)
Screen Opening Slot Dimension 3/16" Bars on 1-3/16" Centers
Minimum Bearing Bar Size (See Table 6b-2)
Rectangular Perforation Trash Rack Sizing
1 in x 3/16 in
#156 VEE
3/8in x 1.0in flat bar
Circular Perforation Trash Rack Sizing
1276-095-00 PondCalcs.xls - WQCV & Outlet Structure Page 2 of 4 Interwest Consulting Group
Nix Farm Natural Areas Facility
Critical Pond Elevations
Design Engineer:
Design Firm:
Project Number:
Date:
DESIGN CRITERIA
Urban Storm Drainage Criteria Manual, Urban Drainage and Flood Control District, June 2001 (Revised January 2016)
Stage Storage
Volume (pond volume calculated using the prismoidal formula):
CONTOUR (FT) AREA (FT2) AREA (ACRE)
VOLUME
(ACRE-FT)
DEPTH (FT)
CUMULATIVE VOLUME
(ACRE-FT)
4925.65 0 0.000 0.000 0.00 0.000
4926.0 421 0.010 0.001 0.35 0.001 - Orifice Invert = 4926.17
4927.0 4374 0.100 0.047 1.35 0.048
4928.0 10414 0.239 0.176 2.35 0.224
4928.4 12837 0.295 0.107 2.75 0.331 -Top of Existing Outlet Structure
4929.0 16904 0.388 0.204 3.35 0.535 - Spillway
0.105 4927.32 ft
J.Claeys
Interwest Consulting Group
1276-095-00
December 22, 2016
Required Water Quality Capture Volume (WQCV) =
Acre-Ft Interpolates to an Elev. of
( )
3
AAAADepth 1 2 1 2
V
+ +
=
1276-095-00 PondCalcs.xls - Pond Stage Storage Page 3 of 4 Interwest Consulting Group
Nix Farm Natural Areas Facility
Emergency Overflow Spillway Calculations
Design Engineer:
Design Firm:
Project Number:
Date:
Broad-Crested Weir Equation-Trapezoidal Shape
where: Q = Discharge (cfs)
C = Weir Coeffecient
L = Weir Length (ft)
H = Average Weir Head (ft)
H:V =Side Slope
Calculations
Knowns: 4.00
0.62 ft
2.6
4929.00 ft
22.1 cfs
14.91 ft
15 ft
0.38 ft
1.00 ft
Topft of Berm Elevation 4930.00
100-yr Pond Inflow
Calculated Spillway
Use Spillway Length
Total Spillway Depth
Spillway Freeboard
Side Slopes (H:V)
Desired Spillway Head
Weir Coefficient
Spillway Elevation
J.Claeys
Interwest Consulting Group
1276-095-00
December 22, 2016
2
5
2
3
H
V
H
QCLH C
= +
1276-095-00 PondCalcs.xls - Spillway Page 4 of 4 Interwest Consulting Group
Nix Farm Natural Areas Facility
MASTER PLANNED IMPERVIOUS AREA CALCULATION
Design Engineer:
Design Firm:
Project Number:
Date:
DESIGN CRITERIA:
Urban Storm Drainage Criteria Manual by Urban Drainage and Flood Control District, June 2001 (Revised January 2016)
BASINS:
%
Impervious
Runoff
Coefficient C
Return
Period
Frequency
Adjustment
Factor (Cf
)
100% 0.95
2-year to
10-year
1.00
90% 0.95 100-year 1.25
90% 0.95
40% 0.50
0% 0.25
C2
to C10
C100
102 17,968 0.412 5,006 2,350 1,293 0 9,318 46.1% 0.59 0.73
103 49,301 1.132 25,015 7,129 1,881 0 15,276 67.2% 0.73 0.92
105 221,426 5.083 55,071 21,343 4,846 0 140,167 35.5% 0.51 0.63
106 38,698 0.888 0 0 0 3,863 34,834 4.0% 0.27 0.34
To WQ Pond
(102+103+105)
288,695 6.628 85,092 30,823 8,020 0 164,760 41.6% 0.55 0.69
J.Claeys
Interwest Consulting Group
1276-095-00
December 22, 2016
% Impervious values from Table RO-3 in the Urban Storm Drainage Criteria Manual
Runoff Coefficients and Frequency Adjustment Factors for City of Fort Collins - Storm Water Criteria Manual
Paved
Roof
Walks
Land Use
Gravel/Pavers
Lawns
(Heavy, 2-7% Slope)
Agravel/pavers
(sq feet)
Alawn
(sq feet)
Weighted %
Impervious
Sub-basin COMPOSITE
Designation
Atotal
(sq feet)
Nix Farm Natural Areas Facility
Water Quality Pond and Outlet Sizing - Master Plan
Design Engineer:
Design Firm:
Project Number:
Date:
DESIGN CRITERIA:
REQUIRED WATER QUALITY CAPTURE VOLUME (WQCV):
Tributary Area, A 6.628 acres
Composite. Imperviousness, I 41.6%
WQCV (watershed inches) 0.184 inches 40-Hour Drain Time (Fig SQ-2)
Required WQCV 0.122 acre-feet Including 20% for Sedimentation
4371.6558
WATER 10251.QUALITY 604 OUTLET SIZING (Per USDCM, Volume 3):
12783.707
16545.6252 1.25 ft
Determine K40
K40
= 0.013DWQ
2
+ 0.22DWQ
- 0.10 0.195
Maximum Area per Row, a a = WQCV / K40
0.626 square inches
Number of Rows, nr 3 rows
Number of Columns, nc (See Table 6a-1 for Max.) 1 columns
Choose Hole Diameter 7/8 inches
Use USDCM Volume 3, Figure 5 0.875 inches
Total Area per Row, Ao
0.60 square inches
Total Outlet Area, Aot
1.80 square inches
Does design work? Yes
Minimum Steel Plate Thickness 1/4 inch
(Not Used)
Number of Rows, nr 2 rows
Choose Rectangular Hole Width (w/ 2" Height) 0 inches
Use USDCM Volume 3, Figure 5 0.000 inches
Total Outlet Area, Aot
0.00 square inches
Does design work? Yes
Minimum Steel Plate Thickness 1/4 inch
J.Claeys
Interwest Consulting Group
1276-095-00
December 22, 2016
Urban Storm Drainage Criteria Manual (USDCM) Volume III, Urban Drainage and Flood Control District, June 2001 (Updated November 2010)
Circular Perforation Sizing
Rectangular Perforation Sizing
* * 1 . 2
12
Area
WQCV
Volume
=
Nix Farm Natural Areas Facility
Water Quality Pond and Outlet Sizing - Master Plan
Design Engineer:
Design Firm:
Project Number:
Date:
J.Claeys
Interwest Consulting Group
1276-095-00
December 22, 2016
WATER QUALITY TRASH RACK SIZING (Per USDCM, Volume 3)
Required Open Area, At
At
=0.5*[77(e
-0.124D
)]*Aot
62 square inches
Min. Distance between Columns, Sc
3 inches
Width of Trash Rack and Concrete Opening per Column 3 inches
Use USDCM Volume 3, Table 6a-1
Total Width, Wconc
3 inches
Height of Trash Rack Screen, Htr
15 inches Check - Does Not Work
Type of Screen S.S. #93 VEE Wire (US Filter)
Screen Opening Slot Dimension 0.139" (US Filter)
Support Rod Type (See Table 6a-2)
Spacing of Support Rod (O.C.) 3/4 inches O.C.
