HomeMy WebLinkAboutSEVEN GENERATIONS MULTIFAMILY - FDP230008 - DOCUMENT MARKUPS - ROUND 2 - EROSION CONTROL LETTER/REPORT
EROSION CONTROL REPORT
FOR
Seven Generations Multifamily
Prepared by:
Highland Development Services
6355 Fairgrounds Ave, Suite 100
Windsor, Colorado 80550
Phone: 970.674.7550
Prepared for:
Black Timber Builders
1303 W. Swallow Road
Fort Collins, CO 80525
Office: 970.282.7522
March 1, 2023
Job Number 22-1057-00
6355 FAIRGROUNDS AVE, SUITE 100, WINDSOR, COLORADO 80550 | PHONE 970.674.7550
March 1, 2023
City of Fort Collins Utilities – Stormwater Department
700 Wood Street
Fort Collins, CO 80522
RE: Erosion Control/Stormwater Management Plan for Seven Generations Multifamily
Fort Collins Stormwater Department,
We are pleased to submit for your review, this Erosion Control Report/Stormwater
Management Plan for the Seven Generations Multifamily housing project. 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,
Highland Development Services
Zach Wiele
Page i
TABLE OF CONTENTS
Table of Contents ............................................................................................................................. i
General Description and Location .................................................................................................. 1
Site Description and Location ...................................................................................................... 1
Site Soils ....................................................................................................................................... 2
BMPs for Stormwater Pollution Prevention ................................................................................... 5
Erosion and Sediment Controls ................................................................................................... 5
Materials Handling and Spill Prevention ..................................................................................... 7
Stormwater Management Controls ................................................................................................ 9
SWMP Administrator ................................................................................................................... 9
Identification of Potential Pollution Sources ............................................................................... 9
Final Stabilization and Long-term Stormwater Management ...................................................... 11
Inspection and Maintenance ........................................................................................................ 12
SWMP Implementation................................................................................................................. 13
Appendix ....................................................................................................................................... 14
Appendix A – BMP Details ........................................................................................................... A
Appendix B – Vicinity Map and Drainage & Erosion Control Plans ............................................. B
Appendix C – Construction Sequence ......................................................................................... C
Appendix D – Erosion Control Escrow Calculation ...................................................................... D
Appendix E – Soil Information ..................................................................................................... E
Appendix F – City of Fort Collins Standard Erosion Control Notes ..............................................F
Page 1
GENERAL DESCRIPTION AND LOCATION
SITE DESCRIPTION AND LOCATION
The project site is situated in the southeast quarter of Section 30, Township 7 North, Range 68
West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, in the State of
Colorado. The property consists of Lot 2 and the south 85 feet of the west 410 feet of Lot 4 of
the New Hampshire Subdivision, west of the intersection of Vermont Drive and Eastbrook
Drive. It is bounded by open space owned by the City of Fort Collins to the north, Eastbrook
Drive to the east, commercial development to the south, and the Union Pacific Railroad to the
west.
The site was previously developed as commercial office spaces with one building, the parking
lot, and all of the utility infrastructure currently constructed. The total site, including the
existing improvements and commercial office building is approximately 3.64 acres. The area of
proposed redevelopment, approximately 1.28 acres, is currently unimproved and was originally
approved with the Seven Generation Office Park for two additional commercial office buildings
and plaza space. The Seven Generations Multifamily proposes to redevelop this area with the
construction of a single 75-unit multifamily building and supporting access and plaza spaces.
The existing infrastructure, parking and utilities, is to generally be protected in place and
utilized to support the proposed redevelopment. The project site generally slopes from the
southeast to the northwest at approximately 2% toward an existing water quality pond in the
northwest corner of the property. The water quality pond was designed and constructed to
support the previous commercial office development and is well established with vegetation.
The intent is to protect the existing water quality pond and be utilized to provide water quality
enhancement for the existing improvements.
No wetlands are located within the area of proposed redevelopment.
