HomeMy WebLinkAboutSite Certifications - 11/10/2017/15 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
Raw Urth
6/15/17
Yes
Yes
Yes
Yes
Yes
Yes
/15 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.
Yes
N/A
Yes
N/A
N/A
N/A
Yes
Yes
Yes
Yes
Yes
Yes
Yes
/15 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.)
Yes
N/A
N/A
N/A
N/A
Yes
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
/15 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
Yes
Yes
Yes
Yes
N/A
N/A
Yes
Yes
Yes
Yes
Yes
Yes
/15 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 inlet covers are stenciled or stamped with the following 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
Yes
Yes
Yes
N/A
N/A
N/A
N/A
N/A
N/A
Yes
Yes
Yes
/15 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.
Yes
N/A
Yes
N/A
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
N/A
N/A
/15 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
N/A
Yes
N/A
N/A
Yes
Yes
Yes
Yes
/15 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: WĂƚƌŝĐĂŝ<ƌŽĞƚĐŚ
Email: ƚƌŝĐŝĂΛŶŽƌƚŚƐƚĂƌĚĞƐŝŐŶŝŶĐ͘ĐŽŵ
Phone: ϵϳϬͲϲϴϲͲϲϵϯϵ
Company: EŽƌƚŚ^ƚĂƌĞƐŝŐŶ͕/ŶĐ͘
Address: ϳϬϬƵƚŽŵĂƚŝŽŶƌŝǀĞ͕hŶŝƚ/
tŝŶĚƐŽƌ͕KϴϬϱϱϬ
PE Stamp
Sign and date
6/19/17
August 10, 2017
Dan Mogen
City of Fort Collins
700 Wood Street
Fort Collins, CO
Re: Raw Urth Drainage Certification & Record Drawing
Mr. Mogen
This letter and attached documents are to serve as an overall site certification for Raw
Urth (Lot 20, Block 3 of Evergreen Park). All information provided in this letter and on
the record drawing plans you have received is based on a field survey completed by King
Surveying dated May 19, 2017.
The pond was constructed with sufficient volume (0.196 acre feet) when compared to the
design (0.200 acre feet). The pond provides adequate volume at elevation 4771.83 prior
to overtopping at the spillway on the south. An as constructed stage storage table is
attached.
During construction, a discrepancy was discovered between the drainage plan and the
building permit drawings. The drainage plan was approved with the roof sloping to the
south and drainage directly into the detention pond but the building permit drawings
showed it sloping to the north. Ther was not adequate capacity in the swale on the north,
inlet or pipe to accommodate the roof runoff so the only solution we could see was to
pipe it to the approved location – directly into the pond. A separate pipe was added along
the north side of the building sloping east and then south into the pond. Calculations for
the capacity of this pipe are included at the end of this letter.
The LID swale on the north side of the building was constructed at the elevations per the
design plans. All storm on site is private and was not inspected. The permeable pavers
700 Automation Drive, Unit I
Windsor, CO 80550
Phone: 970-686-6939
Fax: 970-686-1188
were installed on site and photos of the installation process are provided at the end of this
letter.
The swale in the northeast corner of the site was eliminated because of the location and
elevation of the electrical transformer. Upon review it was determined that no impervious
area was draining to this swale and the swale was not included in the LID calculations per
the summary table below.
The finished floor of the buildings were constructed at or within 0.10’ of the design
elevation and all curb and gutter (private) on site were constructed within acceptable
construction tolerances. There appears to be (based on the field survey) sufficient slope
away from the buildings to allow runoff to adequately flow in the direction as intended
by the original design plans.
The final deviation from the approved plans was the change of the storage area from
asphalt to recycled asphalt. The intent is that the storage area will be paved in the future
as funds are available. The applicable utility plan sheets have been revised to reflect this
area as ‘outdoor storage’ without indicating the surface material.
If you have and questions or need additional information for this certification, please call
me.
Sincerely,
Patricia Kroetch, P.E.
