main

street dam

feasib

ility

stu

dy

MAIN STREET DAM REMOVAL

FEASIBILITY STUDY20

12

02

ACKNOWLEDGEMENTS

COLUMBUS DOWNTOWN DEVELOPMENT CORPORATION

Guy Worley, CEO

Amy Taylor, COO

Milt Lewis, Director of Construction Services

CITY OF COLUMBUS

Dax Blake, PE, Administrator, Division of Sewerage and Drainage

Mike Griffi th, PE, Division of Sewerage and Drainage

Erin Miller, Environmental Steward

STANTEC

Bryon Ringley, PE, Principal

Scott Peyton, PE, Senior Associate

Travis White, PE, SI, Senior Project Engineer

Brad Rodgers, PE, CHMM, Senior Associate

Cody Fleece, Senior Ecologist

Rich Williams, PhD, PE, Senior Geotechnical Engineer

Jenny Rytel, PG, Geologist

Mary Murphy, Administrative Assistant

MSI DESIGN

Keith Myers, FASLA, Principal

Darren Meyer, RLA, Associate Principal

Andrew Overbeck, AICP, Urban and Regional Planner

Aron Fraizer, ASLA, Associate

Charles Benick, Project Designer

RESOURCE INTERNATIONAL

Michelle Eckels, CPG, Director of Environmental Services

Mark Ward, PS, Survey Manager

ASC GROUP

Shaune Skinner, President

Al Tonetti, Cultural Resource Specialist

COLDWATER CONSULTING

Kristen Risch, Senior Restoration Specialist

SHELLEY, METZ, BAUMANN, HAWK

Jon Beier, PE, LEED AP BD+C

main

street dam

rem

ova

l feasib

ility

stu

dy

03

tab

le o

f conte

nts

& a

cknow

led

gm

ents

02 acknowledgements and table of contents

04 executive summary

06 planning context

08 recent investment

10 river evolution

12 feasibility study

14 natural channel design

16 concept plan

26 implementation

TABLE OF CONTENTS

04

RIVERFRONT RENAISSANCE

Columbus is in the midst of a riverfront renaissance. Beginning

with North Bank Park in 2004, and continuing with the opening of

the Scioto Mile and the Scioto Audubon Metro Park, Downtown’s

riverfront has been transformed. The 2010 Downtown Columbus

Strategic Plan built on this momentum by proposing the removal

of the Main Street Dam and the creation of a greenway along the

Scioto River as the beginning of a new green corridor through the

heart of the city. The Scioto Greenways Feasibility Study , funded

by the Columbus Downtown Development Corporation and the

City of Columbus, explores the environmental, engineering, and

land planning challenges associated with removal of the dam. The

study provides a technical solution that meets these challenges

and shows how a naturalized river corridor and parkland will enable

Downtown to truly embrace the Scioto River.

A NEW URBAN RIVERFRONT

The downtown portion of the Scioto River is currently an overly-

wide, slow-moving pool of sediment-laden water, due to the Main

Street Dam. Removing the dam would allow the water course to be

narrowed and green space to be added along its edges. Building

on the public and private investment in The Scioto Mile, the urban

riverfront would be expanded with 33 acres of new green space

that connects Downtown to the river and the Scioto Peninsula. The

Master Plan Concept includes plaza and event spaces that enhance

the Scioto Mile. Phase one improvements focus on new greenways

on both sides of the Scioto River that would tie into the existing

Downtown and regional bikeway system and allow for new access

at the river level. The greenway transitions to a naturalized river edge

condition designed to restore river habitat and withstand fl ood events.

A RESTORED RIVER

In addition to enhancing the public realm, removing the Main Street

Dam allows for the implementation of a natural channel design that

restores river habitat. Today, the downtown portion of the Scioto

River is designated as a Modifi ed Warm Water Habitat by the Ohio

EPA due to the lower expectations for aquatic habitat and biological

success in this area. The Scioto River can attain a higher aquatic

habitat use if the physical impairments are removed and the natural

form and function of the river is restored. A healthier river, along

with new pathways and recreational access, will bring people to the

EXECUTIVE SUMMARY

riverfront and connect the neighborhoods and districts along the

river corridor.

STRONGER CONNECTIONS

In addition to strengthening the connection between Downtown

and the Scioto Peninsula, the removal of the Main Street

Dam will better link The Ohio State University to Downtown

Columbus. With the removal of the 5th Avenue Dam at OSU on

the Olentangy River well underway, there will be a free-fl owing,

navigable river from the campus area through Downtown

Columbus. These two projects set the stage for the exploration

of removing or modifying other dams upstream on the Olentangy

River, with the complete realization creating a naturalized river

corridor from Highbanks Metro Park to the Scioto Audubon

Metro Park through OSU and Downtown. This 16.5-mile green

link would be unmatched in any major U.S. city today.

