HomeMy WebLinkAboutINVERNESS INNOVATION PARK - ODP - 30-09 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTPreliminary Drainage, Erosion Control and Water Quality Report
Rocky Mountain Innovation Initiative
IX. APENDICES
Appendix I
■ Hydrology and Pipes
Appendix II
■ Detention
■ Infiltrometer Test Results
Appendix III
• FEMA Firmette
■ Drainage and Erosion Control Plan
Preliminary Drainage, Erosion Control and Water Quality Report
Rocky Mountain Innovation Initiative
VII. CONCLUSIONS
A. Compliance with standards
I. All drainage design will conform to the criteria and requirements of City of
Fort Collins Storm Drainage and Design Criteria and Construction Standards.
2. Proposed sediment/erosion control measures will conform to the
recommendations of City of Fort Collins Storm Drainage and Design Criteria
and Construction Standards and generally accepted erosion control
procedures.
B. Drainage Concept
I. The proposed drainage plan concept for the RM12 project will be effective for
the control of stormwater runoff and water quality for the proposed site.
Vill. REFERENCES
• City of Fort Collins Storm Drainage and Design Criteria and Construction Standards
• Urban Storm Drainage Criteria Manual Volume 1 • Urban Drainage and Flood Control
District, Denver, Colorado, March, 1969.
• Urban Storm Drainage Criteria Manual Volume 2; Urban Drainage and Flood Control
District, Denver, Colorado, March, 1969.
• Urban Storm Drainage Criteria Manual Volume 3 Best Management Practices; Urban
Drainage and Flood Control District, Denver, Colorado, September, 1999.
Preliminary Drainage, Erosion Control and Water Quality Report
Rocky Mountain Innovation Initiative
VI. SEDIMENT/EROSION CONTROL
A. General Concept
I. Temporary erosion control measures will be installed with this project.
These measures will include:
a. Silt fence along the property lines.
b. Inlet filters at all inlets.
c. Water trucks and soil terracing to address construction dust abatement.
d. Vehicle tracking pad at the construction entrance.
e. The detention pond will act as a sediment basin during construction.
2. Permanent sediment\erosion control measures will include riprap forebays at
all storm sewer outfalls.
a. All disturbed areas will be paved, landscaped or revegetated to prevent
soil erosion and sedimentation.
3. Maintenance of all sediment\erosion control devices will remain the
responsibility of the contractor until the project is completed.
B. Fiscal Surety
I. Opinions of probable cost will be provided with the Final Drainage Report to
serve as the basis for the required fiscal surety.
Preliminary Drainage, Erosion Control and Water Quality Report
Rocky Mountain Innovation Initiative
D. Specific Details — Inlets and Storm Sewer
I. Runoff from the project site is collected by storm drain inlets and conveyed to
the regional infiltration pond. Inlets are placed in sumps as dictated by the
grading plan. The inlets are not sized for preliminary design. Detailed inlet
sizing calculations will be provided with the Final Drainage Report.
2. Inlets are also provided along East Vine Drive at the ends of the proposed
street improvements. These inlets will serve to intercept flow from the RM12
improved area for conveyance to the pond.
3. It is expected that the storm drain system will be extended into Vine Drive
and future IIP developments as those projects are constructed. A preliminary
layout for the future storm drainage system is provided on the Drainage and
Erosion Control Plan located in Appendix. The trunk systems within Vine
Drive are designed to accommodate the future runoff from this future
development. Conservative assumptions were made regarding future
hydrologic parameters. These assumptions are documented in the runoff
calculations contained in the appendix.
Preliminary Drainage, Erosion Control and Water Quality Report
Rocky Mountain Innovation Initiative
B. Specific Details —Detention
I. Stormwater detention for RMI2 will be provided in a regional infiltration pond
located south of Vine Drive. Although it is anticipated that this pond will
provide storm water management for much of the IIP site, it is only sized for
RMI2 at this time.
2. Outflow rate from the infiltration pond is calculated to be 1/2 the measure
infiltration rate. The reduction factor of 50% is used to account for potential
clogging of the filter media. The infiltration rates were measured by
CTL/Thompson using double ring infiltrometer testing. The results of those
test are included. in the appendix.
3. Detention volume required for RM12 is 0.82 acre-feet. This was determined
using the measure infiltration rate over the bottom area of the pond.