ASBUILT STAGE - STORAGE TABLE
(100-YEAR)
LOCATION: Raw Urth Designs
PROJECT NO: 177-09
COMPUTATIONS BY: PPK
SUBMITTED BY: North Star Design, Inc.
DATE: 6/19/2017
100 yr Detention Volume Required = 0.200
Water Quality Volume Required = 0.000
Total Volume Required= 0.200
DESIGN VOLUM
Surface Incremental Total
Stage Area Storage Storage
(ft)(ft2)(ac-ft) (ac-ft)
4768.80 0
4769.0 761 0.001 0.001
4770.0 1,695 0.027 0.029
4771.0 4,321 0.067 0.095
100 yr WSEL 4771.80 7,253 0.104 0.200 <==SPILLWAY ELE
4772.0 8,009 0.139 0.235
4772.3 9,337 0.060 0.294
AS CONSTRUCTED VOLUME
Surface Incremental Total
Stage Area Storage Storage
(ft)(ft2)(ac-ft) (ac-ft)
4768.83 0
4769.0 705 0.001 0.001
4770.0 1,830 0.028 0.029
4771.0 3,645 0.059 0.088
100 yr WSEL 4771.83 7,247 0.108 0.196 <==SPILLWAY ELE
4772.0 7,720 0.128 0.215
4772.3 9,337 0.068 0.284
System Input Summary
Rainfall Parameters
Rainfall Return Period: 100
Rainfall Calculation Method: Formula
One Hour Depth (in): 4.87
Rainfall Constant "A": 28.5
Rainfall Constant "B": 10
Rainfall Constant "C": 0.786
Rational Method Constraints
Minimum Urban Runoff Coeff.: 0.20
Maximum Rural Overland Len. (ft): 500
Maximum Urban Overland Len. (ft): 300
Used UDFCD Tc. Maximum: Yes
Sizer Constraints
Minimum Sewer Size (in): 6.00
Maximum Depth to Rise Ratio: 0.90
Maximum Flow Velocity (fps): 18.0
Minimum Flow Velocity (fps): 2.0
Backwater Calculations:
Tailwater Elevation (ft): 71.80
Manhole Input Summary:
Given Flow Sub Basin Information
Element
Name
Ground
Elevatio
n
(ft)
Total
Know
n
Flow
(cfs)
Local
Contributio
n
(cfs)
Drainag
e
Area
(Ac.)
Runoff
Coefficien
t
5yr
Coefficien
t
Overlan
d
Length
(ft)
Overlan
d
Slope
(%)
Gutter
Lengt
h
(ft)
Gutter
Velocit
y
(fps)
OUTFAL
L 1 73.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Section 3 73.50 2.10 0.70 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Section 2 73.50 1.40 0.70 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Section 1 73.50 0.70 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Manhole Output Summary:
Local Contribution Total Design Flow
Element
Name
Overland
Time
(min)
Gutter
Time
(min)
Basin Tc
(min)
Intensity
(in/hr)
Local
Contrib
(cfs)
Coeff.
Area
Intensity
(in/hr)
Manhole Tc
(min)
Peak
Flow
(cfs)
Comment
OUTFALL 1 0.00 0.00 0.00 0.00 0.00 0.10 21.82 0.53 2.10
Section 3 0.00 0.00 0.00 0.00 0.70 0.00 0.00 0.00 2.10
Section 2 0.00 0.00 0.00 0.00 0.70 0.00 0.00 0.00 1.40
Section 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.70
Sewer Input Summary:
Elevation Loss Coefficients Given Dimensions
Element
Name
Sewer
Length
(ft)
Downstream
Invert
(ft)
Slope
(%)
Upstream
Invert
(ft)
Mannings
n
Bend
Loss
Lateral
Loss
Cross
Section
Rise
(ft or in)
Span
(ft or in)
Section 3 84.80 69.50 0.6 70.01 0.015 0.03 0.00 CIRCULAR 10.00 in 10.00 in
Section 2 125.00 70.01 0.6 70.76 0.015 0.05 0.00 CIRCULAR 8.00 in 8.00 in
Section 1 73.00 70.76 0.6 71.20 0.015 0.05 0.00 CIRCULAR 8.00 in 8.00 in
Sewer Flow Summary:
Full Flow Capacity Critical Flow Normal Flow
Element
Name
Flow
(cfs)
Velocity
(fps)
Depth
(in)
Velocity
(fps)
Depth
(in)
Velocity
(fps)
Froude
Number
Flow
Condition
Flow
(cfs)
Surcharged
Length
(ft)
Comment
Section 3 2.40 3.05 7.43 4.11 8.70 3.44 0.73 Pressurized 2.10 84.80
Section 2 1.47 2.70 6.35 3.83 7.77 3.08 0.67 Pressurized 1.40 125.00
Section 1 0.81 2.33 4.74 3.25 5.72 2.62 0.69 Pressurized 0.70 73.00
A Froude number of 0 indicates that pressured flow occurs (adverse slope or undersized pipe).