The project site is not located within the FEMA floodway or floodplain and is within the non-
printed FEMA FIRM panel 08069C1000F, effective 12/19/2006. The site is within the City of Fort
Collins Foothill Master Drainage Basin and the City 100-yr floodplain is located along the west
and north sides of the property. The redevelopment area is outside of the City’s 100-yr
floodplain. Due to the vicinity of the site to this floodplain, timing of the peak runoff, and
proposed impervious area, on site detention was not required per the approval of the Seven
Generations Office Park.
The proposed redevelopment includes a single 75-unit multifamily building and plaza space that
will provide the required emergency access. The existing improvements will generally be
2
protected in place and will provide the required parking, utility services, and standard water
quality. A filtration gallery is proposed to provide additional the stormwater quality
enhancement and is intended to satisfy the low impact development (LID) requirement.
The site was previously analyzed within the “Final Drainage and Erosion Control Report for
Seven Generations Office,” prepared by Interwest Consulting Group, revised October 12, 2006.
SITE SOILS
The Seven Generations Multifamily redevelopment project site consists primarily of Nunn clay
loam and a small portion of Fort Collins loam both classified as Type C hydrologic group.
According to USDA/Natural Resource Conservation Group, Type C soils a have 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
also have a slow rate of water transmission.
Per the “Preliminary Subsurface Exploration Report, 3400 Eastbrook Drive, Fort Collins,
Colorado,” prepared by Earth Engineering Consultants, Inc. dated March 2, 2006:
“A thin mantle of topsoil/vegetation was encountered at the surface at boring locations. The
topsoil/vegetation was underlain by clayey sand and in boring B-1 and sandy lean clay in
borings B-2 and B-3. The clayey sand and sandy lean clay showed low swell potential in
laboratory testing at present moisture and density. The essentially granular soils extended to
the bottom of borings B-1 while moderately cohesive soils extended to depths of approximately
14 and 8 ft, respectively, in borings B-2 and B-3.
The lean clay soils in boring B-2 and B-3 were underlain in poorly graded sand and gravel. The
granular soils were loose to medium dense with cobbles observed with depth. The sand and
gravel extended to the bottom of the borings at depths of approximately 15 feet below present
site grades.”
Groundwater was also observed during the subsurface soil exploration:
“Observations were made while drilling and after completion of the borings to detect the
presence and depth to the hydrostatic groundwater table. At the time of drilling, no free
groundwater was observed in the test borings.”
3
SOIL TYPE PERCENT OF
SITE
HYDROLOGIC
SOIL GROUP1
K
FACTOR2
WIND
GROUP3
Fort Collins loam, 3-5% slopes 4.8% C 0.43 5
Nunn clay loam, 1-3% slopes 79.0% C 0.28 6
Nunn clay loam, wet, 1-3% slopes 16.2% C 0.24 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
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 E for the detailed on-site soil information from the NRCS Soil
Survey of Larimer County.
The anticipated sequence of construction shall progress as follows:
1) Installation of perimeter and offsite erosion control measures (mainly outlet
protection at the detention pond outlet structures). Other measures as required
for erosion control will be constructed throughout the project.
2) Clearing, stripping, stockpiling, and grading
3) Utility installation
4) Sub-grade preparation for the parking areas, drives and sidewalks
5) Curb, gutter, and sidewalks
6) Paving
7) Building construction (this may occur simultaneously with items 5 through 7)
8) 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.
4
The run-off coefficients associated with this project for onsite sub-basins are as follows:
TRIBUTARY
SUB-BASIN
AREA
(acres)
RUNOFF
COEFFIECENT
C2 C100
1A 0.35 0.74 0.93
1B 0.99 0.83 1.00
1A+1B 1.33 0.81 1.00
2 1.72 0.73 0.92
1A+1B+2 3.05 0.77 0.96
3 0.83 0.45 0.56
Totals 3.88 0.70 0.87
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) below. The
anticipated non-stormwater components of discharge with this project are landscape irrigation
return flows. The existing storm infrastructure to convey runoff includes swales, inlets, and
storm drainpipes. Stormwater water quality enhancement is achieved through the use of the
existing water quality pond and the proposed Filtration Gallery.