4. Water quality volume is not calculated separately since the entire 100-year
event is being treated through the process of infiltration. Therefore, the total
design volume of the pond is 0.82 acre-feet.
5. Water quality pre-treatment will be provided in the various inlets in the
stormwater collection system. The bottoms of the inlets will be deepened by
2.5 feet to allow for sedimentation. Additionally, oil interceptor devices (such
as the Nyloplast "Snout" or equivalent) will be placed in each inlet to separate
oil and other floatable contaminants from the storm water runoff. Details for
these will be provided at final design.
6. The required volume of 0.82 acre-feet is achieved at elevation 56.67 in the
pond. The emergency spillway for pond is at elevation 58.00. The additional
storage volume between these elevations is reserved for future development
within IIP.
® 5. A dewatering manhole is provide for the temporary installation of a pump
should the pond need dewatering for maintenance purposes. Long term
maintenance will be addressed with a operation and maintenance manual to be
developed during final design.
6. An emergency spillway is provided to convey the 100-year undetained flowrate
safely through the pond. The spillway general discharges towards the Gustov-
Swanson Natural Area to the south. An easement for this discharge has been
provided by the City. Additionally, an emergency spillway is proposed near an
existing break in the dike constructed along the river on the south side of
Natural Area. This spillway is also designed for the 100-year undetained event.
Riprap calculations will be provided for these at final design.
Preliminary Drainage, Erosion Control and Water Quality Report
Rocky Mountain Innovation Initiative
IV. DRAINAGE DESIGN CRITERIA
A. Development Regulations
Design criteria from the City of Fort Collins Storm Drainage and Design
Criteria and Construction Standards were followed for this drainage report.
B. Hydrological Criteria
I. Peak flow rates for the 10-year and 100-year storms have been calculated in
accordance with the City of Fort Collins Storm Drainage and Design Criteria
and Construction Standards. Please see these calculations in the Hydrology
section of the Appendix.
D. Hydraulic Criteria
1. The City of Fort Collins Storm Drainage and Design Criteria and Construction
Standards are used to determine the adequacy of the culverts, storm sewers,
inlets and street capacities throughout the project.
2. Analyses are performed using methodologies presented in Urban Storm
Drainage Criteria Manual Volumes 1 and 2; Urban Drainage and Flood Control
District, Denver, Colorado, September, 1999. Please see the various
computation spreadsheets in the Hydraulics section of Appendix I.
V. DRAINAGE FACILITY DESIGN
A. General Concept
I. Stormwater runoff from the proposed project will be collected by a system of
curb/gutter, storm drain inlets and storm drain pipes.
2: Runoff from Vine Drive will be collected by storm drain inlets and conveyed
via storm drain piping. The storm drain piping along Vine Drive is oversized to
provide storm drainage conveyance for the future improvements along Vine
Drive adjacent to the future phases of Inverness Innovation Park.
3. Stormwater will be managed using a regional infiltration pond located on the
south side of Vine Drive. This pond will provide both water quality and water
quantity treatment for the developed flows for phase I (RM12) and for future
projects within IIP. This pond will also provide treatment for future phases IIP,
although analysis for those uses will be provided along with future
development applications. At the present time, the regional pond will be used
for phase I only.
io Preliminary Drainage, Erosion Control and Water Quality Report
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Rocky Mountain Innovation Initiative
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Ill. DRAINAGE BASINS AND SUB=BASINS
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A. Major Basin Description
I. The project site lies within the Cache La Poudre Basin.
2. Portions of the project site lie within the FEMA 100-year floodplain (Zone AE)
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of the Cache La Poudre River, as shown on FIRM panel #08069C0977G, dated
June 17, 2008. Additional portions of the site lie within the FEMA 500-year
floodplain (Zone X). There are no new critical facilities or expansion of
existing critical facilities proposed with this project. A Floodplain Use Permit
will be required for the work proposed within the 100-year floodplain.
B. Existing Conditions
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I. As previously' mentioned, the existing site is currently developed as an
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industrial development, consisting of several metal buildings and a large gravel
storage area. The site is fairly flat with the terrain sloping gently to the south
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and southeast at approximately 0.33%.
2. Existing vegetation is minimal on the project site, with the exception of the
areas along the Lake Canal, which flows west -to -east along the northern
boundary of the site. This area is protected by an environmental buffer, and
will not be disturbed by the project.
