HomeMy WebLinkAboutLot Certifications - 07/24/20175/26/16 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:
z Top of foundation/finished floor
z Finished grade on each side of the structure
z Quarter points along each lot line (not more than 50 feet apart)
z Break points/high points
z Swales
z Berms
z Retaining walls
z Air conditioning pads
z Window wells
z 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 25% (4:1).
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
DW
See attached photos for additional information
Lot elevations did not change except
along south side of drive. New elevations
shown, where applicable.
N/A
N/A
N/A
Grading plan was revised in coordination with City Stormwater Department (***See note)
***See note below
***Building was constructed with FFE 2.44' lower than per design plan. As a result, concrete pan was
reconstructed at 0.45% slope to west side of house. Slope away along west is 3.33%, others >5%
Gutters and downspouts not installed at time of survey
***See note below. Flowline is 4" below elevation adjacent to structure along west side but directs drainage properly
Concrete pans are constructed at 0.45% slope
As-built survey is greater than 60 days, however, site has not changed.
Delay in submittal was due to compiling lot certification documents.
DW
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07/24/17 Stead
249 S Taft Hill Rd B1600348
Fort Collins, CO 80522 97094-16-002
2 20160010451
Daniel J Weber
05/01/17
5/26/16 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):
Ƒ 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).
Ƒ 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
7/24/17
DW
DW
DW
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Homeowner
✔
Daniel J. Weber
danny@northernengineering.com
(970) 568-5418
Northern Engineering
301 N Howes St, Ste 100
Fort Collins, CO 80521
301 N. Howes Street, Suite 100, Fort Collins, CO 80521 970.221.4158 www.northernengineering.com
July 24, 2017
Dan Mogen, EI
Fort Collins Stormwater Utility
700 Wood Street
Fort Collins, CO 80521
RE: Overall Site and Lot Certification Supplemental Information
(Stead Subdivision)
Dear Mr. Mogen:
I have visited the site referred to above and offer this supplemental information to the drainage
certifications for the Stead Subdivision.
Northern Engineering was not onsite during the construction of the facilities for the Stead
Subdivision. Through our initial asbuilt survey, it was determined that the building’s Finished Floor
Elevation (FFE) was 2.44’ lower than plan elevation. Additionally, the original concrete pan had
several low points and a flowline elevation that was at or above the building’s constructed FFE.
Working with City Stormwater Staff, the proposed resolution was to reconstruct the concrete pan at
a 0.45% slope from Taft Hill Road and around the building. This dropped the overall concrete pan
elevation by almost 12” adjacent to the foundation, demonstrating an acceptable 6” difference
between FFE and Finished Grade (FG). Furthermore, providing slope away from the structure and
into the reconstructed concrete pan where stormwater can be transported to Taft Hill in accordance
with the approved construction documents.
This drainage certification verifies the capacity of the swales outlined in the Stead Final Drainage
Report. The total runoff for swale Section A-A was recalculated as 0.64 cfs based upon asbuilt
conditions. Conservatively, 1.0 cfs was used in the analysis of the swale. Swale Section B-B was
calculated using the total basin runoff, which is similar to the Final Drainage Report.
Thank you and please let me know if you have any questions or concerns.
Sincerely,
NORTHERN ENGINEERING SERVICES, INC.
Danny Weber, P.E.
Project Engineer
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.)
x Use “Yes” for items completed as described.
x Use “N/A” for items that are not applicable to the site being certified.
x 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
Stead
07/24/17
B1600348
N/A
N/A
N/A
N/A
N/A
N/A
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.
x 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.
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
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.)
***Note 1: Capacity of Section A-A reanalyzed based on total flow from asbuilt drainage basin
Note 2: Grading plan was revised with City Staff due to building FFE
Note 3: Analysis for both Sections A-A and B-B are provided with this certification
***See note 1 below
***See note 2 below
***See note 3 below
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
No
N/A
Yes
No
N/A
No
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.