UNLIMITED TRANSFORMATIVE POTENTIAL

Improving the health of the river increases its value to the

community, contributing to a more prosperous, competitive

metropolis for the 21st century. The removal of the Main Street

Dam is an important fi rst step in carrying out the vision of

a restored river corridor through Downtown Columbus and

beyond.

• Build on recent park investments

• Reduce river width

• Clean and restore river habitat

• Enhance greenway connections

• Improve access to river

• Create economic value and spur redevelopment

• Improve linkages between downtown and Scioto

Peninsula

• Work within existing 100 year fl oodplain

PROJECT GOALS

05

exe

cutiv

e s

um

mary

main

street dam

rem

ova

l feasib

ility

stu

dy

“Building on the Scioto Mile, this new urban riverfront downtown could be expanded with 33 acres of new green space.”

BEFORE

AFTER - MASTER PLAN CONCEPT

06

EARLY HISTORY

Throughout Columbus’ history, the Scioto River has been

evolving. In place by the mid-1800s, the original timber dam

was built to provide water for the feeder canal that connected

the Scioto River to the Ohio and Erie Canal. Over this period,

the river channel has been constantly changing, along with

the city. Smaller river channels were fi lled in, islands were

removed and the river course was altered to accommodate

bridges, railroads, industry and other development.

RESHAPING THE RIVER

The most signifi cant changes to the river corridor occurred

after the fl ood of 1913. The fl ood destroyed the original

timber dam and the river width narrowed closer to its natural

watercourse. The resulting mud-fl ats that were exposed

created an unsightly appearance in Downtown. The Main

Street Dam was built in 1921 in order to create a more

aesthetically pleasing riverfront, and resulted in a wider river.

This river pool was built in concert with other Civic Center

riverfront improvements, including City Hall. The Main Street

Dam was altered in 1929 to add another foot and half in height

to the dam that created the river width of the Scioto River

today.

THE RIVER TODAY

Over time, the Main Street Dam has prevented the passage

of sediment and limited the navigability of the Scioto River.

In the late 1980s, efforts were made to dredge the river to

deepen the channel and allow for water craft use, but the

river soon deposited more sediment and further efforts were

not undertaken. Additionally, by this time the original 1920s

improvements had begun to age with the concrete revetments

and balustrade along the river edge crumbling into the river.

As part of the improvements to North Bank Park and the

Scioto Mile, this revetment condition has been removed and

the river edge has been naturalized. The balustrade along

Civic Center Drive has also been restored and renovated.

RIVER EVOLUTION

REMAINS OF THE FEEDER CANAL

INDUSTRY ALONG THE SCIOTO RIVER

DAMAGE FROM THE 1913 FLOOD

THE MAIN STREET DAM TODAY

1920

1939

1868

1899

1941

1845

main

street dam

rem

ova

l feasib

ility

stu

dy

river evo

lutio

n

BROAD STREET

HIG

H S

TR

EET

• Feeder Canal and Sluice

BROAD STREET

HIG

H S

TR

EET

• Timber Dam

BROAD STREET

HIG

H S

TR

EET

• Scioto Peninsula Filled In Remaining Islands

BROAD STREET

HIG

H S

TR

EET

• Post - 1913 Flood Condition

• Timber Dam Destroyed

BROAD STREET

HIG

H S

TR

EET

• Wider Main Street Dam built to replace

timber dam

BROAD STREET

HIG

H S

TR

EET

• Taller Main Street Dam

• Current River Width 07

“Since the founding of Columbus the Scioto River has been evolving and changing.”

08

LINKING DOWNTOWN AND NEIGHBORHOODS

From Worthington to Downtown Columbus, seven low head dams

interrupt the natural fl ow of the Olentangy River. These dams

impair aquatic habitat, degrade water quality, limit recreational

opportunities, and create a safety hazard. The 2010 Downtown

Columbus Strategic Plan advanced a strategic vision for removing

these dams to create a 16.5 mile greenway corridor that connects

Scioto Audubon Metro Park and Downtown to numerous

neighborhoods and High Banks Metro Park to the north. Cleaning

the rivers and removing low head dams would restore the natural

river course, reintroduce river habitat as a tranquil amenity, and

create more green space and recreational opportunities. This

catalytic idea builds on the recent investment and current plans to

restore river health. With North Bank Park, the Scioto Mile, and the

Scioto Audubon Metro Park, nearly all of the downtown riverfront

park system has been remade into a world-class park destination.

However, this investment is incomplete until the river health is

restored. The City of Columbus has taken the fi rst step toward a

healthy river with its efforts to implement a $2.5 billion wet weather

management program to reduce the occurrence of combined sewer

overfl ows. The 5th Avenue Dam removal represents the fi rst step in

restoring the natural river course and enhancing habitat along this

corridor. With the removal of the Main Street Dam, the initial link in

this river greenway system will be created between The Ohio State

University and Downtown Columbus. In time, this model can extend

north along the river corridor, connecting neighborhoods to the river

and to Downtown Columbus.