If the sewer is not pressurized, full flow represents the maximum gravity flow in the sewer.
If the sewer is pressurized, full flow represents the pressurized flow conditions.
Sewer Sizing Summary:
Existing Calculated Used
Element
Name
Peak
Flow
(cfs)
Cross
Section Rise Span Rise Span Rise Span Area
(ft^2) Comment
Section 3 2.10 CIRCULAR 10.00 in 10.00 in 12.00 in 12.00 in 10.00 in 10.00 in 0.79
Section 2 1.40 CIRCULAR 8.00 in 8.00 in 10.00 in 10.00 in 8.00 in 8.00 in 0.55
Existing height is smaller
than the suggested height.
Existing width is smaller
than the suggested width.
Section 1 0.70 CIRCULAR 8.00 in 8.00 in 9.00 in 9.00 in 8.00 in 8.00 in 0.35
Existing height is smaller
than the suggested height.
Existing width is smaller
than the suggested width.
Calculated diameter was determined by sewer hydraulic capacity rounded up to the nearest
commercially available size.
Sewer sizes should not decrease downstream.
All hydraulics where calculated using the 'Used' parameters.
Grade Line Summary:
Tailwater Elevation (ft): 71.80
Invert Elev.
Downstream
Manhole
Losses
HGL EGL
Element
Name
Downstream
(ft)
Upstream
(ft)
Bend
Loss
(ft)
Lateral
Loss
(ft)
Downstream
(ft)
Upstream
(ft)
Downstream
(ft)
Friction
Loss
(ft)
Upstream
(ft)
Section
3 69.50 70.01 0.00 0.00 71.80 72.19 71.91 0.39 72.30
Section
2 70.01 70.76 0.01 0.00 72.20 72.88 72.31 0.68 72.98
Section
1 70.76 71.20 0.00 0.00 72.92 73.25 72.99 0.32 73.31
Bend and Lateral losses only apply when there is an outgoing sewer. The system outfall, sewer #0,
is not considered a sewer.
Bend loss = Bend K * V_fi ^ 2/(2*g)
Lateral loss = V_fo ^ 2/(2*g)- Junction Loss K * V_fi ^ 2/(2*g).
Friction loss is always Upstream EGL - Downstream EGL.
0.00 28.30 56.60 84.90 113.20 141.50 169.80 198.10 226.40 254.70
69.10
69.50
69.90
70.30
70.70
71.10
71.50
71.90
72.30
72.70
73.10
HGL
EGL
RAW URTH
LOW IMPACT
DEVELOPMENT (LID) SWALE
CONSTRUCTION PHOTOS
RAW URTH
PERMEABLE PAVER
INSTALLATION
CONSTRUCTION PHOTOS
RAW URTH
RIPRAP INSTALLATION
& SOIL AMENDMENT
CONSTRUCTION PHOTOS
RIPRAP INSTALLATION
SOIL AMENDMENT
SOIL AMENDMENT
RAW URTH
POST‐CONSTRUCTION
SITE PHOTOS