HomeMy WebLinkAboutSite Certifications - 11/07/20188/16 Page 1
OVERALL SITE and DRAINAGE CERTIFICATION
Commercial, Multi-Family and Subdivision Certification Form and Checklist
Project Name:
Date:
Building Permit Numbers:
(Commercial or multi-family)
Per the requirement in Fort Collins Stormwater Criteria Manual (FCSCM) Volume 1, Section 6.11, please fill in
all applicable items in this Certification Form for Commercial, Multi-Family and Overall Single Family sites.
NOTE: several items must be verified during construction. A copy of the approved grading plan must be
submitted with the as-built grading plan. (As-built elevations must be written in red next to the approved
elevations.)
•Use “Yes” for items completed as described.
•Use “N/A” for items that are not applicable to the site being certified.
•If any blanks are “No,” attach an explanation referencing the item number below.
Attach an explanation or description of the as-built condition for any items listed or for anything not listed but
shown on the approved construction plans.
Provide an as-built redline or Mylar drawing with the following:
I.Water Quality and Quantity Detention Basin Certification - FCSCM Vol.2, Ch.10
For multiple detention basins on a site, provide the following for each basin separately:
A. Volume: As-built topographic verification is attached at 1-foot (or less) contour intervals and
volume verification calculations for the water quality capture volume and the 100-year detention storage
volume.
1. Detention basin topography was prepared by a professional land surveyor registered in the state
of Colorado.
2.Both proposed and as-built contours are shown on the same plan sheet (dashed lines for
proposed and solid lines for as-built).
3.All critical spot elevations as shown on the approved construction plans have been verified and
the as-built elevations are shown on the plan sheet.
4.Stage-storage-discharge tables are provided on a separate document.
5.Verification that designed drain time is in compliance with Colorado Revised Statute § 37-92-
602(8) is attached and has been uploaded to the Statewide Compliance Portal
(tinyurl.com/COCompliancePortal) for approval. Uploaded documents must include:
a.The cover sheet from the approved drainage report
b.The stamped certification page from the approved drainage report
c.As-built topographic survey
d.Stamped certification page from the Overall Site & Drainage Certification
e.PDF output from the Stormwater Detention and Infiltration Design Data Speadsheet
COUNTRY CLUB CORNERS SIXTH FILING, LOT 1 & 2
10/30/2018
Yes
Yes
No
Yes
N/A
Yes
Documents have not been uploaded, but items c,d,e are provided in this document.
Accepted 11/7/2018
WL
B1702385
8/16 Page 2
B.Water Quality and Quantity Detention Basin Grading: Attached is as-built verification that there is
a minimum 2% positive fall into the concrete trickle pans or flow-line(s) from all areas in the bottom of
the detention pond. If there is a “soft pan” in the flow-line, all areas still must meet the minimum 2%
grade requirement.
1.Low Flow: Choose one of the following detention basin low flow options as applicable:
a. Turf swale for low flow path in detention basin.
There is a minimum 2% grade in the flow-line(s) of the detention basin. The flattest as-built grade
is .
b.Concrete pan for low flow in detention basin.
There is a concrete pan installed that meets the grades as shown on the approved construction
plans. (Show as-built spot elevations.)
c.Soft pan for low flow in detention basin.
•Verify and document the soft pan material gradation, trench width and depth - to be verified
during construction by engineer. Picture documentation is preferred or engineer’s statement of
visual inspection and compliance. (Choose one below.)
o There is a soft pan with an underdrain installed that meets the design on the approved
construction plans. (Show the underdrain grades, bedding material, geotextile, spot elevations,
bends, cleanouts, etc.)
o There is soft pan installed without an underdrain but there is a type A or B soil. The soil
type must be documented by supplying verification from a registered professional geotechnical
engineer.
NOTE: Spot elevations are to be within 0.2 ft. +/-.
2. Side Slopes: The as-built side slopes of the detention basin have been calculated and are shown.
Indicate the side slope with an arrow and a numerical value (e.g., 6.25:1). The maximum slope allowed
is 4:1. Small areas of 3:1 may be acceptable, but slopes steeper than 3:1 must be stabilized or re-
graded. Provide documentation if a variance was granted for steeper slopes during the design process.
3.Spillway Certification: The following items must be field verified:
a.The location of the spillway is indicated on the as-built plan.
b.The width of the spillway is indicated on the as-built plan.
c.The elevation(s) of the spillway is shown on the as-built plan.
d.A concrete ribbon defines the location and grade of the spillway.
e.There is downstream scour protection in the spillway as per the construction plans. Indicate
type: (riprap size “D50” gradation and bedding type, geotextile, buried
riprap with inches of bury, etc.).
f.There are no obstructions in the spillway, such as trees, bushes, sidewalks, landscape
features, rocks, etc.
No
N/A
N/A
N/A
N/A
No
N/A
N/A
N/A
N/A
N/A
N/A
0%
N/A
N/A
YES
NO
8/16 Page 3
4.Outlet Structure Certification
a.The orifice plate for the approved release rate is installed with the correct size and location of
the orifice.
b.The orifice plate for the water quality outlet is installed with the correct hole size, number of
rows and columns of holes.
c.The bottom hole on both the water quality and quantity outlets are at the bottom of the plate
so no water ponds in front of the plate.
d.The well screen is the correct material and is installed as shown on the construction plans.
e.100-year overflow grate elevation is . (Elev. A on detail D-46)
f.The top elevation of the water quality capture volume is . (Elev. B on detail
D-46)
g.Overflow grate is made of the correct material, has the correct bar spacing, is hinged at the
top and bolted at the bottom.
h.The bottom of the outlet box has no obstructions or misalignments that will cause it to retain
runoff water and is sloped at 2% towards outlet.
