Purcell, Goodwyn, & Campbell Lexington, KY 6 May 2015 Sandi Beechez, Chair, UK Master Planning TeamUniversity of Kentucky100 Administration Drive Dear Sandi Beechez,

This letter is in response to your notice to proceed dated 16 April 2015. Our consulting group, Purcell, Goodwyn, & Campbell, has done considerable analysis of the University of Kentucky Master Plan, and determined what we believe to be the best design solution.

This report will cover details within the watershed calculated from a point of interest. This point of interest is located at the intersection of Nicholasville Road and Alumni Drive within the confines of the University of Kentucky’s south campus grounds.

Through the analysis of collected data, we have designed a new detention basin system that we recommend be constructed in the area under consideration. Within this report, we will cover several aspects of the design including pre- and post-development conditions as well as the justification for our design.

Provided here is a summary of our design and the changes that would be necessary for implementation. Please respond to the group’s submission with any inquiries or concerns you may have regarding Phase II.

Sincerely,

Purcell, Goodwyn, & Campbell macypurcell@yahoo.comamgoodwyn11@aol.comcaca225@g.uky.edu

University of Kentucky’s Mater Plan Drainage, Storm Sewer, and Detention Systems

Phase 2

Lexington, KY 6 May 2015

By:

Macy Purcell

Angela Goodwyn

Chase Campbell

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Table of Contents

List of Figures……………………………………………………………………………..4

Executive Summary ............................................................................................................5

Introduction .........................................................................................................................7

Identification of Client………………………………………………………………….....7

Site Description and Location Map……………………………………………….............7

Scope………………………………………………………………………………………8

Objectives……………………………………………………………………………........8

Design Analysis…………………………………………………………………………...9

Recommendations .............................................................................................................10

Sources…………………………………………………………………………………...13

Appendix ….......................................................................................................................14

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List of Figures and Tables

Figure 1: Site Map……………………………………………………………………….14

Figure 2: Site Topographic Map…………………………………………………………14

Figure 3: Pre Development Watershed…………………………………………………..15

Table 1: Pre Development Summary…………………………………………………….15

Figure 4: Junction 1 Pre Development Hydrograph……………………………………..16

Figure 5: Junction 2 Pre Development Hydrograph……………………………………..16

Figure 6: Culvert Pre Development Hydrograph………………………………………...17

Figure 7: Post Development Watershed…………………………………………………17

Table 2: Post Development Summary…………………………………………………...18

Table 3: Post Develop Summary for Reservoirs…………………………………………18

Figure 8: Junction 1 Post Development Hydrograph…………………………………….18

Figure 9: Junction 2 Post Development Hydrograph…………………………………….19

Figure 10: Reservoir 1 Post Development Hydrograph………………………………….19

Figure 11: Reservoir 2 Post Development Hydrograph…………………………………20

Figure 12: Culvert Post Development Hydrograph……………………………………...20

Figure 13: Area of Reservoir 1…………………………………………………………..21

Figure 14: Area of Reservoir 2…………………………………………………………..21

Figure 15: Suggested Basin Locations…………………………………………………...22

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Executive Summary

Earlier this year, our team was given the opportunity to design a portion of

University of Kentucky’s Master Plan. This portion involved the design of two reservoirs

to collect runoff from a storm we deemed appropriate for the geographical location.

Initially, we spent the majority of our time gathering and analyzing data through the

ARC-GIS computer program to extract explicit information about the watershed we

would be taking into consideration. Once we acquired the necessary data, the next phase

of the plan began.

First, we chose a suitable design storm. The selection of the storm was based on

our engineering judgment, with the knowledge that a less frequent storm would require a

larger and more expensive design. Referencing the U.S. Department of Commerce’s

Rainfall Frequency Atlas of the United States we determined that Kentucky fell within

the boundaries of Type II rainfall distribution. With this information, we saw it

appropriate for our design storm to have a duration of 24-hours and a return period of 25

years. We concluded that having a smaller design storm would not require a significantly

greater expense or waste of space. The design storm produced 5 inches of rainfall, which

we input into the HEC-HMS software to simulate our inflow hydrograph.

Since we were designing two reservoirs, we had to split up the sub-basins

between two junctions connected to a culvert that would eventually feed into them. We

ran the storm through the watershed to acquire pre-development hydrographs and peak

flow for each junction and the culvert, shown in Table 1 & Figures 4-6 in the Appendix.

These peak flows were utilized to help us determine the parameters of each reservoir.