Total Screen Thickness (See Table 6a-2) 0.31 inches
Carbon Steel Frame Type (See Table 6a-2)
(Not Used)
Required Open Area, At
(including 50% clogging)
At
=0.5*[77(e
-0.124D
)]*Aot
0 square inches
Width of Trash Rack Opening, Wopening
1 inches
Use USDCM Volume 3, Table 6b-1
Width of Concrete Opening, Wconc
12 inches
Min Height of Trash Rack Screen, Htr
(including 2' 4" below lowest openings) 28.00 inches
Type of Screen Kelmp KRP Series Aluminum Bar Gate (or Equal)
Screen Opening Slot Dimension 3/16" Bars on 1-3/16" Centers
Minimum Bearing Bar Size (See Table 6b-2)
3/8in x 1.0in flat bar
Circular Perforation Trash Rack Sizing
Rectangular Perforation Trash Rack Sizing
1 in x 3/16 in
#156 VEE
1276-095-00 PondCalcs - Masterplan.xls - WQCV & Outlet StructurePage 2 of 3 Interwest Consulting Group
Nix Farm Natural Areas Facility
Critical Pond Elevations - Master Plan
Design Engineer:
Design Firm:
Project Number:
Date:
DESIGN CRITERIA
Urban Storm Drainage Criteria Manual, Urban Drainage and Flood Control District, June 2001 (Revised January 2016)
Stage Storage
Volume (pond volume calculated using the prismoidal formula):
CONTOUR (FT) AREA (FT2) AREA (ACRE)
VOLUME
(ACRE-FT)
DEPTH (FT)
CUMULATIVE VOLUME
(ACRE-FT)
4925.65 0 0.000 0.000 0.00 0.000
4926.0 421 0.010 0.001 0.35 0.001 - Orifice Invert = 4926.17
4927.0 4374 0.100 0.047 1.35 0.048
4928.0 10414 0.239 0.176 2.35 0.224
4928.4 12837 0.295 0.107 2.75 0.331 -Top of Existing Outlet Structure
4929.0 16904 0.388 0.204 3.35 0.535 - Spillway
0.122 4927.42 ft
J.Claeys
Interwest Consulting Group
1276-095-00
December 22, 2016
Required Water Quality Capture Volume (WQCV) =
Acre-Ft Interpolates to an Elev. of
( )
3
AAAADepth 1 2 1 2
V
+ +
=
1276-095-00 PondCalcs - Masterplan.xls - Pond Stage Storage Page 3 of 3 Interwest Consulting Group
Nix Farm Natural Areas Facility
Low Impact Development
Design Engineer:
Design Firm:
Project Number:
Date:
DESIGN CRITERIA
Low Impact Development Summary
Pavement Area Summary
33,331 sqft
0 sqft
0.0%
Developed Area Summary
38,331 sqft
Total Area required for Treatment (75%): 28,748 sqft
0 sqft
0 sqft
0 sqft
34,026 sqft
34,026 sqft
88.8%
Impervious Area Treated by Rain Garden (Basin 103):
Proposed Area of Pavers:
Additional Area Treated by Pavers:
Total Area Treated by Pavers:
Total Area Treated by LID:
Percent Site Area Treated by LID:
Total New Paved Area:
Permeable Paver Area:
Percent Pavement Area as Permeable Pavers:
Total New Impervious Area:
J.Claeys
Interwest Consulting Group
1276-095-00
March 2, 2017
Urban Storm Drainage Criteria Manual, Urban Drainage and Flood Control District, January 2010
City of Fort Collins - Ordinance No. 007, 2016
- Treat at least 75% of any newly developed or redeveloped area using one or a combination of LID
techniques, or
- Treat at least 50% of any newly developed or redeveloped area using one or a combination of LID
techniques when 25% of private driveable surfaces are permeable.
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia = 67.2 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 0.672
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.21 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 49,301 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 = 0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region, VWQCV OTHER = 864.2 cu ft
Water Quality Capture Volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER = cu ft
(Only if a different WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth (12-inch maximum) DWQCV = 12 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin = 663 sq ft
D) Actual Flat Surface Area AActual = 769 sq ft
E) Area at Design Depth (Top Surface Area) ATop = 1292 sq ft
F) Rain Garden Total Volume VT= 1,030 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
CoFC Rain Garden Section (12" Growing Media, 6" Pea Gravel,
10" CDOT Class 2)
4. Underdrain System
A) Are underdrains provided?
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y = 1.9 ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 = 864 cu ft
iii) Orifice Diameter, 3/8" Minimum DO = 2/3 in
Design Procedure Form: Rain Garden (RG)
J.Claeys
Interwest Consulting Group
December 21, 2016
Nix Farm Natural Areas Facility
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
1276-095-00 UD-BMP_v3.05.xlsm, RG 12/21/2016, 9:41 AM
Sheet 2 of 2
Designer:
Company:
Date:
Project:
Location:
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric
A) Is an impermeable liner provided due to proximity
of structures or groundwater contamination?
6. Inlet / Outlet Control
A) Inlet Control
7. Vegetation
8. Irrigation
A) Will the rain garden be irrigated?