II.Channels/Swales - FCSCM Vol.1, Ch.7, Sect.3&4
A. Capacity: The as-built capacity of all the major channels and swales has been verified. They meet
or exceed capacity requirements shown in the approved drainage study for this project.
1.All swales are located within the drainage easements as shown on the construction plans.
2.Longitudinal slopes and side-slopes (cross-sections) have been verified. Design criteria requires
longitudinal slopes of 2% min. (on vegetated swales) and side-slopes no steeper than 4:1. If these
criteria are not met, the certification engineer will write a justification and propose mitigation for each
instance or have the issues corrected. If variances to these criteria have previously been approved and
are shown on the construction plans, no justification is needed.
3.As-built spot elevations on channels/swales are shown that correspond to spot elevations
shown on the approved construction plans.
4.All permanent erosion control measures are installed as shown on the approved construction
plans (e.g., drop structures, riprap, TRMs, etc.). (Include pictures and verification of the materials used
as part of this verification.)
5.All pans, curbs, storm pipes or other appurtenances appropriately tie into each other in the
system. (Pictures at tie-in points suggested.)
6.The minimum freeboard is provided for all channels and swales as shown on the approved
construction plans or as identified in the approved drainage study. (Show the freeboard provided on
the cross-sections as on the construction plan set or attached as separate documentation.)
7.The low flow portion of all channels or swales is clear of obstructions. (No landscaping, trees,
shrubs, sod, etc. infringe on the low flow portion of channels or swales.)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Yes
No
Yes
Yes
N/A
Yes
N/A
8/16 Page 4
III.Storm Pipes (aka storm drains) - FCSCM Vol.1, Ch.6, Sec. 4
A. Storm Drain Pipe Capacity: The as-built capacity of all pipes installed on this project has been
verified and meets or exceeds the capacity requirements shown in the approved drainage study for this
project.
1.All storm drain pipe sizes and materials have been verified and are in conformance with the
approved construction plans. (Indicate on the plan and profile sheets that they have been verified.)
Material and size substitutions must be approved prior to installation. If a pipe size or material was
changed during construction, the certification engineer must attach the approval documents or supply
them with this certification. Approval documents must include a calculation documenting the capacity
equivalency (equal or greater) of the substituted size.
2.The longitudinal slope of the pipe is as shown on the approved construction plans. The
acceptable minimum slope is 0.4%. All slopes flatter than the designed slope on the construction plans
must be justified with capacity calculations on an attached sheet.
3.The as-built invert elevations have been verified and are shown on the plan and profile sheets of
the approved construction plans.
B.Storm Drain Pipe Installation Requirements: All pipes are installed in accordance with the
approved construction plans.
1.The minimum cover requirements for all pipes have been met as shown on the approved
construction plans. These will be called out in critical locations.
2.All encasements and clearances as specified on the approved construction plans have been met.
3.Any specific joint types or construction methods specified on the approved construction plans
have been met. (List on a separate sheet and attach to this certification.)
IV.Concrete Pans - FCSCM Vol.1, Ch.7, Sec.4.1.3.4
A. Construction/Installation: All concrete pans have been constructed in accordance with the
approved construction plans.
1.The concrete pans are the correct size/width as shown on the approved construction plans.
2.The longitudinal slopes of the pans are as shown on the approved construction plans. The
certification engineer must justify or mitigate longitudinal slopes less than the minimum of 0.4% unless
a flatter slope was approved and is shown on the approved construction plans. Provide mitigation or
justification by separate document.
3.The cross-section of the pan is as shown on the construction plans. (Specifically, the pan cross-
section is “V” shaped and meets the side slope shown on the detail.)
4.The concrete pans are a minimum of 6 inches thick without reinforcement and a minimum of 4
inches thick with a minimum of 6X6-W14xW14 reinforcement per detail D20B and D20C. (Provide
documentation of the reinforcement used if different than shown on the details or on the approved
construction plans.)
5.The spot elevations shown on the concrete pan(s) have been verified and are shown on the as-
built drawings.
Yes
Yes
No
No
Yes
N/A
N/A
N/A
No
No
No
No
No
8/16 Page 5
V. Storm Drain Inlets - FCSCM Vol.1, Ch.6, Sec. 3
A. Construction/Installation: All storm drain inlets have been constructed in accordance with the
approved construction plans.
1.The size and type of inlets are consistent with the inlets shown on the approved construction
plan. Indicate by writing “Verified” on each inlet on the plan sheet or list on a separate document the
inlet number(s), type and size (length). If the inlet installed is other than the one on the approved
construction plan detail sheet, provide the name and source of the detail with justification for equal or
better capacity.
2.The size of the inlet opening is consistent with the approved detail. (Check height and width.)
3.The elevation of the grate (if applicable) is at the elevation shown on the street profile or as
indicated by a spot elevation on the construction plans.
4.The as-built invert elevations of all pipes entering and leaving the inlet are shown on the plan
and profile sheets within construction tolerance of 0.2 feet. If substantially different, provide
justification and capacity calculations to show the capacity is not affected or propose mitigation.