***See note 1 below
***Note 1: Concrete pans were redesigned in coordination with City Staff due to constructed building FFE
Note 2: Some areas have steeper than 8.33% side slope, however, does not effect overall swale capacity.
***See note 1 below
***See note 2 below
See attached letter from contractor
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
No
No
No
No
Yes
Yes
/1Page 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.
ϭ͘The 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.
Ϯ͘The size of the inlet opening is consistent with the approved detail. (Check height and width.)
ϯ͘The 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.
ϰ͘The 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.
ϱ͘The as-built size of the inlet box is as shown on the construction plans or an explanation or
justification is attached.
ϲ͘All dLJƉĞ͕Z͕ϭϯĂŶĚϭϲinlet covers are stenciled or stamped with the following;ŽƌĂŶ
ĞƋƵŝǀĂůĞŶƚͿĚĞƐŝŐŶĂƚŝŽŶ͗ NO DUMPING – DRAINSTO 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.
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
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
N/A
N/A
N/A
Yes
Yes
Yes
Yes
Yes
Yes
N/A
N/A
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
N/A
N/A
N/A
N/A
N/A
N/A
Yes
Yes
Yes
N/A
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
Sign and date
7/24/17
Daniel J Weber
danny@northernengineering.com
(970) 568-5418
Northern Engineering
301 N Howes St, Ste 100
Fort Collins, CO 80521
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74.08
74.26
74.93
74.5
8
74.8
6 74.6
9
0.5%
1' SIDEWALK CHASE
74.4
2
2.0%
76.0
5
5.0
%
APPROXIMATE LOCATION
OF CONCRETE PAN
NEW
RESIDENCE
FFE=5079.25
ASBUILT
FFE=5076.81
0.5%
0.
4
%
0.6%
APPROXIMATE LOCATION
OF CONCRETE PAN
GARAGE NOT CONSTRUCTED
BARN NOT CONSTRUCTED
1
ASBUILT LOCATION
1' SIDEWALK CHASE
0.5%
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CALL UTILITY NOTIFICATION CENTER OF
COLORADO
Know what's below.
before you dig.Call
R
NORTH
LEGEND:
5013
PROPOSED CONTOUR 93
EXISTING CONTOUR
PROPOSED SPOT ELEVATION 33.43
PROPOSED SLOPES
1.THE SIZE, TYPE AND LOCATION OF ALL KNOWN UNDERGROUND UTILITIES ARE
APPROXIMATE WHEN SHOWN ON THESE DRAWINGS. IT SHALL BE THE RESPONSIBILITY
OF THE CONTRACTOR TO VERIFY THE EXISTENCE OF ALL UNDERGROUND UTILITIES IN
THE AREA OF THE WORK. BEFORE COMMENCING NEW CONSTRUCTION, THE
CONTRACTOR SHALL BE RESPONSIBLE FOR LOCATING ALL UNDERGROUND UTILITIES
AND SHALL BE RESPONSIBLE FOR FOR ALL UNKNOWN UNDERGROUND UTILITIES.
2.REFER TO THE PLAT FOR LOT AREAS, TRACT SIZES, EASEMENTS, LOT DIMENSIONS,
UTILITY EASEMENTS, OTHER EASEMENTS, AND OTHER SURVEY INFORMATION.
3.ALL PROJECT ELEVATIONS ARE ON THE VERTICAL DATUM NAVD 88. SEE COVER SHEET
FOR BENCHMARK REFERENCES.
4.ALL CURB SPOTS ARE FLOWLINE ELEVATIONS. ALL OTHER SPOTS ARE FINISHED
GRADE ELEVATIONS.
GENERAL NOTES:
2.0%
(47.45
)
EXISTING SPOT ELEVATION
EXISTING LOT LINE
EASEMENT LINE
20 20
20
40 60
NOTE:
ALL BMP'S SHOWN ON THIS PLAN ARE GRAPHIC
REPRESENTATIONS ONLY. FINAL DETERMINATION OF SIZE
AND LOCATION SHALL BE DETERMINED BY THE CONTRACTOR.