Notes:
Design Procedure Form: Rain Garden (RG)
J.Claeys
Interwest Consulting Group
December 21, 2016
Nix Farm Natural Areas Facility
Choose One
Choose One
Choose One
Sheet Flow- No Energy Dissipation Required
Concentrated Flow- Energy Dissipation Provided
Plantings
Seed (Plan for frequent weed control)
Sand Grown or Other High Infiltration Sod
Choose One
YES
NO
YES
NO
1276-095-00 UD-BMP_v3.05.xlsm, RG 12/21/2016, 9:41 AM
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Wednesday, Dec 21 2016
East Swale
Triangular
Side Slopes (z:1) = 4.00, 4.00
Total Depth (ft) = 2.75
Invert Elev (ft) = 4928.13
Slope (%) = 0.50
N-Value = 0.015
Calculations
Compute by: Known Q
Known Q (cfs) = 9.43
Highlighted
Depth (ft) = 0.80
Q (cfs) = 9.430
Area (sqft) = 2.56
Velocity (ft/s) = 3.68
Wetted Perim (ft) = 6.60
Crit Depth, Yc (ft) = 0.81
Top Width (ft) = 6.40
EGL (ft) = 1.01
0 5 10 15 20 25 30 35
Elev (ft) Depth (ft)
Section
4927.50 -0.63
4928.00 -0.13
4928.50 0.37
4929.00 0.87
4929.50 1.37
4930.00 1.87
4930.50 2.37
4931.00 2.87
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Wednesday, Dec 21 2016
West Swale
Triangular
Side Slopes (z:1) = 4.00, 4.00
Total Depth (ft) = 2.75
Invert Elev (ft) = 4930.75
Slope (%) = 1.10
N-Value = 0.015
Calculations
Compute by: Known Q
Known Q (cfs) = 13.89
Highlighted
Depth (ft) = 0.80
Q (cfs) = 13.89
Area (sqft) = 2.56
Velocity (ft/s) = 5.43
Wetted Perim (ft) = 6.60
Crit Depth, Yc (ft) = 0.95
Top Width (ft) = 6.40
EGL (ft) = 1.26
0 5 10 15 20 25 30 35
Elev (ft) Depth (ft)
Section
4929.00 -1.75
4930.00 -0.75
4931.00 0.25
4932.00 1.25
4933.00 2.25
4934.00 3.25
Reach (ft)
Weir Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Wednesday, Dec 21 2016
<Name>
Rectangular Weir
Crest = Broad
Bottom Length (ft) = 12.00
Total Depth (ft) = 0.50
Calculations
Weir Coeff. Cw = 2.60
Compute by: Known Q
Known Q (cfs) = 9.43
Highlighted
Depth (ft) = 0.45
Q (cfs) = 9.430
Area (sqft) = 5.40
Velocity (ft/s) = 1.75
Top Width (ft) = 12.00
0 2 4 6 8 10 12 14 16
Depth (ft) <Name> Depth (ft)
-0.50 -0.50
0.00 0.00
0.50 0.50
1.00 1.00
Length (ft)
Weir W.S.
EROSION CONTROL REPORT/STORMWATER MANAGEMENT PLAN
FOR
Nix Farm – Major Amendment 2016
Prepared by:
Interwest Consulting Group
1218 West Ash, Suite A
Windsor, Colorado 80550
Phone: 970.674.3300
Fax: 970.674.3303
Prepared for:
City of Fort Collins
Natural Areas Department
1745 Hoffman Mill Road
Fort Collins, Colorado 80524
Phone: 970.416.2815
January 29, 2018
January 29, 2018
Mr. Jesse Schlam
City of Fort Collins Stormwater
700 Wood Street
Fort Collins, CO 80522-0580
RE: Erosion Control Report /Stormwater Management Plan for Nix Farm – Major
Amendment 2016
Dear Jesse,
I am pleased to submit for your review and approval, this Erosion Control Report/Stormwater
Management Plan associated with the proposed Nix Farm – Major Amendment 2016
improvements. This report provides the City with an erosion control plan for the proposed
development that addresses the topics outlined in the City Erosion Control Report Requirements.
This plan mimics the State of Colorado General Permit and Stormwater Management Plan
requirements.
I appreciate your time and consideration in reviewing this submittal. Please call if you have any
questions.
Sincerely,
Jason T. Claeys, P.E., LEED AP
Interwest Consulting Group
TABLE OF CONTENTS
1. INTRODUCTION .................................................................................................................... 1
2. SITE DESCRIPTION ............................................................................................................... 1
2.1. Erosion and Sediment Controls ........................................................................................ 4
3.2 Materials Handling and Spill Prevention ......................................................................... 6
3. STORMWATER MANAGEMENT CONTROLS .................................................................. 8
3.1. SWMP Administrator ....................................................................................................... 8
3.2. Identification of Potential Pollution Sources ................................................................... 8
4. FINAL STABILIZATION AND LONG TERM STORMWATER MANAGEMENT ......... 10
5. INSPECTION AND MAINTENANCE ................................................................................. 10
5.1. City of Fort Collins Standard Erosion and Sediment Control Notes ............................. 11
5.2. City of Fort Collins Erosion Control Security Calculations ........................................... 12
6. SWMP IMPLEMENTATION................................................................................................ 14
APPENDIX A—BMP DETAILS ................................................................................................ A
APPENDIX B—EROSION CONTROL PLAN AND SITE MAP ........................................... B
APPENDIX C—CONSTRUCTION SEQUENCE .................................................................... C
APPENDIX D—SOIL INFORMATION ................................................................................... D
LIST OF FIGURES
Figure 1—Vicinity Map…………………………………………………………………………..2
LIST OF TABLES
Table 2.1—On-site Soil Characteristics…………………………………………………………..2
Table 2.2—Sub-Basin Characteristics…………………...………………………………………..3
Table 6.1—Erosion Control Cost Estimate……………………………………………………...13
1
1. INTRODUCTION
The primary purpose of preparing and maintaining a stormwater management plan is to
improve the health and quality of the State's urban waterways. The preparation and
maintenance of the plan will contribute to this objective by facilitating an approach to
stormwater management, establishing a program of actions to be used during construction
activities, and describing stormwater management controls and various Best Management
Practices (BMPs) necessary to reduce erosion, sediment and pollutants in stormwater
discharge.
Information concerning the State of Colorado General Permit and Stormwater
Management Plan are not included in the appendices of this report. The site is over one
acre and will require a SWMP permit.
2. SITE DESCRIPTION
The Nix Farm Natural Areas Facility – Major Amendment 2016 proposes to construct a
new vehicle storage building, expand the existing maintenance yard and provide a total of
14 additional visitor/employee parking stalls at their existing Nix Farm Natural Area
Campus. The site is located north of the Burlington Northern Railroad Tracks, west of
Timberline Road, south of the Cache La Poudre River, and east of Lemay Avenue. The
project is located in a portion of Section 18, Township 7 North, Range 68 West of the
Sixth Principal Meridian, in the City of Fort Collins, Larimer County, Colorado. A
vicinity map is included for reference.