5.The as-built size of the inlet box is as shown on the construction plans or an explanation or
justification is attached.
6.All Type C, R, 13 and 16 inlet covers are stenciled or stamped with the following (or an
equivalent) designation: NO DUMPING – DRAINS TO POUDRE RIVER.
VI.Culverts - FCSCM Vol.2, Ch.9
A. Construction/Installation: All culverts have been constructed and/or installed in accordance with
the approved construction plans.
1.All culvert sizes have been verified as indicated on the as-built construction plans as correct.
2.The culvert material type for all culverts installed is as on the approved construction plans and is
indicated on the as-built plans.
3.The as-built invert “in and out” elevations have been verified and are indicated on the as-built
construction plans.
4.The culvert headwalls or wing walls have been installed as shown on the approved construction
plans. Headwalls or wing walls may be needed in the as-built conditions onsite if the slopes adjacent to
the culvert are greater than 4:1. Please note areas needing stabilization in the certification narrative.
An alternative to consider is a turf reinforcement mat (TRM).
VII.Sub-Drains
A. Construction/Installation: All sub-drains shown on the construction plans have been installed in
accordance with those plans. Sub-drains installed with the sanitary sewer are to be verified on the
sanitary sewer plan and profile sheets of the construction plans. (NOTE: Indicate any sub-drains installed
after the plans were approved on the as-built plans.)
1.The size of the sub-drains are as approved on the construction plans and are indicated on the as-
built plans.
2.The type of sub-drain, in particular the perforated and non-perforated sections of the drain, are
as indicated on the approved construction plans.
Yes
Yes
Yes
No
No
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Yes
No
No
8/16 Page 6
3.The cover requirements per the construction plans are provided.
4.The cleanouts have been installed at the locations shown on the construction plans and are
accessible for cleaning. (Cleanouts can be buried a maximum of 6 inches deep with their locations
marked.)
5.The backfill materials for sub-drains are as shown on the approved construction plans. (This
includes the type, depth and width.)
6.The geo-textile liner completely wraps the sub-drain and the permeable backfill material unless
shown otherwise on the approved construction plans. (Sub-drain pipe wrapped in a sock filter material
is accepted only if approved prior to installation.)
VIII.Curb Cuts
A. Construction: All curb cut openings are constructed in accordance with the approved construction
plans.
1.The size (width) of the curb cut opening is as shown on the approved construction plans.
2.The curb cut openings tie into a downstream swale, pipe, or other appurtenances with a smooth
transition and there no obstructions such as riprap or sod impeding the flow downstream of the curb
cut.
IX.Sidewalk Culverts & Chases
A. Construction/Installation: All sidewalk culverts have been installed at the locations shown on the
approved construction plans.
1.The size (width and length) of the culverts are as shown on the approved construction plans.
2.The cover plate is a minimum 5/8-inch galvanized plate bolted to a galvanized angle iron per the
detail shown on the approved construction plans or per the City’s detail.
3.The sidewalk culvert invert “in and out” elevations have been verified and are indicated on the
as-built plans.
4.The sidewalk culvert opening is as shown on the approved construction plans or per the City’s
detail.
5.There is a smooth transition both on the inlet and outlet ends of the sidewalk culvert with no
obstructions such as riprap or sod impeding the flow into or out of the sidewalk culvert.
X. Site Grading
A. Construction: All common open spaces have been graded in accordance with the approved
construction plans.
1.The grading on all common open spaces bordering private lots has been verified as correct and
the as-built rear lot corner elevations have been shown on the as-built plans.
N/A
N/A
N/A
N/A
Yes
Yes
Yes
N/A
N/A
N/A
N/A
N/A
N/A
Yes
N/A
8/16 Page 7
2.The as-built contours for “overlot grading” are shown on the as-built construction plans for all
common open spaces, tracts, outlots, etc. If not in compliance, please attach a narrative describing the
situation for noncompliance and when it may be corrected. An escrow for overlot grading may be
required. (NOTE: Residential Lot Grading Certification is a separate process from this Overall Site
Certification. It is understood that residential lots will be brought to final grade once the foundation is
backfilled so they may be lower than the plan shows at this Overall Site Certification stage.)
3.All turf reinforcement mats (TRMs) have been installed as shown on the approved construction
plans and the slopes are stabilized.
XI.Riprap - FCSCM Vol.1, Ch.7, Sec.4.4.4.3
A. Construction: All riprap has been installed in the locations and sizes indicated on the approved
construction plans.
XII.Permanent Erosion Control Fabric - FCSCM Vol.1, Ch.7
A. Construction: All fabric has been installed in the locations and sizes indicated on the approved
construction plans.
1.All fabric was installed per the details on the approved construction plans.
XIII.Post-Construction Site Cleanup - FCSCM Vol.3, Ch.7
A. Construction: All construction debris and obstructions of any kind have been removed from
drainage paths.
1.All construction debris has been removed except in staging area(s).
2.All ruts have been smoothed out in all construction areas.
3.All areas needing reseeding have been identified and future stabilization goals have been
coordinated with the Erosion Control Inspector and in accordance with FCSCM Vol.2 Chapter 12. Note
the area needing stabilization in the narrative.
XIV.Certification of Other Permanent BMPs - FCSCM Vol.2, Ch.8, Sec.2 & FCSCM Vol.2, Ch.12
A.The construction of channel drop structures is in accordance with the approved plan both in
location, horizontal dimensions and cross-section.