TEMPORARY BMP'S
SF
EROSION CONTROL NOTES:
TABLE OF CONSTRUCTION SEQUENCE AND BMP
APPLICATION
CONSTRUCTION PHASE
(DESCRIPTION)
PHASE I
(GRADING)
PHASE II
(INFRASTRUCTURE)
PHASE III
(VERTICAL
CONSTRUCITON)
PHASE IV
(PERMANENT
BMP'S)
Grading (Include Offsite)
Overlot
Pipeline Installation
Stormwater
Concrete Installation
Site Walls
Building Structure
Miscellaneous
Hardscape Amenities
BEST MANAGEMENT PRACTICES
Temporary
Inlet Protection (IP)
Vehicle Tracking Control (VTC)
Flow Barriers (Wattles, Rock Socks, etc.) (WD)
Concrete Washout Area (CWA)
Preventative Maintenance Activities/Meetings/etc.
Silt Fence (SF)
Permanent
Mulching/Sealant
Permanent Seed Planting
Sewer Service
Water Service
Curb and Gutter
RECORD DRAWING
1
RE
C
O
R
D
D
R
A
W
I
N
G
S
DJ
W
05
/
0
1
/
1
7
Concrete pan along the south looking northwest near entry doors
Concrete pan along the south looking east
Foundation exposure along the south
Concrete pan along the east looking north
Foundation exposure along east side
Concrete pan along the north looking west
Concrete pan along the north looking east
Concrete pan connection at west end of driveway
Concrete pan along south side of driveway looking east
Concrete pan along south side of driveway looking east
Concrete pan along south side of driveway near Taft Hill Rd
1’ sidewalk chase at Taft Hill Rd
CHARACTER OF SURFACE: Runoff
Coefficient
Percentage
Impervious Project:Stead
Streets, Parking Lots, Roofs, Alleys, and Drives:Calculations By:D. Weber
Asphalt ……....……………...……….....…...……………….…………………………………..0.95 100 Date:
Concrete …….......……………….….……….………………..….…………………………………0.95 90
Gravel ……….…………………….….…………………………..………………………………..0.50 40
Roofs …….…….………………..……………….…………………………………………….. 0.95 90
Concrete Pavers…………………………...………………..……………………………………………..0.40 22
Lawns and Landscaping
Sandy Soil ……..……………..……………….……………………………………………..0.15 0
Clayey Soil ….….………….…….…………..……………………………………………….0.25 0 2-year Cf = 1.00 100-year Cf = 1.25
Basin ID Basin Area
(s.f.)
Basin Area
(ac)
Area of
Asphalt
(ac)
Area of
Concrete
(ac)
Area of
Roofs
(ac)
Area of
Gravel
(ac)
Area of
Concrete
Pavers
(ac)
Area of
Lawns and
Landscaping
(ac)
2-year
Composite
Runoff
Coefficient
10-year
Composite
Runoff
Coefficient
100-year
Composite
Runoff
Coefficient
Composite
% Imperv.
Section A-A 3,979 0.09 0.00 0.01 0.03 0.02 0.00 0.04 0.56 0.56 0.70 41.5
DEVELOPED COMPOSITE % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS
Runoff Coefficients are taken from the City of Fort Collins Storm Drainage Design Criteria and Construction Standards, Table 3-3. % Impervious taken from UDFCD USDCM, Volume I.
10-year Cf = 1.00
May 2, 2017
D:\Projects\1130-001\Drainage\Hydrology\1130-001_Rational-Calcs_SectionA-A.xlsx\C-Values
Overland Flow, Time of Concentration:The Stead
Project:Stead
42228.0 Calculations By:
Date:
Gutter/Swale Flow, Time of Concentration:
Tt = L / 60V
Tc = Ti + Tt (Equation RO-2)
Velocity (Gutter Flow), V = 20·S½
Velocity (Swale Flow), V = 15·S½
NOTE: C-value for overland flows over grassy surfaces; C = 0.25
Is Length
>500' ?