The site consists of approximately 27.48 acres, however the proposed improvements will
disturb approximately 1.5 acres. The proposed improvements will be completed in one
phase of construction. The existing site currently consists of multiple office and
maintenance buildings with supporting access drives, parking, and storage. It is estimated
that 4.0± acres has been previously developed with the remaining 23.48 acres being
sparsely vegetated open space with native plans and grasses. The existing site currently
has a vegetative cover of approximately 80%.
The project will construct a 5,000 sqft vehicle storage building south of the existing
maintenance building and construct an expansion along the west side of the existing
maintenance building. The maintenance yard will be expanded to the east and south, and
2
additional parking will be constructed along the north and west drive isles.
Figure 1--Vicinity Map
Existing soil types on site as classified by the NRCS Soil Survey of Larimer County are
classified as Kim Loam, Satanta Loam, and Stoneham Loam. Please refer to Table 2.1
for additional soil characteristics.
Table 2.1: On-site Soil Characteristics
Soil Type
Percent of
Site
Hydrologic
Soil Group1
K
Factor2
Wind
Group3
Kim Loam 7.5% B 0.28 4L
Satanta Loam 92.4% B 0.32 5
Stoneham Loam 0% B 0.28 6
1Hydrologic soil groups range from A to D with group A having a high infiltration rate and D having a very
slow infiltration rate
3
2K factors range from 0.02 to 0.69. The higher value, the more susceptible the soil is to sheet and rill
erosion by water.
3Soils assigned to wind group 1 are the most susceptible to wind erosion, soils assigned to wind group 8 are
the least susceptible.
Overall, the soils on site can be classified as moderately erodible and thus the project
must implement an adequate erosion control strategy to control sediment migration from
leaving the site. Please refer to Appendix D for the detailed on-site soil information from
the NRCS Soil Survey of Larimer County.
All of the proposed development runoff will be collected and conveyed to the existing
water quality pond located southeast of the proposed improvements where it will be
allowed to settle before being released into the existing retention ponds further east of the
site.
The anticipated sequence of construction shall progress as follows:
1) Installation of perimeter and offsite erosion control measures (mainly outlet
protection at the water quality pond outlet structure). Other measures as required
for erosion control will be constructed throughout the project.
2) Clearing, stripping and grading
3) Utility installation
4) Sub-grade preparation for the parking areas and maintenance yard pavements
5) Paving
6) Building construction (this may occur simultaneously with items 5 through 7)
7) Final grading and landscaping. All disturbed ground will be impervious (concrete,
asphalt, or building), seeded and mulched, sodded or xeriscaped to permanently
stabilize the site. The rain garden will be completed at this time as well.
The run-off coefficients associated with this project for onsite Sub-Basins are as follows:
Table 2.2: Sub-Basin Characteristics
Sub-Basin Area (AC) C2 to C10 C100
102 0.41 0.59 0.74
103 1.13 0.73 0.92
105 1.08 0.42 0.52
4
106 0.89 0.27 0.34
No outside sources of pollution currently exist on this site. Potential pollutant sources
brought onto the site during construction will be discussed (along with spill prevention)
in Section 3.2 below. The anticipated non-stormwater components of discharge with this
project are landscape irrigation return flows. Runoff from the site will flow toward the
detention pond and then be conveyed through a storm pipe network to the existing storm
drain within Redwood Street.
BMPS FOR STORMWATER POLLUTION PREVENTION
2.1. Erosion and Sediment Controls
Structural Practices: Structural practices for the site will consist mainly of vehicle
tracking pad, concrete washout area, outlet structure protection and sediment control logs
which are described in detail in the following paragraphs. Detail drawings of these BMPs
are also included in Appendix A. These BMPs are expected to change as the construction
progresses and it is the responsibility of the contractor to ensure appropriate BMPs are in
place and/or removed at the appropriate time in the construction sequence. All temporary
and permanent erosion and sediment control practices must be maintained and repaired as
needed to assure continued performance of their intended function. All BMPs shall be
inspected and repaired or replaced as indicated in Section 6 and as required to satisfy the
conditions of the Permit.
Vehicle tracking pad is intended to trap mud and sediment within coarse grain material
and provide clean access to public roadways. Wherever construction vehicle access routes
intersect paved public roads a vehicle tracking control pad shall be installed to minimize
the transport of sediment (mud) by runoff or vehicles tracking onto the paved surface.
Pads shall be maintained and refurbished when necessary to obtain their intended result.
Concrete washout area is intended to contain washout liquids and solids that result from
the cleaning of concrete trucks and pumps. Washouts should be placed near the area
where the concrete is being poured.
Sediment control logs, inlet protection, and outlet structure protection prevent sediment
from entering storm drainage systems prior to permanent stabilization of the disturbed
site area via ponding and settling of sediment. Sediment control logs or gravel bags shall
5
be placed at the upstream end and downstream end of new culverts and inlets as well as
existing culverts and inlets near the site as inlet protection. Storm sewer culvert
protection must be inspected and maintained after every rainfall event that produces
runoff. Sediment must be removed and rocks replaced. Gravel bag wattles shall be used
as flow line protection along proposed curb & gutter on the site. Sediment control logs
shall also be implemented as sediment control and velocity reduction in existing and
proposed swales as necessary. Sediment control logs shall be installed immediately upon
completion of over-lot grading and/or the installation of the proposed swales.
Non-Structural Practices: All low sloped areas exposed during land disturbing activity
(stripping, grading, utility installations, stockpiling, filling, etc.) shall be kept in a
roughened condition by ripping or disking along land contours until mulch, vegetation or
other permanent erosion control is installed.
All exposed steep sloped areas exposed during land disturbing activity (stripping,
grading, utility installations, stockpiling, filling, etc.) shall have slope protection. The
contractor shall use a "tracked" vehicle, run perpendicular to slope so that the tracking
runs on the contour to inhibit rill/gully erosion; the contractor may use other windrow-
type methods as necessary.
No soil shall remain exposed by land disturbing activity for more than thirty (30) days.
At that time temporary or permanent erosion control seed/mulch, landscaping, etc. is
required.
Additional Non-Structural Practices are strongly encouraged such as minimizing the
disturbance of soils and vegetation, providing educational materials on disposal
/recycling, spill prevention / clean up, identification and elimination of illicit discharges,
promotion of street sweeping and the development of public education programs.