5
BMPS FOR STORMWATER POLLUTION PREVENTION
EROSION AND SEDIMENT CONTROLS
STRUCTURAL PRACTICES: Structural practices for the site will consist mainly of inlet protection,
sediment control logs, and rock socks 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 described further in this
report and as required to satisfy the conditions of the Permit.
Refer to Erosion & Sedimentation Control Plans for detailed BMP sequencing and maintenance
plans for the project through all stages of construction.
Soil stockpiles, if required, should be kept below the locally mandated maximum height and
surrounded with silt fencing or other acceptable means. If the storage of these soils is going to
be for an extended period of time, then consider temporarily seeding the soil to minimize soil
loss to wind and water erosion. Per the City of Fort Collins Stormwater Criteria Manual:
No soil stockpile shall exceed ten (10) feet in height. All soil stockpiles shall be protected
from sediment transport through the use of surface roughening, watering, and down
gradient perimeter controls. All soil stockpiles shall be protected from sediment
transport by wind in accordance with Municipal Code §12-150. All stockpiles shall be
flattened to meet grade or removed from site as soon as practical, and no later than the
completion of construction activities or abandonment of the project. All off-site stockpile
storage locations in City limits shall have a stockpile permit from the City Engineering
Department prior to using the area to store material. If frequent access from hardscape
to the stockpile is needed a structural tracking Control Measure shall be implemented.
No vehicular traffic is anticipated in/out of the disturbed area of the site during construction.
All constructions vehicles are to stage within the existing site parking lot. Adjacent roadways
will be kept clean with the understanding that if this becomes a problem, a vehicle tracking pad
(VTC) will be required. Vehicle tracking pads are intended to trap mud and sediment within
coarse grain material and provide clean access to public roadways. If required, wherever
6
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 and 50 ft from any stormwater or drainage course.
Seven Generations Multifamily proposes to utilize a Filtration Gallery to provide water quality
enhancement of the redevelopment area to satisfy the Low Impact Development requirements.
Inlet protection is required at the inlet of the filtration gallery. Sediment accumulation will need
to be observed throughout construction and during the establishment period and removed
periodically to ensure no excessive sediment enters the gallery.
Inlet protection, sediment control logs, and rock socks 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, rock socks, or gravel bags shall be placed at
existing and proposed inlets on and near the site as inlet protection. Inlet protection must be
inspected and maintained after every rainfall event that produces runoff. Sediment must be
removed and rocks replaced. Sediment control logs and rock socks will also be used as
perimeter protection at the toe of slopes and landscaped areas. Sediment control logs and rock
socks shall be installed immediately upon completion of over-lot grading.
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 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
7
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.
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.
8
g. Include incident in the following training meeting.
h. Provide information to the City of Fort Collins at the next regular inspection.
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.
9
STORMWATER MANAGEMENT CONTROLS
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.
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, and demolition required as shown on
the plans. BMPs will include silt fence and sediment control logs and inlet
protection on existing and proposed 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 – To our knowledge, there is not any
existing soil contamination on-site.
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 sources and are not covered by the permit. Chemicals and petroleum
10
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 – YES – Vehicle maintenance
and fueling, associated with construction of the proposed improvements, will
take place. No fuel will be stored on site.
7. Significant dust or particulate generating processes – YES – Most of the 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 or similar watering device will be
available 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 building and site construction 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.
THE CONTRACTOR IS 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 UPDATE AS NECESSARY THROUGHOUT
THE CONSTRUCTION SEQUENCE.
11
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 a vegetative density of 70%.
After stabilization, there are no other long term, permanent BMPs proposed within the site
other than routine maintenance of the site (landscape mowing, permeable paver maintenance,
pavement maintenance, etc.).
12
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).
13
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. 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.