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We used the AASHTO Method, to determine the design volumes for the

reservoirs, but before we could use this equation, we needed to find tc. To do this, we

used the Watershed Lag Method from the United States Agricultural Department’s

Hydrology National Engineering Handbook in reference to the topographical map shown

in Figure 2. After the design volumes were obtained, it was a trial-and-error process to

determine the right size and fit for the designated locations of the reservoirs, shown in

Figures 13 & 14. We chose to add four orifices to each reservoir. We designed Reservoir

1 to have an outflow of 100cfs and Reservoir 2 to have 250cfs.

Finally, once the reservoirs were added to HEC-HMS, it was necessary to

determine if our design was satisfactory. We ran the storm through our entire system

once more shown in Figure 7, to obtained our final results. The post-development

information is located in Tables 2 &3 as well as Figures 8-12. After analysis, all of the

hydrographs were acceptable, and the outflows for our reservoirs met each of our

designs.

Our final recommendation calls for the construction of two detention basins, one

that covers 5 acres and has a depth of 5 feet, and another that covers 3 acres and is 5 feet

deep. More design specifications can be found in subsequent sections of this report.

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Introduction

Identification of Client

On February 27, 2015, our client, the University of Kentucky, represented by Ms.

Sandy Beechez contacted us to proceed with Phase 1 of the design for the drainage

system located on south campus.

Site Description and Location Map

The location covers the portion of the University of Kentucky’s south campus,

which includes Alumni Drive, Commonwealth Stadium, the Arboretum, K Lot parking

lot, as well as various buildings. The land in the watershed can be classified as mixed

use. After delineating the watershed, the area was calculated to be 117.89 acres. Figure 1

in the Appendix shows an aerial view of the location, with reference points labeled on the

map.

Figure 15 shows the location map with the placement of our designed basins. In

the figure, Reservoir 1 is shown on the left, and Reservoir 2 on the right. As you can see,

the reservoirs fit nicely within the spaces we used in the design. This means that all of the

current infrastructure on this portion of south campus will not have to be altered very

much. The only alterations that will have to be made would be the uprooting and

replanting of trees and vegetation. Other than the lack of green space, our site is

predominately covered by Commonwealth Stadium and the impervious parking lot that is

connected to it.

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Scope of Study

In 2006 two women were sucked into a storm drain due to record rainfalls and

drowned at the intersection of Nicholasville Road and Alumni Drive. This tragic event

caused the University of Kentucky to take steps to alleviate flooding in the area. The

University is removing a parking lot at the entrance to the Greg Page Apartments and is

replacing it with a new lot that will be built on top of a water detention basin. The scope

of this portion of the study is to analyze and design an adequate watershed drainage

system.

Objectives

The purpose of this study is to design an adequate drainage system for south

campus of the University of Kentucky. The location of this study is known to have both

drainage and retention problems. The delineation of the watershed has provided

necessary data for the curve number calculations. The objective is to prevent runoff

volumes that are safe to the public and the environment during a storm event. As a

group, we decided it would be feasible to reduce flow from the watershed by 60%.

Because the University holds safety in such high regard, safety will be a key

factor in our decision making process. Overall, the establishment of the drainage system

must enhance the level of safety for locals, students, and the University of Kentucky

Campus as a whole.

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Design Analysis

Once the watershed information was input into the HEC-HMS software, we tested

the watershed to see its response to 5” of rainfall, or a 24-hour, 25-year storm. Noting the

output data, which can be seen in Table 1 and Figures 4-6, we began the design process

through procedures noted earlier.

Upon completion of our detention basin design, the group considered its

effectiveness. To determine if the design would meet our objectives and fulfill the clients

needs, we analyzed the data output from HEC-HMS.

As noted previously in the Objectives section, one primary goal was to reduce the

outflow from the watershed by 60%. The combined outflows from the watershed before

development totaled just over 1100cfs. Thus, to reduce by 60%, the post-development

outflow would have to be less than or equal to 440cfs.

We determined that our design successfully met this objective. After adding two

detention basins to the watershed model, we once again modeled a 25-year storm using

the design. The HEC-HMS software confirmed our calculations, and showed that our

design performed better than a 60% reduction in flow.

The group also considered the objective to minimize the area devoted to detention

basins. Through several design iterations, the group successfully managed to develop the

final plan which calls for two basins. The combined area of these basins is eight acres.

This represents only 4.5% of the total watershed area. Similarly, since the basins will be

grass-lined, they do not take away green space from an area that has a significant

proportion of open green space.