THE CONTRACTOR SHALL ADD ANY AND ALL BMP’S AND DETAILS
NEEDED FOR SEDIMENT/EROSION CONTROL.
6
3.2 Materials Handling and Spill Prevention
Potential impacts from significant materials and their handling are as follows:
Chemicals, cleaning substances, and petroleum products related to the construction will
be stored within the construction trailer or storage shed where it will not be in contact
with precipitation. No storage of these materials will be allowed outside.
Fueling and maintenance of equipment shall take place at the construction staging area.
Fueling will be accomplished with fueling trucks on an as needed basis. Absorbent (kitty
litter) will be in the construction trailer and applied on any spill immediately and the dry
material disposed of properly and legally.
All construction waste shall be disposed of in the available dumpsters throughout the
workday. Liquid wastes will be hauled off site and disposed of properly and legally.
Any cleaning or maintenance of small equipment will be required to be done within a
containment device (horse trough or small “kiddy pool”) and the liquid disposed of
properly and legally.
In the event of any spill, the SWMP Administrator shall be immediately notified.
Spills can be broken into three categories. Their definitions and the procedures required
to address the spills are as follow:
Minor Spill – A spill generally of less than 5 gallons which is unlikely to reach adjacent
waters (i.e. equipment leak).
Procedure:
a. Stop the source of the spill.
b. Contain the spillage.
c. Contact the SWMP Administrator.
d. Clean up the spill with on-site absorbent material (kitty litter)
e. Dispose of the dry material properly or legally.
f. Document the spill and the response in the SWMP including dates
and times – verify that the pollutants are completely cleaned up.
g. Include incident in the following training meeting.
h. Provide information to the City of Fort Collins at the next regular
inspection.
7
Significant Spill – A spill of pollutants or oils of any size that will likely or has reached
adjacent waters, may endanger health or the environment, or which may exceed a water
quality standard.
Procedure:
a. Stop the source of the spill.
b. Contain the spillage.
c. Contact the SWMP Administrator.
d. Clean up the spill with on-site absorbent material (kitty litter)
e. Dispose of the dry material properly or legally.
f. Document the spill and the response in the SWMP – verify that the
pollutants are completely cleaned up.
g. Notify the City of Fort Collins (970) 221-6700 and the Colorado
Department of Public Health and Environment spill reporting line
(877) 518-5608 of the spill.
h. Notify the same two entities above with a written submission
(outlined within the permit) within 5 calendar days.
i. Include incident in the following training meeting.
Hazardous Spill – A spill of a dangerous substance requiring expert cleanup.
Procedure:
a. Secure the area – do not approach the spill.
b. Offer first aid to any injured parties.
c. Call 911 and describe the nature of the spill and any injuries.
d. If possible, isolate downstream areas from the spill (for example,
cover an inlet that is downstream and a safe distance from the spill
with plastic and soil).
e. Contact the SWMP Administrator.
f. Document the spill and the response in the SWMP
g. Notify the City of Fort Collins (970) 221-6700 and the Colorado
Department of Public Health and Environment spill reporting line
(877) 518-5608 of the spill.
h. Notify the same two entities above with a written submission
(outlined within the permit) within 5 calendar days.
i. Include incident in the following training meeting.
8
3. STORMWATER MANAGEMENT CONTROLS
3.1. SWMP Administrator
The Local Contact and SWMP Administrator is (INSERT CONTACT NAME,
POSITION, COMPANY, and PHONE NUMBER).
(INSERT CONTACT) will be responsible for developing, implementing, maintaining,
and revising the SWMP. (INSERT CONTACT) will also be responsible for required
inspections and coordinating and documenting changes or repairs resulting from
inspections. (INSERT CONTACT) will be responsible for the training and enforcement
aspects of the SWMP and he is the first point of contact for any stormwater issues.
3.2. Identification of Potential Pollution Sources
The permit identifies 13 potential sources that must be evaluated for their potential to
contribute pollutants to stormwater discharge. These items have been evaluated below
for this project:
1) Disturbed and stored soil – YES – The construction will require that areas be
disturbed exposing soil including foundation construction, paving and repaving,
slope construction, and utility installation as shown on the plans. BMPs will
include silt fence and sediment control logs or inlet protection on existing and
proposed culverts and inlets, minimizing disturbance of existing vegetation and
hard surfaces, and slope roughening and tracking of slopes after disturbance and
prior to landscaping, paving, or building will be implemented.
2) Vehicle tracking of sediment – YES – The construction will require that subgrade
be prepared for pavement and that vehicles drive on unpaved surfaces to the
proposed buildings and utility improvement locations. BMPs will include a
policy that vehicles be clean prior to entering the site and, if they become muddy
during construction or earthwork activities, mud is removed by hand from the
vehicle prior to departing the site in an area near the vehicle tracking pad. Any
soil that is tracked from the site is to be disposed of in the trash dumpster by
sweeping or scraping the material off the street. Any muddy vehicle will use the
vehicle tracking pad prior to leaving the site.
3) Management of contaminated soil – NO – Soil borings do not indicate any
existing contamination.
4) Loading and unloading operations – YES – Chemicals and petroleum products
will be brought to the site. Anytime these are being transported, they will be in a
sealed container.
5) Outdoor storage activities – YES – Inert materials such as wood and stone will be
stored outside and will likely be covered with tarps or plastic, but are not pollutant
9
sources and are not covered by the permit. Chemicals and petroleum products
will be stored within the construction trailer or storage shed. Cement and mortar
bags (if not contained in a vehicle or storage shed) will be completely covered
with plastic to avoid contact with precipitation.
6) Vehicle and equipment maintenance and fueling – NO – Vehicle maintenance and
fueling, associated with construction of the proposed improvements, will not take
place. No fuel will be stored on site. (All existing fuel storage areas and devices
utilized with Natural Areas activities currently have secondary containment
controls functioning in place)
7) Significant dust or particulate generating processes – YES – Most of the 1.5 acre
site will be exposed from the over-lot grading of the project. In order to control
the dust or particulate generating process a water truck will be on site at all times.
The disturbed ground will be watered as needed to control dust from leaving the
site. The area of heavy construction is very limited and none of the operations are
expected to generate significant dust. All dust control measures shall be
completed in reference to the City’s Fugitive Dust Ordinance (Ordinance No. 044,
2016) and Dust Prevention and Control Manual.
8) Routine maintenance activities involving fertilizers, pesticides, detergents, fuels,
solvents, oils, etc. – YES – Fertilizers and pesticides will not be used. Any
cleaning or maintenance of small equipment will be required to be done within a
containment device (horse trough or small “kiddy pool” and the liquid disposed of
properly and legally.