14
APPENDIX
Appendix A – BMP Details
Appendix B – Vicinity Map, Phasing Plan, and Drainage & Erosion Control Plans
Appendix C – Construction Sequence
Appendix D – Erosion Control Escrow Calculation
Appendix E – Soil Information
Appendix F – City of Fort Collins Standard Erosion Control Notes
Appendix A
APPENDIX A – BMP DETAILS
REVISIONNO.BYDATEHIGHLANDDEVELOPMENT SERVICES6355 FAIRGROUNDS AVENUE, SUITE 100 | WINDSOR, CO 80550PHONE: 970.674.7550 | EMAIL: Info@Highland-DS.com | www.Highland-DS.comPREPARED BY OR UNDER THE
DIRECT SUPERVISION OF:
FOR AND ON BEHALF OF HIGHLAND
DEVELOPMENT SERVICES
REVIEW SET
NOT FOR
CONSTRUCTION
OFSHEET
DRAWN BY
CHECKED BY
DATE
SCALE (H)
HDS PROJECT #
SCALE (V)SEVEN GENERATIONS MULTIFAMILYEROSION CONTROL DETAILS3/1/23
NA
N/A
ZMW
JTC
22-1057-00
C4.00
7 9
CALL UTILITY NOTIFICATION
CENTER OF COLORADO
CALL 2-BUSINESS DAYS IN ADVANCE BEFORE YOU
DIG, GRADE OR EXCAVATE FOR THE MARKING OF
UNDERGROUND MEMBER UTILITIES.
before you dig.CallKnow what's below.
R
Appendix B
APPENDIX B – VICINITY MAP AND DRAINAGE & EROSION CONTROL PLANS
SITE
E. DRAKE RD
UNION PACIFIC RAILROADS. TIMBERLINE RDE. HORSETOOTH RDS. LEMAYAVEVicinity Map
Scale: 1" = 1000'
PROJECT DATUM: NAVD88
CITY OF FORT COLLINS BENCHMARK #43-01
EAST SIDE OF TIMBERLINE ROAD, AT THE SOUTH ENTRANCE TO C.S.U. RIGDEN FARM, ON THE NORTH END OF THE
HEAD WALL OF A STORM DITCH
ELEV= 4937.02
CITY OF FORT COLLINS BENCHMARK #12-93
NORTHWEST CORNER OF HORSETOOTH ROAD AND TIMBERLINE ROAD, ON A SIGNAL POLE BASE
ELEV= 4957.08
PLEASE NOTE: THIS PLAN SET IS USING NAVD88 FOR A VERTICAL DATUM. SURROUNDING DEVELOPMENTS HAVE
USED NGVD29 UNADJUSTED DATUM (PRIOR CITY OF FORT COLLINS DATUM) FOR THEIR VERTICAL DATUMS.
IF NGVD29 UNADJUSTED DATUM (PRIOR CITY OF FORT COLLINS DATUM) IS REQUIRED FOR ANY PURPOSE,
THE FOLLOWING EQUATIONS SHOULD BE USED:
NGVD29 UNADJUSTED DATUM (PRIOR CITY OF FORT COLLINS DATUM) = 4937.02 (NAVD88 DATUM) - 3.18'
NGVD29 UNADJUSTED DATUM (PRIOR CITY OF FORT COLLINS DATUM) = 4957.08 (NAVD88 DATUM) - 3.19'
NYLOPLAST DUCTILE IRONDO NOT POLLUTE DRAINS TO WATERWAYS
NYLOPLAST DUCTILE IRON
DO NOT POLLUTE DRAINS TO WATERWAYS
NYLOPLAST DUCTILE IRON
DO NOT POLLUTE DRAINS TO WATERWAYS
100-YR FP
100-YR FP100-YR FPVERMONT
DRIVE
(54' ROW)EASTBROOK DRIVE(54' ROW)LOT 1
NEW HAMPSHIRE SUBDIVISION
EXISTING
COMMERCIAL BUILDING
FFE = 4950.70
SEVEN GENERATIONS
MULTIFAMILY
BUILDING
FFE = 4952.25UNION PACIFIC RAILROADTRACT A