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Next, the design does not require the demolition or deconstruction of any existing

infrastructure. The group focused on preventing any unnecessary demolition in order to

decrease construction costs. Construction costs will be reasonably low because of the

location of the planned basins. As can be seen in Figure 13 of the Appendix depicting the

planned locations, the basins border Alumni Drive and the K Lot parking lot on UK’s

campus. Equipment used in construction could be staged in the area already being used

for Commonwealth Stadium renovations, and would not have to travel far to the work

site.

Ultimately, the design successfully fulfilled all of the group’s objectives, and

served the needs of the client.

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Recommendations

Based on the design analysis, our group recommends the implementation of our

design. Given that the design meets the objectives of the client, we believe that it would

serve their needs well.

Implementation of our design would require the construction of two detention

basins. The first and larger of these basins is to be located between Alumni Drive and the

Greg Page Apartments, and is to cover an area just over 5 acres. The second basin should

be slightly smaller than the first at only 3 acres. It is to be located just past the first basin,

but on the opposite side of the road, bordering the K Lot parking lot. The precise

locations can be seen in Figure 15 of the Appendix.

The larger basin is intended to handle a large majority of the runoff from the

Commonwealth Stadium parking lot and the surrounding parking lots. These lots make

up a large percentage of the watershed, and prevent water from infiltrating. Drains

should be installed in the parking lot and should connect to culverts installed beneath

Alumni Drive to divert water from the lots and into the larger basin. Similarly, 5 32”

culverts should be use to drain the water from the culvert into the existing grass channel

that parallels Alumni Drive. This channel connects to the culvert that lets water out of the

watershed and which serves as the outlet of the watershed.

The smaller basin is designed to handle flows from the open space and

grassy/forested areas. Since these areas allow more water to seep into the ground, the

runoff is less than with the parking lots. Four 24” culverts should allow water to flow out

of the basin.

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Both basins should have side slopes with one foot of vertical rise to every two feet

of horizontal distance. Thus, the basins should have trapezoidal cross sections. Because

of the irregular shape of the basins, the group found it difficult to calculate the volume of

these odd shapes. Instead, we initially designed these basins with vertical sides, since the

volume could be calculated by multiplying the area by the height. In effect, adding sloped

sides to the basins adds a slight safety factor, because the volume will be greater than

originally designed. This increased volume increases the effectiveness and level of safety

of the basin, without a significant increase in cost.

We recommend that this design be implemented very soon, in order to coordinate

with work that is currently going on. At the time of this report, considerable work is

being done to renovate the parking lot adjacent to the UK Arboretum. If work is started

soon, it would save time, and would prevent possible damage to a completed parking lot

by construction equipment.

Our final recommendation is to use the design presented by this report.

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SourcesGupta, Ram S. Hydrology and Hydraulic Systems. Long Grove, IL: Waveland, 2008.

Print.

http://www.nws.noaa.gov/oh/hdsc/PF_documents/TechnicalPaper_No40.pdf

https://www.codot.gov/programs/environmental/water-quality/documents/drainage-

design-manual/drainagedesignmanual_chapter12_storagefacilities.pdf

http://directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=27002.wba

http://www.hec.usace.army.mil/software/hec-hms/documentation.aspx

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Appendix

Figure 1: Site Map

Figure 2: Site Topographic Map

Alumni Dr.Nicholasville Rd.

14

Figure 3: Pre Development Watershed

Table 1: Pre Development Summary

Peak Outflow (cfs) Total Outflow (in)

Junction 1 449.7 3.79

Junction 2 728.3 4.82

Culvert 1175.7 4.38

15

Figure 4: Junction 1 Pre Development Hydrograph

Figure 5: Junction 2 Pre Development Hydrograph

16

Figure 6: Culvert Pre Development Hydrograph

Figure 7: Post Development Watershed

17

Table 2: Post Development Summary

Peak Outflow (cfs) Total Outflow (in)

Junction 1 449.7 3.79

Junction 2 728.3 4.82

Culvert 317.9 4.38

Table 3: Post Develop Summary for Reservoirs

Peak Storage (AC-FT)

Peak Elevation

(Ft)

Peak Inflow (cfs)

Peak Outflow

(cfs)

Total Inflow

(in)

Total Outflow

(in)

Reservoir 1

8.0 3.9 449.7 105 3.79 3.79

Reservoir 2

11.9 3.7 728.3 213 4.82 4.82

Figure 8: Junction 1 Post Development Hydrograph

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Figure 9: Junction 2 Post Development Hydrograph

Figure 10: Reservoir 1 Post Development Hydrograph

19

Figure 11: Reservoir 2 Post Development Hydrograph

Figure 12: Culvert Post Development Hydrograph

20

Figure 13: Area of Reservoir 1

Figure 14: Area of Reservoir 2

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Figure 15: Suggested Basin Locations

22