9) On-site waste management – YES – The buildings and site construction (access
drive, concrete walks, and underground utilities) will result in construction waste.
A dumpster for trash and a dumpster for bulk recycling will be on the site. Waste
will be hauled to the dumpsters by hand or in loaders. Dumpsters will be hauled
off as needed. No construction waste will be left outside overnight without being
located in a dumpster. No construction debris (including broken concrete) may be
buried on the site.
10) Concrete truck/equipment washing – YES – A concrete washout will be provided
on site. This will be used for trucks and for any masonry / concrete tools.
11) Dedicated asphalt of concrete batch plants – NO – None on this project.
12) Non-structural waste sources such as worker trash and portable toilets – YES –
Trash dumpster will be available for worker’s trash and will be located near the
construction trailer and emptied weekly. Portable toilets will be staked on site
near the construction trailer.
13) Other areas where potential spills can occur – NO – The above 12 items are
adequate for the anticipated construction process.
CONTRACTOR TO UPDATE THE ABOVE INFORMATION WITH EXACT LOCATIONS
OF THE CONSTRUCTION TRAILER, VEHICLE TRACKING PAD, CONCRETE
WASHOUT, DUMPSTERS, AND PORTABLE TOILETS PRIOR TO COMMENCEMENT OF
CONSTRUCTION AND UPDATED AS NECESSARY THROUGHOUT THE
CONSTRUCTION SEQUENCE.
10
4. FINAL STABILIZATION AND LONG TERM STORMWATER
MANAGEMENT
Final stabilization shall be considered achieved once all proposed site improvements are
in place, all vegetation is established as identified on the landscape plan, all temporary
BMPs are removed, and the downstream conveyances are inspected and certified to be
clean and free from any construction debris resulting from the construction. Areas
controlled by grass sod will be considered established upon the completion of the sod
installation. Areas of seeding will be considered established at 70% of original coverage.
After stabilization, there are no other long term, permanent BMPs proposed within the
site other than routine maintenance of the site (landscape mowing, rain garden
maintenance, pavement maintenance, etc.).
5. INSPECTION AND MAINTENANCE
Site inspections will be performed to effectively address maintenance, repair, and
adequacy of BMPs. The site inspections will be performed by the SWMP Administrator
or his designee a minimum of once every fourteen (14) calendar days on active
construction sites and within 24 hours after a significant storm event (event causing
erosion). As part of the site inspections the inspector will keep documentation of all
inspections and BMP maintenance, including updated Site Maps indicating new BMPs or
the removal of BMPs since the previous inspection. Blank Site Maps will be utilized and
will be redlined by the SWMP Administrator throughout construction to note all BMPs,
pollutant sources, storage locations, etc.
Any maintenance, repair, or necessary installation of BMPs that are noted during the
inspection must begin immediately. The modifications shall be noted in the SWMP and
the action taken as a result of the inspection shall be noted and certified on or attached to
the original inspection report (date and time that the repair or change was started and
finished and a certification that it was done properly).
11
5.1. City of Fort Collins Standard Erosion and Sediment Control Notes
1) The City Stormwater Department erosion control inspector must be notified at
least 24 hours prior to any construction on this site.
2) All required BMPs shall be installed prior to any land disturbing activity
(stockpiling, stripping, grading, etc.). All of their required erosion control
measures shall be installed at the appropriate time in the construction sequence as
indicated in the approved project schedule, construction plans, and erosion control
report.
3) Pre-disturbance vegetation shall be protected and retained wherever possible.
Removal or disturbance of existing vegetation shall be limited to the area required
for immediate construction operations, and for the shortest practical period of
time.
4) All soils exposed during land disturbing activity (stripping, grading, utility
installations, stockpiling, filling, etc.) shall be kept in a roughened condition by
ripping or disking along land contours until mulch, vegetation, or other permanent
erosion control is installed. No soils in areas outside project street rights of way
shall remain exposed by land disturbing activity for more than thirty (30) days
before required temporary or permanent erosion control (e.g. seed/mulch,
landscaping, etc.) is installed, unless otherwise approved by the Stormwater
Department.
5) The property must be watered and maintained at all times during construction
activities so as to prevent wind-caused erosion. All land disturbing activities shall
be immediately discontinued when fugitive dust impacts adjacent properties, as
determined by the City Engineering Department.
6) All temporary (structural) erosion control measures must be inspected and
repaired or reconstructed as necessary after each runoff event and every 14 days in
order to assure continued performance of their intended function. All retained
sediments, particularly those on paved roadway surfaces, shall be removed and
disposed of in a manner and location so as not to cause their release into any
drainage way.
12
7) No stockpile shall exceed ten (10) feet in height. All soil stockpiles shall be
protected from sediment transport by surface roughening, watering, and perimeter
silt fencing. Any soil stockpile remaining after 30 days shall be seeded and
mulched.
8) City Ordinance prohibits the tracking, dropping, or depositing of soils or any other
material onto city streets by or from any vehicle. Any inadvertent deposited
material shall be cleaned immediately by the contractor.
5.2. City of Fort Collins Erosion Control Security Calculations
The cost of erosion control for the site was compared to the cost to reseed the entire site
and the greater cost was used to establish the erosion control escrow amount. The cost to
reseed the site is estimated at $2,250. Using a multiplier of 1.5 the erosion control
escrow amount would be $3,375. The site erosion control cost is estimated at $5,475.
Using a multiplier of 1.5 the erosion control escrow amount would be $8,212.50. The
larger sum of the Erosion Control cost and the Reseeding cost shall be used for the
escrow account. Therefore, the Erosion Control Escrow amount is $8,212.50. See Table
6.1 for a break-down of the costs associated with seeding and erosion control (numbers
provided are estimates and to be updated with final design).
13
Table 6.1: Erosion Control Cost Estimate (to be updated with final design)
ITEM QUANTITY UNIT COST/UNIT TOTAL COST
Sediment Control Log 425 LF $ 7.00 $ 2,975.00
Outlet Structure Protection 1 EA $ 200.00 $ 200.00
Concrete Washout 1 EA $ 800.00 $ 800.00
Construction Entrance/Vehicle Tracking Control 1 EA $ 1,500.00 $ 1,500.00
Subtotal $ 5,475.00
Contingency
(50%) $ 2,737.50
Total $ 8,212.50
CITY RESEEDING COST
Reseed/Mulch 1.5 ACRE $ 1,500.00 $ 2,250.00
Subtotal $ 2,250.00
Contingency
(50%) $ 1,125.00
Total $ 3,375.00
CALCULATED EROSION CONTROL ESCROW AMOUNT $ 8,212.50
Note: Minimum Escrow Amount is $3,000
14
6. SWMP IMPLEMENTATION
It is the responsibility of the contractor to operate and maintain all facilities and systems
of treatment and control which are installed to achieve compliance with the conditions of
the permit. This includes effective performance, adequate funding, adequate staffing and
training, etc. (see permit).