TIMBERLINE VILLAGE PUD
(City of Fort Collins)
(U&DE)
APPROX LIMITS OF
REDEVELOPMENT AREA
& DISTURBED AREA
56,500± SQFT
(1.30± ACRES)
FILTRATION GALLERY
48~SC-160LP STORMTECH CHAMBERS
EXISTING STANDARD
WATER QUALITY POND
EX TRASH
ENCLOSURE
(MODIFIED)REVISIONNO.BYDATEHIGHLANDDEVELOPMENT SERVICES6355 FAIRGROUNDS AVENUE, SUITE 100 | WINDSOR, CO 80550PHONE: 970.674.7550 | EMAIL: Info@Highland-DS.com | www.Highland-DS.comPREPARED BY OR UNDER THE
DIRECT SUPERVISION OF:
FOR AND ON BEHALF OF HIGHLAND
DEVELOPMENT SERVICES
REVIEW SET
NOT FOR
CONSTRUCTION
OFSHEET
DRAWN BY
CHECKED BY
DATE
SCALE (H)
HDS PROJECT #
SCALE (V)SEVEN GENERATIONS MULTIFAMILYDRAINAGE & EROSION CONTROL PLAN3/1/23
1" = 20'
N/A
JTC
JTC
22-1057-00
C2.00
4 9
CALL UTILITY NOTIFICATION
CENTER OF COLORADO
CALL 2-BUSINESS DAYS IN ADVANCE BEFORE YOU
DIG, GRADE OR EXCAVATE FOR THE MARKING OF
UNDERGROUND MEMBER UTILITIES.
before you dig.CallKnow what's below.
R
N
W E
S
0
SCALE: 1" = 20'
40201020
BASIN COEFFICIENT (100-YR)
BASIN DESIGNATION
BASIN AREA
DESIGN POINT
DRAINAGE FLOW ARROW
DRAINAGE BASIN BOUNDARY
DRAINAGE BASIN FLOW PATH
LEGEND
EXISTING MAJOR CONTOUR
EXISTING MINOR CONTOUR
PROPOSED MAJOR CONTOUR
PROPOSED MINOR CONTOUR
ROCK SOCK
INLET PROTECTION
SEDIMENT CONTROL LOG
CONCRETE WASHOUT AREA
NOTES
1.THE NATURAL HABITAT BUFFER ZONE (NHBZ) IS INTENDED TO BE MAINTAINED
IN A NATIVE LANDSCAPE. PLEASE SEE SECTION 3.4.1 OF THE LAND USE
CODE FOR ALLOWABLE USES WITHIN THE NATURAL HABITAT BUFFER ZONE.
2.CONTRACTOR TO PROVIDE AND MAINTAIN ALL NECESSARY EROSION
CONTROL MEASURES PRIOR TO AND THROUGHOUT CONSTRUCTION.
PLACE EROSION CONTROL PROTECTION AT ALL EXISTING INLETS
DOWNSTREAM FROM THE CONSTRUCTION AREA. EROSION CONTROL
PROTECTION SHALL REMAIN IN PLACE UNTIL CONSTRUCTION IS COMPLETE
AND ALL DISTURBED GROUND IS ADEQUATELY VEGETATED WITH OWNER'S
APPROVAL FOR REMOVAL.
3.THE EXTENT OF EROSION CONTROL PROTECTION SHALL BE OBSERVED AND
ADJUSTED AS NEEDED DURING CONSTRUCTION BASED ON SITE
CONDITIONS AND THE PERFORMANCE OF THE EROSION CONTROL
CONTROL MEASURES SHOWN, TO SUPPLY SUFFICIENT EROSION CONTROL
AND MINIMIZE DOWNSTREAM WATERWAY POLLUTION.
4.LIMIT DISTURBANCE TO AREAS WITHIN EROSION CONTROL BOUNDARIES.
ADJUST EROSION CONTROL BOUNDARIES AS NECESSARY TO ADEQUATELY
COMPLETE PROPOSED WORK. ALL DISTURBED AREAS SHALL BE PREPARED
(SEEDED & MULCHED, SURFACE ROUGHENING, ETC.) TO MINIMIZE EROSION
POTENTIAL AND SOIL MIGRATION.