XV.Certification of LID and Water Quality Facilities - FCSCM Vol.3, Ch.4
A.Attached are the During Construction Inspection Checklist for Low Impact Development (LID) and
other items to be verified during construction, along with pictures and other required documentation.
N/A
Yes
N/A
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
8/16 Page 8
XVI. Certification and Erosion Control Measures
A. All temporary erosion control measures shall be removed upon stabilization. If at the time of preparing
this certification there are any erosion control measures still remaining on the site, please note them in
the narrative and verify that they need to remain at this time. If in doubt as to the need for any control
measure, please consult with the Erosion Control Inspector at 970-221-6700.
XVII.Statement of Compliance
A. This certification is signed and stamped. By signing this form, the engineer(s) attests that he/she has
visited and observed the site, and to the best of his/her knowledge, the as-built conditions of the drainage
facilities are as described in the above form and in the enclosed as-built plans.
B.Failure to properly disclose all known information could result in the rejection of this certification and
prevent the release of any and all Stormwater Utility permit holds on Building Permits and/or Certificates
of Occupancy within this development.
XVIII.Signature and Stamp by a Colorado-Registered Professional Engineer
Engineer’s contact information:
Name:
Email:
Phone:
Company:
Address:
PE Stamp
Jason T. Claeys
jclaeys@interwestgrp.com
(970) 347-8917
Interwest Consulting Group
1218 W. Ash Street, Suite A
Windsor, CO 80550
1218 W. ASH, STE. A, WINDSOR, COLORADO 80550
TEL. 970.674.3300 – FAX 970.674.3303
October 30, 2018
Mr. Wes Lamarque
Fort Collins Utilities
700 Wood Street
Fort Collins, CO 80522
Via email: wlamarque@fcgov.com
Re: Country Club Corners Sixth Filing – Lots 1 and 2
Clarification of Overall Site and Drainage Certification Items
Dear Wes,
Please accept this letter in support of the checklist items from the Certification of Overall Site and
Drainage Items regarding items noted as not being in conformance with the checklist descriptions.
As a result, we offer the following for your review and approval:
Item I.A.2 – The attached grading plan shows proposed contours, while the attached as-built survey
shows the as-built contours.
Item I.B – There is an area near the outlet of the interim detention pond that is sloped at less than
2% into the flowlines leading to the outlet, however the slopes do appear to be at least 1%.
Item I.B.1.a – There is an area near the outlet of the interim detention pond where the flowlines
are less than 2%. Some ponding occurs before outfalling into the existing outlet pipe.
Item I.B.2 – The as-built side slopes of the interim detention basin have been calculated, but are
not shown on the as-built survey. The southern bank of the interim detention pond as well as some
small areas appear to have a 4:1 slope, but they do not appear to exceed a 3:1 slope.
Item II.A.3 – As-built spot elevations on swales are shown on the as-built survey, but they don’t
necessarily correspond with the design grades. However, swales outside of the interim detention
pond that are less than 1% may incur only minimal ponding before reaching a point of positive
drainage. The downspouts from building roofs are directed to storm drain pipes and area inlets
are also provided in this area.
Items III.A.1-3 – Based on site observations, it appears the pipe sizes and material are correct. The
longitudinal pipe slopes are in general conformance with the approved construction plans. The as-
built invert elevations have been verified and are shown on the as-built plan and profile sheets that
are included with this document.
Country Club Corners Sixth Filing, Lot 1 &2 – Overall Site and Drainage Certifications
October 30, 2018
Page 2 of 3
Item IV.A – The private concrete pans do not appear to be constructed per the plan details and do
not have a defined flowline.
Item IV.A.1 – The private concrete pans that were constructed do not appear to be the correct
size/width as shown on the approved construction plans; the “V” shape is not visible.
Item IV.A.2 – The private concrete pans that were built do appear to have longitudinal slopes that
are within tolerance of the longitudinal slopes on the approved construction plans.
Item IV.A.3 – The cross-section of the private pans that were constructed do not appear to have
the cross-section of the pan that is shown on the construction plans. The “V” shape does not meet
the side-slope shown on the detail of the construction plans.
Item IV.A.4. – The thickness of the private concrete pans that were constructed and their
reinforcement are unknown as all sides of the pan are surrounded by concrete. Documentation of
the thickness and the reinforcement would have to be provided by the contractor to make this
determination.
Item IV.A.5 – The spot elevations shown on the private concrete pans that were constructed have
been verified and are shown on the as-built drawings, but it appears that not all of the pans were
constructed.
Item V.A.1 – The inlets were verified during a site visit. Some of the inlets do not appear to be the
exact type shown on the construction plans, but they are generally in conformance. A separate
document detailing the characteristics is not necessary.
Item V.A.3 – Not all inlets were surveyed. The elevations of the inlet grates that were surveyed
are not all at the design elevations shown on the construction plans. Based on site observations,
the inlets appear to provide proper drainage and are generally in conformance with the construction
plans.
Item V.A.4 – Of the pipes that were surveyed, the as-built invert elevations of the pipes entering
and leaving inlets are not within 0.2 feet of the construction plans. They are however generally in
conformance with the construction plans and they do appear to provide sufficient positive drainage
and capacity.
ItemVII.A.1, & VII.A.2 - Conditions of the sub-drains serving the rain garden were not provided.
Item XV – The During Construction Inspection Checklist for Low Impact Development (LID) is
attached, but no pictures were provided.