All personnel on the construction site who will be in a position to affect or be affected by
the SWMP shall be trained prior to beginning work. These individuals will be given
general orientation information regarding the project and SWMP, shown where the
SWMP is physically located, the SWMP will be explained to them and available for their
review, and the enforcement policy will be reviewed. After this training, a certification
that the employee or subcontractor’s employee is familiar with the document and its
procedures will be signed. Copies of these certifications are included in the Appendix.
Throughout the construction, as a part of a weekly safety meeting, the SWMP will be
reviewed with all attendees and any incidents discussed. All attendees shall be logged.
APPENDIX A—BMP DETAILS
B
APPENDIX B—EROSION CONTROL PLAN AND SITE MAP
C
APPENDIX C—CONSTRUCTION SEQUENCE
(Construction Phases) Mobilization Demolition Grading
Utilities
Installation
Flat work
Installation
Vertical
Installation
Landscape Demobilization
Best Management Practices (BMPs)
Structural "Installation"
Contour Furrows (Ripping / Disking)
Sediment Trap / Filter / Outlet Structure Protection*
Vehicle Tracking Pad*
Flow Barriers (Wattles)*
Inlet protection*
Rock Bags*
Rip Rap / Scour Stop
Collecting Asphalt / Concrete Saw Cutting Waste
Vegetative
Temporary Seeding Planting
Mulching/Sealant
Permanent Seeding Planting
Sod Installation
Rolled Products : Netting/Blankets/Mats Any time the site will sit dorment longer than 30 Days.
*All BMPs to be Removed once Construction is Complete, with the
exception of silt fencing, which shall remain in place until seeded
areas are established.
Any prior inlets that could use protecting
Any prior inlets that could use protecting
Any time the site will sit dorment longer than 30 Days.
Any time the site will sit dorment longer than 30 Days.
D
APPENDIX D—SOIL INFORMATION
Soil Map—Larimer County Area, Colorado
(Nix Farm - MA 2016)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/22/2016
Page 1 of 3
4491360 4491400 4491440 4491480 4491520 4491560 4491600
4491360 4491400 4491440 4491480 4491520 4491560 4491600
495900 495940 495980 496020 496060 496100 496140 496180 496220 496260 496300
495900 495940 495980 496020 496060 496100 496140 496180 496220 496260 496300
40° 34' 31'' N
105° 2' 54'' W
40° 34' 31'' N
105° 2' 36'' W
40° 34' 22'' N
105° 2' 54'' W
40° 34' 22'' N
105° 2' 36'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 25 50 100 150
Meters
Map Scale: 1:1,930 if printed on A landscape (11" x 8.5") sheet.
Warning: 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: http://websoilsurvey.nrcs.usda.gov
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
Map Unit Legend
Larimer County Area, Colorado (CO644)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
54 Kim loam, 3 to 5 percent slopes 0.6 7.5%
94 Satanta loam, 0 to 1 percent
slopes
0.0 0.0%
95 Satanta loam, 1 to 3 percent
slopes
7.2 92.4%
103 Stoneham loam, 5 to 9 percent
slopes
0.0 0.0%
Totals for Area of Interest 7.8 100.0%
Soil Map—Larimer County Area, Colorado Nix Farm - MA 2016
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/22/2016
Page 3 of 3
K Factor, Whole Soil—Larimer County Area, Colorado
(Nix Farm - MA 2016)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/22/2016
Page 1 of 3
4491360 4491400 4491440 4491480 4491520 4491560 4491600
4491360 4491400 4491440 4491480 4491520 4491560 4491600
495900 495940 495980 496020 496060 496100 496140 496180 496220 496260 496300
495900 495940 495980 496020 496060 496100 496140 496180 496220 496260 496300
40° 34' 31'' N
105° 2' 54'' W
40° 34' 31'' N
105° 2' 36'' W
40° 34' 22'' N
105° 2' 54'' W
40° 34' 22'' N
105° 2' 36'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 25 50 100 150
Meters
Map Scale: 1:1,930 if printed on A landscape (11" x 8.5") sheet.
Warning: 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
K Factor, Whole Soil
K Factor, Whole Soil— Summary by Map Unit — Larimer County Area, Colorado (CO644)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
54 Kim loam, 3 to 5 percent
slopes
.28 0.6 7.5%
94 Satanta loam, 0 to 1
percent slopes
.32 0.0 0.0%
95 Satanta loam, 1 to 3
percent slopes
.32 7.2 92.4%
103 Stoneham loam, 5 to 9
percent slopes
.28 0.0 0.0%
Totals for Area of Interest 7.8 100.0%
Description
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 Kw (whole soil)" indicates the erodibility of the whole soil. The
estimates are modified by the presence of rock fragments.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Layer Options (Horizon Aggregation Method): Surface Layer (Not applicable)
K Factor, Whole Soil—Larimer County Area, Colorado Nix Farm - MA 2016
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/22/2016
Page 3 of 3
Wind Erodibility Group—Larimer County Area, Colorado
(Nix Farm - MA 2016)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/22/2016
Page 1 of 3
4491360 4491400 4491440 4491480 4491520 4491560 4491600
4491360 4491400 4491440 4491480 4491520 4491560 4491600
495900 495940 495980 496020 496060 496100 496140 496180 496220 496260 496300
495900 495940 495980 496020 496060 496100 496140 496180 496220 496260 496300
40° 34' 31'' N
105° 2' 54'' W
40° 34' 31'' N
105° 2' 36'' W
40° 34' 22'' N
105° 2' 54'' W
40° 34' 22'' N
105° 2' 36'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 25 50 100 150
Meters
Map Scale: 1:1,930 if printed on A landscape (11" x 8.5") sheet.