C*Cf
(2-yr
Cf=1.00)
C*Cf
(10-yr
Cf=1.00)
C*Cf
(100-yr
Cf=1.25)
Length,
L
(ft)
Slope,
S
(%)
Ti
2-yr
(min)
Ti
10-yr
(min)
Ti
100-yr
(min)
Length,
L
(ft)
Slope,
S
(%)
Velocity,
V
(ft/s)
Tt
(min)
Length,
L
(ft)
Slope,
S
(%)
Velocity,
V
(ft/s)
Tt
(min)
2-yr
Tc
(min)
10-yr
Tc
(min)
100-yr
Tc
(min)
Section A-A Section A-A No 0.25 0.25 0.31 10 3.3 3.4 3.4 3.1 0 0.0 0.00 N/A 130 0.5 1.01 2.2 5.5 5.5 5.3
DEVELOPED TIME OF CONCENTRATION COMPUTATIONS
Gutter Flow Swale Flow
Design
Point Basin
Overland Flow
D. Weber
May 2, 2017
Time of Concentration
(Equation RO-4)
()
3
1
*1.187.1
S
LCfCTi
−=
D:\Projects\1130-001\Drainage\Hydrology\1130-001_Rational-Calcs_SectionA-A.xlsx\Tc-2-yr_&_100-yr
DESIGN
POINT
BASIN
ID
TOTAL
AREA
(acres)
C2 C10 C100
2-yr Tc
(min)
10-yr
Tc
(min)
100-yr
Tc
(min)
Q2
(cfs)
Q10
(cfs)
Q100
(cfs)
Section A-A Section A-A 0.09 0.56 0.56 0.70 5.5 5.5 5.3 0.14 0.24 0.64
DEVELOPED RUNOFF SUMMARY TABLE
D:\Projects\1130-001\Drainage\Hydrology\1130-001_Rational-Calcs_SectionA-A.xlsx\Summary Table
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Tuesday, May 2 2017
Section A-A (asbuilt)
User-defined
Invert Elev (ft) = 75.41
Slope (%) = 0.45
N-Value = 0.016
Calculations
Compute by: Known Q
Known Q (cfs) = 1.00
(Sta, El, n)-(Sta, El, n)...
( 0.00, 75.85)-(3.50, 75.45, 0.025)-(4.00, 75.41, 0.013)-(4.50, 75.45, 0.013)-(10.00, 75.65, 0.013)
Highlighted
Depth (ft) = 0.22
Q (cfs) = 1.000
Area (sqft) = 0.79
Velocity (ft/s) = 1.27
Wetted Perim (ft) = 7.54
Crit Depth, Yc (ft) = 0.20
Top Width (ft) = 7.53
EGL (ft) = 0.25
-1 0 1 2 3 4 5 6 7 8 9 10 11
Elev (ft)Depth (ft)Section
75.00 -0.41
75.25 -0.16
75.50 0.09
75.75 0.34
76.00 0.59
Sta (ft)
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Tuesday, May 2 2017
Section B-B (asbuilt)
User-defined
Invert Elev (ft) = 74.58
Slope (%) = 0.45
N-Value = 0.024
Calculations
Compute by: Known Q
Known Q (cfs) = 2.03
(Sta, El, n)-(Sta, El, n)...
( 0.00, 75.77)-(6.25, 74.62, 0.025)-(6.75, 74.58, 0.013)-(7.25, 74.98, 0.013)-(12.75, 75.16, 0.025)
Highlighted
Depth (ft) = 0.56
Q (cfs) = 2.030
Area (sqft) = 1.58
Velocity (ft/s) = 1.29
Wetted Perim (ft) = 8.91
Crit Depth, Yc (ft) = 0.46
Top Width (ft) = 8.71
EGL (ft) = 0.59
-2 0 2 4 6 8 10 12 14 16
Elev (ft)Depth (ft)Section
74.00 -0.58
74.50 -0.08
75.00 0.42
75.50 0.92
76.00 1.42
Sta (ft)