If you have any questions or comments, please call me at (970) 833-1406. Thank you for your
consideration.
Country Club Corners Sixth Filing, Lot 1 &2 – Overall Site and Drainage Certifications
October 30, 2018
Page 3 of 3
Sincerely,
Logan Johnson, E.I.T.
Enclosure
cc: Mr. Jim Houck, C-Three LLC
T
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FIREHOUSE CAR WASH AS-BUILT EXHIBIT
LOT 1, COUNTRY CLUB CORNERS 6TH FILING, 126 BRISTLECONE DRIVE, CITY OF FORT COLLINS, COUNTY OF LARIMER,
STATE OF COLORADO
4025 Automation Way, Suite C4
Fort Collins, CO 80525
970-232-9645
www.WashburnSurveying.com
Sheet 1 of 1 Project #: 2017-0041 Date: Jan. 10, 2018 Scale: 1"=20' Drawn: CDB
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ELEVATIONS SHOWN ARE FROM AN AS-BUILT SURVEY OF THE SITE
PERFORMED ON JANUARY 9 AND AUGUST 15, 2018
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CALL BEFORE YOU DIG
CALL UTILITY NOTIFICATION
CENTER OF COLORADO
1-800-922-1987
or 8-1-1
CALL 2-BUSINESS DAYS IN ADVANCE
BEFORE YOU DIG, GRADE OR EXCAVATE FOR THE
MARKING OF UNDERGROUND MEMBER UTILITIES.
CHECKED BY:
Date
City of Fort Collins, Colorado
UTILITY PLAN APPROVAL
Parks and Recreation
Traffic Engineer
Stormwater Utility
Water & Wastewater Utility
City Engineer
CHECKED BY:
APPROVED:
Environmental Planner
CHECKED BY:
CHECKED BY:
CHECKED BY:
CHECKED BY:
Date
Date
Date
Date
Date
Date
RECORD DRAWING
THIS RECORD DRAWING HAS BEEN PREPARED, IN PART, BASED UPON
INFORMATION FURNISHED BY OTHERS. WHILE THIS INFORMATION IS
BELIEVED TO BE RELIABLE, INTERWEST CONSULTING GROUP AND
THE CERTIFYING ENGINEER ASSUMES NO RESPONSIBILITY FOR THE
ACCURACY OF THIS RECORD DRAWING DUE TO ANY ERRORS OR
OMISSIONS THAT MAY HAVE BEEN INCORPORATED INTO IT AS A
RESULT OF INCORRECT INFORMATION PROVIDED TO INTERWEST
CONSULTING GROUP AND THE CERTIFYING ENGINEER. THOSE
RELYING ON THIS RECORD DOCUMENT ARE ADVISED TO OBTAIN
INDEPENDENT VERIFICATION OF ITS ACCURACY.
DATE:
DENOTES RECORDED DATA PER
10/30/2018
WASHBURN LAND SURVEYING
NOTES:
1.PIPE LENGTHS ARE GIVEN FROM CENTER OF STRUCTURE TO
CENTER OF STRUCTURE.
2.MANHOLE RIM ELEVATIONS ARE APPROXIMATE. CONFIRM
FINAL ELEVATIONS PRIOR TO INSTALLATION.
3.RCP SHALL HAVE FLEXIBLE GASKET MATERIAL (WATER TIGHT
RUBBER GASKETS) CONFORMING TO ASTM C443 AND TYPE
4-G BELL SPIGOT JOINTS.
4.ALL STORM DRAIN PRIVATELY OWNED AND MAINTAINED.
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HORIZ. SCALE: 1"=20'
VERT. SCALE: 1"=2'
4975
4980
4985
4975
4980
4985
9+7510+0010+5011+0011+5012+0012+5013+0013+50
SD-03 PROFILE
HORIZ. SCALE: 1"=20'
VERT. SCALE: 1"=2'
4975
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4985
4975
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SCALE: 1" =
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SCALE: 1" =2'
CALL BEFORE YOU DIG
CALL UTILITY NOTIFICATION
CENTER OF COLORADO
1-800-922-1987
or 8-1-1
CALL 2-BUSINESS DAYS IN ADVANCE
BEFORE YOU DIG, GRADE OR EXCAVATE FOR THE
MARKING OF UNDERGROUND MEMBER UTILITIES.
CHECKED BY:
Date
City of Fort Collins, Colorado
UTILITY PLAN APPROVAL
Parks and Recreation
Traffic Engineer
Stormwater Utility
Water & Wastewater Utility
City Engineer
CHECKED BY:
APPROVED:
Environmental Planner
CHECKED BY:
CHECKED BY:
CHECKED BY:
CHECKED BY:
Date
Date
Date
Date
Date
Date
RECORD DRAWING
THIS RECORD DRAWING HAS BEEN PREPARED, IN PART, BASED UPON
INFORMATION FURNISHED BY OTHERS. WHILE THIS INFORMATION IS
BELIEVED TO BE RELIABLE, INTERWEST CONSULTING GROUP AND
THE CERTIFYING ENGINEER ASSUMES NO RESPONSIBILITY FOR THE
ACCURACY OF THIS RECORD DRAWING DUE TO ANY ERRORS OR
OMISSIONS THAT MAY HAVE BEEN INCORPORATED INTO IT AS A
RESULT OF INCORRECT INFORMATION PROVIDED TO INTERWEST
CONSULTING GROUP AND THE CERTIFYING ENGINEER. THOSE
RELYING ON THIS RECORD DOCUMENT ARE ADVISED TO OBTAIN
INDEPENDENT VERIFICATION OF ITS ACCURACY.