5.STORMWATER MANAGEMENT PLAN SHALL BE PREPARED AND SUBMITTED
BY CONTRACTOR PRIOR TO CONSTRUCTION COMMENCEMENT.
6.SEE LANDSCAPE PLAN FOR REVEGETATION METHODS AND DETAILS.
DURING CONSTRUCTION, ANY SOIL DISTURBED AND NOT UNDER ACTIVE
CONSTRUCTION SHALL BE SEEDED AND MULCHED PER CITY STANDARDS.
7.ANY DISTURBED LAND MUST RECEIVE SURFACE ROUGHENING, INCLUDING
BUT NOT LIMITED TO SLOPED AREAS.
8.NO VEHICULAR TRAFFIC IS ANTICIPATED IN/OUT OF THE REDEVELOPMENT
AREA DURING CONSTRUCTION. ALL CONSTRUCTION VEHICLES ARE TO
STAGE WITHIN THE EXISTING SITE PARKING LOT.
9.REFERENCE SEVEN GENERATIONS MULTIFAMILY DRAINAGE REPORT.
10.REFERENCE SHEET 7 FOR EROSION CONTROL DETAILS.
Appendix 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"
Silt Fence Barriers*
Contour Furrows (Ripping / Disking)
Sediment Trap / Filter*
Vehicle Tracking Pad*
Flow Barriers
Inlet protection*Any prior inlets that could use protecting
Rock Bags*Any prior inlets that could use protecting
Terracing
Rip Rap
Collecting Asphalt / Concrete Saw Cutting Waste
*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.
Vegetative
Temporary Seeding Planting Any time the site will sit dorment longer than 30 Days.
Mulching/Sealant Any time the site will sit dorment longer than 30 Days.
Permanent Seeding Planting
Sod Installation
Rolled Products : Netting/Blankets/Mats Any time the site will sit dorment longer than 30 Days.
Appendix D
APPENDIX D – EROSION CONTROL ESCROW CALCULATION
3/1/2023
Project:Disturbed Acres:1.30
EROSION CONTROL BMPs Units
Estimated
Quantity
Unit
Price
Total
Price
L.F. 0 $2.50 $0.00
each 12 $150.00 $1,800.00
L.F. 410 $2.00 $820.00
each 0 $500.00 $0.00
each 1 $300.00 $300.00
each 0 $800.00 $0.00
LS 1 $2,500.00 $2,500.00
Sub-Total: $5,420.00
1.5 x Sub-Total: $8,130.00
Amount of security: $8,130.00
AC 1.30 $2,000.00 $2,600.00
Sub-Total: $2,600.00
1.5 x Sub-Total: $3,900.00
Amount to Re-seed: $3,900.00
Minimum escrow amount: $3,000.00
Erosion Control Escrow:$8,130.00
Seeding
Miniumum Escrow Amount
Final Escrow Amount (Maximum between BMP, Reseeding and Minimum Escrow)
“The amount of the security must be based on one and one-half times the estimate of the cost to install the approved measures, or one and one-half times
the cost to re-vegetate the disturbed land to dry land grasses based upon unit cost determined by the City's Annual Revegetation and Stabilization Bid,
whichever is greater. In no instance, will the amount of security be less than one thousand five hundred dollars ($1,500) for residential development or
three thousand dollars ($3,000) for commercial development”
Vehicle Tracking Control Pad
Inlet Protection
Outlet Protection
Street Sweeping and Cleaning
Reseeding Amount
Erosion and Sediment Control Escrow/Security Calculation
for The City of Fort Collins
Seven Generations Multifamily
BMP Amount
Silt Fence
Rock Sock
Sediment Control Log
3/1/2023 10:58 AM G:\Projects\22-1057-00 Seven Gen (FC)\03 Design Documents\Drainage\Erosion Control\22-1057-00 - Erosion Control Escrow.xls