3. Existing soils generally consist of clayey sands and top soil overlying sands and
gravels, as expected from the location of the project site near the floodplain of
the Cache La Poudre River. The soils report • for the project, entitled
"Geologic and Preliminary Geotechnical Report, 300-500 East Vine Drive",
dated September 15, 2008, was prepared by CTUThompson.
4. There are no off -site flows into the RMI2 site.
C. Developed Conditions
I. The proposed RM12 project consists of two office/industrial buildings to house
the Rocky Mountain Innovation Initiative. The parking areas will be paved with
asphalt and internal concrete walks and plaza areas will serve pedestrians.
2. East Vine Drive will be improved to minor arterial standards along the frontage
of the project.
Preliminary Drainage, Erosion Control and Water Quality Report
Rocky Mountain Innovation Initiative
I. INTRODUCTION
This report presents the pertinent data, methods, assumptions, and references used in
analyzing and preparing the final drainage, erosion control and water quality design for
the Rocky Mountain Innovation Initiative (RM12) at the Inverness Innovation Park (IIP)
in Fort Collins, Colorado.
The RM12 project can be considered phase I of the overall UP project. This report is
prepared in support of the Preliminary Development Plan for RM12, and the Overall
Development Plan for IIP.
II. GENERAL LOCATION AND DESCRIPTION
A. Property Location
I. The project site is located along the north side of East Vine Drive. The
current address of the parcel is 300 East Vine Drive, Fort Collins, Colorado.
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B. Description of Property
I. The existing site is currently developed as industrial, with several metal
buildings and a large gravel storage area. The proposed project is located on
the western portion of the overall Inverness Innovation Park project site, in
the area currently uses for outdoor storage.
Preliminary Drainage, Erosion Control and Water Quality Report
Rocky Mountain Innovation Initiative
TABLE OF CONTENTS
Title Page
Engineer's Certification
Table of Contents
I.
INTRODUCTION.......................................................................................:.... 3
II.
GENERAL LOCATION AND DESCRIPTION ............................................. 3
A.
Property Location
...............:......................................................................................................3
B.
Description of Property............................................................................................................3
III.
DRAINAGE BASINS AND SUB-BASINS
A.
.............:........................................4
Major Basin Description............................................................................................................4
B.
Existing Conditions....................................................................................................................4
C.
Developed Conditions..............................................................................................................4
IV.
DRAINAGE DESIGN CRITERIA....................................................................5
A.
Development Regulations........................................................................................................5
B.
Hydrological Criteria.................................................................................................................5
D.
Hydraulic Criteria......................................................................................................................5
V.
DRAINAGE FACILITY DESIGN5
....................................................................
A.
General Concept.......................................................................................................................5
B.
Specific Details — Detention.................................................................................................... 6
C.
Specific Details — Swales..........................................................................................................6
D.
Specific Details — Inlets and Storm Sewer...........................................................................7
VI.
SEDIMENT/EROSION CONTROL
..........................:.....................................8
A.
General Concept.......................................................................................................................8
B.
Fiscal
Surety ..............................................................................................................................8
VII.
CONCLUSIONS
...............................................................................................9
A.
Compliance with standards.....................................................................................................9
B.
Drainage Concept....................................................................................................................9
VIII.REFERENCES
................................................................................................... 9
IX. APENDICES..................................................................................................... 10
Preliminary Drainage, Erosion Control and Water Quality Report
Rocky Mountain Innovation Initiative
ENGINEER'S CERTIFICATION
I hereby state that this Preliminary Report for the drainage, erosion control and water
quality design of the Fort Collins Brewery project was prepared by me or under my direct
supervision for the owners thereof and meets or exceeds the criteria in the City of Fort
Collins Storm Drainage Design Criteria and Construction Standards.
Stacy J. Gowing
Registered Professional Engineer
State of Colorado No: 34290
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Preliminary Drainage, Erosion Control and Water Quality Report
For
Rocky Mountain Innovation Initiative
at Inverness Innovation Park
Fort Collins, Colorado
Prepared for:
URBAN DEVELOPMENT PARTNERS
C/O MICHAEL BELLO
1212 S. COLLEGE AVENUE
0 FORT COLLINS, CO 80524
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Prepared by:
ENGINEERING
171 NORTH COLLEGE AVENUE
FORT COLLINS, CO 80524
970-219-2834
AUGUST 12, 2009