DATE:
DENOTES RECORDED DATA PER
10/30/2018
WASHBURN LAND SURVEYING
NOTES:
1.PIPE LENGTHS ARE GIVEN FROM CENTER OF STRUCTURE TO
CENTER OF STRUCTURE.
2.MANHOLE RIM ELEVATIONS ARE APPROXIMATE. CONFIRM
FINAL ELEVATIONS PRIOR TO INSTALLATION.
3.RCP SHALL HAVE FLEXIBLE GASKET MATERIAL (WATER TIGHT
RUBBER GASKETS) CONFORMING TO ASTM C443 AND TYPE
4-G BELL SPIGOT JOINTS.
4.ALL STORM DRAIN PRIVATELY OWNED AND MAINTAINED.
Country Club Corners Sixth Filing
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
Stage Storage
Volume (pond volume calculated using the prismoidal formula):
Original
CONTOUR (FT)AREA (FT2)AREA (ACRE)VOLUME
(ACRE-FT)DEPTH (FT)CUMULATIVE VOLUME
(ACRE-FT)CONTOUR (FT)AREA (FT2)AREA (ACRE)VOLUME
(ACRE-FT)DEPTH (FT)
CUMULATIVE
VOLUME
(ACRE-FT)
4973.19 0 0.000 0.000 0.00 0.000 4973.15 0 0.000 0.000 0.00 0.000
4973.50 1431.35 0.033 0.003 0.31 0.003 4974.0 3641.1707 0.084 0.024 0.85 0.024
4974.00 4634.93 0.106 0.033 0.81 0.036 4975.0 15055.09 0.346 0.200 1.85 0.223
4974.50 9732.86 0.223 0.081 1.31 0.117 4976.0 29282.61 0.672 0.500 2.85 0.723
4975.00 15866.89 0.364 0.145 1.81 0.263 4977.0 34156.5675 0.784 0.727 3.85 1.451
4975.50 22039.27 0.506 0.217 2.31 0.479 4978.0 37138.2236 0.853 0.818 4.85 2.269
4976.00 27546.75 0.632 0.284 2.81 0.763
4976.50 30722.82 0.705 0.334 3.31 1.097
4977.00 33135.55 0.761 0.366 3.81 1.464
4977.50 34718.55 0.797 0.389 4.31 1.853
4978.00 36331.64 0.834 0.408 4.81 2.261
4978.1 36659.61 0.842 0.084 4.91 2.345
0.00 N/A ft 0.00 N/A ft
2.27 4978.01 ft 2.27 4978.00 ft
Water Quality Asbuilt Volume
0.00 Elev interpolate to volume of N/A acre-ft
100-yr Asbuilt Volume
N/A Elev interpolate to volume of N/A acre-ft
Design Asbuilt Difference
Top of Berm Elev 4978.00 4978.10 0.1 ft
Spillway Elev N/A N/A N/A ft
Pond Bottom 4973.15 4973.19 0.04 ft
Top of Outlet Structure 4973.15 4973.19 0.04 ft
WQCV N/A N/A N/A acre-ft
Pond Volume 2.27 2.35 0.076 acre-ft
Contour Areas Design Asbuilt Difference
4900 0.00 0.00 0 ft2
4900 0.00 0.00 0 ft2
4900 0.00 0.00 0 ft2
4900 0.00 0.00 0 ft2
4900 0.00 0.00 0 ft2
Required 100-yr Detention Volume (including WQCV) =
Acre-Ft Interpolates to an Elev. of
Required Water Quality Capture Volume =
Acre-Ft Interpolates to an Elev. of
Required 100-yr Detention Volume (including WQCV) =
Acre-Ft Interpolates to an Elev. of
J.Claeys
Interwest Consulting Group
1303-158-00
July 6, 2018
Required Water Quality Capture Volume =
Acre-Ft Interpolates to an Elev. of
4972.00
4973.00
4974.00
4975.00
4976.00
4977.00
4978.00
4979.00
0.0 0.5 1.0 1.5 2.0 2.5
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DETENTION POND VOLUME (AC-FT)
DETENTION POND VOLUME
VERSUS ELEVATION
()
3
2121 DepthAAAA
V
++
=
2
12
1
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12
2 x
yy
yyx
yy
yyx
−
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−=
1303-158-00 PondCalcs_As-Built.xls - Pond Stage Storage (Asbuilt)Page 1 of 1
Stormwater Facility Name:
Facility Location & Jurisdiction:
User (Input) Watershed Characteristics User Defined User Defined User Defined User Defined
Watershed Slope =0.005 ft/ft Stage [ft] Area [ft^2] Stage [ft] Discharge [cfs]
Watershed Length-to-Width Ratio = 2.00 L:W 0.00 0 0.00 0.00
Watershed Area = 11.69 acres 0.31 1,431 0.81 2.15
Watershed Imperviousness = 90.0% percent 0.81 4,635 1.81 4.31
Percentage Hydrologic Soil Group A = 0.0%percent 1.31 9,733 2.81 5.70 40
Percentage Hydrologic Soil Group B = 0.0% percent 1.81 15,867 3.81 6.82
Percentage Hydrologic Soil Groups C/D = 100.0% percent 2.31 22,039 4.91 7.78
2.81 27,547 5.31 7.78
3.31 30,723
3.81 33,136
4.31 34,719
User Input: Detention Basin Characteristics 4.81 36,332
WQCV Design Drain Time = 1.00 hours 4.91 36,660
5.31 37,118
After completing and printing this worksheet to a pdf, go to:
https://maperture.digitaldataservices.com/gvh/?viewer=cswdif,
create a new stormwater facility, and
attach the pdf of this worksheet to that record.