Warning: 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
4L
5
6
7
8
Not rated or not available
Soil Rating Lines
1
2
3
4
4L
5
6
7
8
Not rated or not available
Soil Rating Points
1
2
3
4
4L
5
6
7
8
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: http://websoilsurvey.nrcs.usda.gov
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
Wind Erodibility Group
Wind Erodibility Group— Summary by Map Unit — Larimer County Area, Colorado (CO644)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
54 Kim loam, 3 to 5 percent
slopes
4L 0.6 7.5%
94 Satanta loam, 0 to 1
percent slopes
5 0.0 0.0%
95 Satanta loam, 1 to 3
percent slopes
5 7.2 92.4%
103 Stoneham loam, 5 to 9
percent slopes
6 0.0 0.0%
Totals for Area of Interest 7.8 100.0%
Description
A wind erodibility group (WEG) consists of soils that have similar properties
affecting their susceptibility to wind erosion in cultivated areas. The soils assigned
to group 1 are the most susceptible to wind erosion, and those assigned to group
8 are the least susceptible.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Lower
Wind Erodibility Group—Larimer County Area, Colorado Nix Farm - MA 2016
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/22/2016
Page 3 of 3
Hydrologic Soil Group—Larimer County Area, Colorado
(Nix Farm - MA 2016)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/22/2016
Page 1 of 4
4491360 4491400 4491440 4491480 4491520 4491560 4491600
4491360 4491400 4491440 4491480 4491520 4491560 4491600
495900 495940 495980 496020 496060 496100 496140 496180 496220 496260 496300
495900 495940 495980 496020 496060 496100 496140 496180 496220 496260 496300
40° 34' 31'' N
105° 2' 54'' W
40° 34' 31'' N
105° 2' 36'' W
40° 34' 22'' N
105° 2' 54'' W
40° 34' 22'' N
105° 2' 36'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 25 50 100 150
Meters
Map Scale: 1:1,930 if printed on A landscape (11" x 8.5") sheet.
Warning: 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
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
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: http://websoilsurvey.nrcs.usda.gov
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
Hydrologic Soil Group
Hydrologic Soil Group— Summary by Map Unit — Larimer County Area, Colorado (CO644)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
54 Kim loam, 3 to 5 percent
slopes
B 0.6 7.5%
94 Satanta loam, 0 to 1
percent slopes
B 0.0 0.0%
95 Satanta loam, 1 to 3
percent slopes
B 7.2 92.4%
103 Stoneham loam, 5 to 9
percent slopes
B 0.0 0.0%
Totals for Area of Interest 7.8 100.0%
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive precipitation
from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly
wet. These consist mainly of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well drained
soils that have moderately fine texture to moderately coarse texture. These soils
have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay layer
at or near the surface, and soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in their
natural condition are in group D are assigned to dual classes.
Hydrologic Soil Group—Larimer County Area, Colorado Nix Farm - MA 2016
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/22/2016
Page 3 of 4
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Hydrologic Soil Group—Larimer County Area, Colorado Nix Farm - MA 2016
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/22/2016
Page 4 of 4
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.
Hydrologic Soil Group—Larimer County Area, Colorado
(Nix Farm - MA 2016)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/22/2016
Page 2 of 4
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.
Wind Erodibility Group—Larimer County Area, Colorado
(Nix Farm - MA 2016)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/22/2016
Page 2 of 3
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: http://websoilsurvey.nrcs.usda.gov
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.
K Factor, Whole Soil—Larimer County Area, Colorado
(Nix Farm - MA 2016)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/22/2016
Page 2 of 3
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.
Soil Map—Larimer County Area, Colorado
(Nix Farm - MA 2016)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/22/2016
Page 2 of 3
1276-095-00 PondCalcs - Masterplan.xls - WQCV & Outlet StructurePage 1 of 3 Interwest Consulting Group
Atotal
(acres)
Apaved
(sq feet)
Aroof
(sq feet)
Awalk
(sq feet)
(ft)
INITIAL/OVERLAND
TIME (ti)
DESIGN
POINT
Sub-basin C5
( )
0 .33
0 . 395 1 . 1 5
S
C L
ti
−
=
t c = t i + t t 0 . 5
V = C v S w
V
L
tt 60
=
��
= 18 − 15� +
�
60 24� + 12 �
(sq feet)
Aroof
(sq feet)
Awalk
(sq feet)
Agravel/pavers
(sq feet)
Alawn
(sq feet)
Survey Area Data: Version 10, Sep 22, 2015
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.
Hydrologic Soil Group—Larimer County Area, Colorado
(Nix Farm Natural Areas Facility - Major Amendment 2016)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
10/6/2016
Page 2 of 4
___________________________________________
Contact: ____________________________________
Street address: _______________________________
___________________________________________
City/State/ Zip: _______________________________
Telephone: _______________ Fax: ______________
Certification:
By signing this permit I acknowledge that I am acting with
the knowledge, consent, and authority of the owners of the
property (including all owners having legal or equitable
interest in the real property, as defined in Section 1-2 of the
City Code; and including common areas legally connected
to or associated with the property which is the subject of
this application) without whose consent and authority the
requested action could not lawfully be accomplished.
Pursuant to said authority, I hereby permit City officials to
enter upon the property for purposes of inspection.
Name (please print): __________________________
Signature: ___________________________________
Telephone: ______________________
Foot Notes:
When a development project involves a change of use for a
building, the charge per square foot shall apply to the portion of
the overall building size for which the change of use is proposed,
provided that the new use generates more traffic than the existing
use, as determined by the current Institute of Transportation
Engineers Trip Generation. If the new use does not generate more
traffic than the existing use then the charge per square foot for
shall apply only to the net additional building size (if any).
These fees do not include the cost of filing fees for the recording of
the Development Agreement. When a Development Agreement or
Amendment Agreement is entered into the Developer shall be
responsible for the cost of recording the document. Said filing fees
shall be calculated and provided when the signed document is
returned to the City for signatures and filing.
*** This fee does not include the cost of filing fees. Filing
fees shall be determined at the time of final document
submittal and will be required prior to filing.
cc: Christie White, Engineering
Development Review Engineering
I certify the information and exhibits submitted are true and correct to the best of my knowledge and that in filing this application, I am acting with
the knowledge, consent, and authority of the owners of the real property, as those terms are defined in Section 1-2 of the City Code (including
common areas legally connected to or associated with the property which is the subject of this application) without whose consent and authority the
requested action could not lawfully be accomplished. Pursuant to said authority, I hereby permit City officials to enter upon the property for the
purpose of inspection, and if necessary, for posting of public notice on the property.
Name (Please PRINT): _______________________________________________________________________
Address:___________________________________________________________________________________
Telephone:___________________________________________________________________________
Signature: (and title showing authority to sign, if applicable)