Routed Hydrograph Results
Design Storm Return Period =WQCV 2 Year 5 Year 10 Year 25 Year 50 Year 100 Year
Two-Hour Rainfall Depth =0.53 0.98 1.36 1.71 2.31 2.91 3.67 in
Calculated Runoff Volume =0.196 0.858 1.224 1.577 2.193 2.810 3.612 acre-ft
OPTIONAL Override Runoff Volume =acre-ft
Inflow Hydrograph Volume =0.195 0.857 1.224 1.576 2.192 2.810 3.612 acre-ft
Time to Drain 97% of Inflow Volume =2 3 4 4 5 6 7 hours
Time to Drain 99% of Inflow Volume =2 3 4 4 5 6 7 hours
Maximum Ponding Depth =0.86 2.18 2.67 3.10 3.78 4.43 5.26 ft
Maximum Ponded Area =0.118 0.467 0.596 0.673 0.757 0.806 0.851 acres
Maximum Volume Stored =0.045 0.420 0.683 0.956 1.447 1.957 2.644 acre-ft
Stormwater Detention and Infiltration Design Data Sheet
Country Club Corners Sixth Filing
Fort Collins, CO
Workbook Protected Worksheet Protected
1303-158-00 Drain Time.xlsm, Design Data 7/6/2018, 12:06 PM
Doing_Clear_Formatting =Yes
CountA=1
0 1 2 3
#N/A
#N/A
0 1 2 3
#N/A
#N/A
Check Data Set 1 Check Data Set 1
Stormwater Detention and Infiltration Design Data Sheet
Area
Discharge
0
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30
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60
70
0.1 1 10
FL
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TIME [hr]
100YR IN
100YR OUT
50YR IN
50YR OUT
25YR IN
25YR OUT
10YR IN
10YR OUT
5YR IN
5YR OUT
2YR IN
2YR OUT
WQCV IN
WQCV OUT
0
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50YR
25YR
10YR
5YR
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WQCV
1303-158-00 Drain Time.xlsm, Design Data 7/6/2018, 12:06 PM
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =71.2 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.712
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.22 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area) Area = 35,609 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 =666.0 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 =507 sq ft
D) Actual Flat Surface Area AActual =513 sq ft
E) Area at Design Depth (Top Surface Area)ATop =1126 sq ft
F) Rain Garden Total Volume VT=820 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 =2.0 ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =666 cu ft
iii) Orifice Diameter, 3/8" Minimum DO =3/5 in
Design Procedure Form: Rain Garden (RG)
L. Johnson
Interwest Consulting Group
July 6, 2018
Country Club Corners Sixth Filing - Lot 1 - As-Built
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
1303-158-00_AS-BUILT - UD-BMP_v3.05.xlsm, RG 7/6/2018, 12:14 PM
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)
L. Johnson
Interwest Consulting Group
July 6, 2018
Country Club Corners Sixth Filing - Lot 1 - As-Built
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
1303-158-00_AS-BUILT - UD-BMP_v3.05.xlsm, RG 7/6/2018, 12:14 PM
2/14/17 Page 1
CERTIFICATION OF LOT GRADING
Pursuant to Fort Collins City Code § 26-544 & City Land Use Code § 3.3.2 (e)
Date:
Address:
Lot: Block:
Subdivision:
Permit Application #:
Larimer County Parcel #:
Larimer County Reception #:
(on development agreement)
I, (print) , a Colorado registered professional engineer, verify that construction
of all stormwater facilities and grading is complete and hereby submit this certification.
Please answer the following questions by initialing the appropriate response. For each question initialed “No,” attach an
explanation detailing how this will affect stormwater drainage for this lot and any adjacent lots.
1.Certification includes attached Stormwater-approved grading plan. (NOTE: City’s
Building Department does not approve grading plans).
2.Certification includes the attached as-built survey dated (must be within 60
days of the date the certification is submitted) accurately and truthfully depicting
elevations for:
Top of foundation/finished floor
Finished grade on each side of the structure
Quarter points along each lot line (not more than 50 feet apart)
Break points/high points
Swales
Berms
Retaining walls
Air conditioning pads
Window wells
Any other appurtenance(s) within an easement
3.All elevations are within a 0.2 foot tolerance of the approved grading plan.
4.The top of foundation is at least 6 inches above the highest grade surrounding the
structure.
5.There is a minimum grade of 5% away from the structure within the first 5 to 10 feet
adjacent to the residence.
6.All slopes meet or exceed the minimum requirement of 2% (1% is acceptable on single
family lots when the swale is draining the runoff from only two adjoining properties)
and are not steeper than 33% (3:1).
7.All flow lines of stormwater drainage swales are a minimum of 6 inches below the
elevation of ground adjacent to the structure and will direct drainage as shown on the
Stormwater-approved grading plan.
8.All downspout locations and discharge directions are shown on the as-built survey.
Runoff is directed into an appropriate drainage system or lot line swale, and it is not
directed onto neighboring properties.
No Yes
No Yes
No Yes
No Yes
No Yes
No Yes
No Yes
No Yes
Country Club Corners, 6th Filing
1606 & 1512 N. College Avenue
Fort Collins, CO 9701275001 & 9701275002
1 & 2 N/A
Jason T. Claeys
08/15/2018
Accepted 11/7/2018 WL
B1702385
2/14/17 Page 2
9.A smooth transition with no vertical offset (step) in grade is provided at the lot line to all
adjacent properties.
10.The grading of this lot does not adversely affect neighboring properties or City
infrastructure.
11.Landscaping has been completed prior to survey. If not, please indicate who will be
responsible for completing landscaping:
12.Final site cleanup has been completed.
13.I personally visited the site as part of the certification process, and in my professional
opinion, the as-built survey is an accurate representation of the site conditions..
No Yes
No Yes
No Yes
No Yes
No Yes
14.Based on this information, I certify that (check one):
□The elevations and drainage patterns of the lot/site are in substantial conformance with the City
approved drainage and grading plan for the property (information attached).
□The elevations and drainage patterns of the lot/site as measured are in general conformance with the
City approved drainage plan with exceptions (information attached). In my professional judgment the
elevations and grading of the lot/site as constructed are functionally adequate and equivalent to the
specifically approved drainage plan, and will affect stormwater drainage on and off the lot/site in a
manner consistent with the approved drainage plan.
Name:
Email:
Phone:
Company:
Address:
NOTE: A complete certification must be submitted at least two weeks prior to a request for a Certificate of Occupancy
for the lot/site, including, but not limited to, drawings of the lot/site showing the approved design and as-built surveyed
elevations of all structures, drainage and grading features, written information/explanation of discrepancies, and other
information necessary to confirm the above certification to:
Email (preferred)
WaterUtilitiesEng@fcgov.com
Mailing Address
Fort Collins Utilities
ATTN: Water Utilities Engineering
281 North College Avenue
Fort Collins, CO 80521
Questions?
970-221-6700
PE Stamp
Sign and date
Jason T. Claeys, PE
jclaeys@interwestgrp.com
(970) 347-8917
Interwest Consulting Group
1218 W. Ash Street, Suite A
Windsor, CO 80550
1218 W. ASH, STE. A, WINDSOR, COLORADO 80550
TEL. 970.674.3300 – FAX 970.674.3303
October 30, 2018
Mr. Wes Lamarque
Fort Collins Utilities
700 Wood Street
Fort Collins, CO 80522
Via email: wlamarque@fcgov.com
Re: Country Club Corners Sixth Filing – Lots 1 and 2
Clarification of Lot Certification Items
Dear Wes,
Please accept this letter in support of items 2 thru 7 of the Certification of Lot Grading for items
noted as not being in conformance with the checklist descriptions. As a result, we offer the
following for your review and approval:
Item 2 – The as-built survey provided by the surveyor is not dated within 60 days. We believe that
these surveys accurately depict the as-built conditions on site.
Item 3 – Elevations are not all within a 0.2 foot tolerance of the approved grading plan. There were
adjustments made in the field that altered various site grading elements. Though these adjustments
were made, positive drainage away from structures appears to have been achieved.
Item 4 – Top of foundation are not all 6” above the highest grade surrounding the structure along
the north face of the main building. Positive drainage appears to be achieved away from the
structure.
Item 6 – All swale slopes along lot lines are not 1% or greater. Slopes outside of the detention
pond that are less than 1% may incur minimal ponding within landscape areas before reaching a
point of positive drainage. The downspouts from building roofs are directly connected to storm
drain pipes and area inlets are also provided in this area.
Item 8 – All downspout locations and discharge direction are not shown on the as-built survey.
However based on a recent site visit, the downspouts appear to have been constructed in an
appropriate manner and generally within the correct locations based on the construction plans. All
downspouts are directly connected to the storm drainage system. Runoff is directed into an
appropriate drainage system or lot line swale, and it is not directed onto neighboring properties.
This letter is intended to supplement the Certification of Lot Grading and supports our belief that
the grading for the referenced project provides positive drainage away from structures. Therefore,
we request that the lots listed above be deemed acceptable to the City of Fort Collins.
Country Club Corners Sixth Filing, Lot 1 &2 – Lot Certifications
October 30, 2018
Page 2 of 2
If you have any questions or comments, please call me at (970) 833-1406. Thank you for your
consideration.
Sincerely,
Logan Johnson, E.I.T.
Enclosure
cc: Mr. Jim Houck, C-Three LLC
T
ME
C
H
FIREHOUSE CAR WASH AS-BUILT EXHIBIT
LOT 1, COUNTRY CLUB CORNERS 6TH FILING, 126 BRISTLECONE DRIVE, CITY OF FORT COLLINS, COUNTY OF LARIMER,
STATE OF COLORADO
4025 Automation Way, Suite C4
Fort Collins, CO 80525
970-232-9645
www.WashburnSurveying.com
Sheet 1 of 1 Project #: 2017-0041 Date: Jan. 10, 2018 Scale: 1"=20' Drawn: CDB
Sc
a
l
e
:
1
"
=
2
0
'
ELEVATIONS SHOWN ARE FROM AN AS-BUILT SURVEY OF THE SITE
PERFORMED ON JANUARY 9 AND AUGUST 15, 2018