COMMUNITY CONNECTIONS

HIGHBANKS METRO PARK

THE OHIO STATE UNIVERSITY

DOWNTOWN COLUMBUS

SCIOTO AUDUBON METRO PARK

• Connected – links neighborhoods, communities, and

recreational opportunities

• Healthy – promotes physical activity and bike

commuting in a beautiful and engaging environment

• Smart – provides educational opportunities for the

entire community to learn about the importance of

protecting our river systems

• Sustainable – restores the river habitat and increases

biodiversity

• Prosperous – raises property values adjacent to the

greenway corridor and encourages reinvestment

COMMUNITY BENEFITS

Sc

i ot

o

R

iv

er

Ohio State University

5th Avenue Dam

Worthington

Highbanks Metro Park

Scioto Audubon Metro Park

Clintonville

Downtown Columbus

Main Street Dam

Ol e

nt

an

gy

R

i ve

r

09

main

street dam

rem

ova

l feasib

ility

stu

dy

pla

nnin

g c

onte

xt

main st. dam

main st. dam removal feasibility study area

“The Scioto-Olentangy Greenway Corridor would create a 16.5 mile green link through the heart of the city.”

STUDY AREA

10

RECENT IMPROVEMENTS

The RiverSouth area and Downtown Columbus riverfront have

seen hundreds of millions of dollars of public and private

investment over the past decade. In addition to North Bank Park

and the Scioto Mile, surrounding street infrastructure has been

improved to allow for two-way traffi c, and there are two new

bridges across the Scioto River. New residential development at

the Annex at River South has also come online to complement

the existing residential properties Downtown by providing

affordable rental options. The renovated Lazarus Building offers

700,000 square feet of offi ce space and prime street-level retail

in a LEED Gold certifi ed building.

DEVELOPMENT OPPORTUNITIES

The Main Street Dam removal project will capitalize on these

investments and be the catalyst for further redevelopment.

Across the country, dam removal and river restoration projects

have been shown to enhance the economic value of property,

businesses and communities. This new 33-acre greenway in

the heart of Downtown will draw people to the waterfront and

encourage interaction at the river level. Building on the recent

completion of two new bridges across the Scioto River that

provide better access to COSI and other attractions, this new

riverfront greenway will further help the west bank of the river

to embrace the riverfront and Downtown, acting as a catalyst

for redevelopment of vacant and underutilized property on the

Scioto Peninsula and East Franklinton.

RECENT AND FUTURE INVESTMENT

• The 33 acre greenway will increase private

development and attract hundreds of thousands of

visitors annually

• Surrounding this revitalized river and greenway is

nearly 100 acres of vacant and underutilized land

that is primed for redevelopment, especially on the

Scioto Peninsula and East Franklinton.

• The Main Street Dam removal project will support

as many as 350 new jobs in the region

NORTH BANK PARK

THE SCIOTO MILE

MAIN STREET BRIDGE

SCIOTO AUDUBON METRO PARK

ECONOMIC IMPACT

11

main

street dam

rem

ova

l feasib

ility

stu

dy

recent in

vestm

ent

NORTHBANK

PARK

MAIN STREET

BRIDGE

RICH STREET

BRIDGE

SCIOTO AUDUBON

METRO PARK

SCIOTO

MILE

COLUMBUS

COMMONSLAZARUS

BUILDING

“The Main Street Dam Removal project seeks to build on the

investment and momentum along the Downtown Columbus riverfront”

RECENT INVESTMENT

POTENTIAL FUTURE REDEVELOPEMNT

12

OBJECTIVES

The Main Street Dam Removal Feasibility Study had four

primary objectives:

• Develop a thorough understanding of the river and the

land and structures within and around it.

• Determine the potential environmental and engineering

issues involved in removing the dam, particularly the

impact on the 100 year fl oodplain

• Develop a concept plan for the river channel that restores

the natural river course and improves water quality

• Expand the concept plan to show how the reclaimed

public land on either side of the river could be reused as

urban park space

ADDRESSING THE CHALLENGES

Throughout this project numerous issues were addressed:

• Historic Preservation: Study outlined changes made to

the Scioto River over time and determined that the Main

Street Dam is not in the Civic Center Historic District,

although the project is subject to Section 106 of the

National Historic Preservation Act of 1966.

• Ecology: Determined that the dam is inhibiting the river

from reaching its potential use attainment designation

of Warm Water Habitat, and that dam removal and river

restoration will improve habitat for native fi sh and mussel

species that should reside in the Scioto River.

• Hydrogeology: Found that there is a relationship between

FEASIBILITY STUDY

a permeable gravel aquifer and the Scioto River that

both discharges and receives water from the river.

• Sediments: Sediment samples contained some con-

taminants above residential levels. Ohio EPA indicates

preliminarily that these contaminants may not need to

be removed but could be reused under certain condi-

tions.

DEVELOPING THE CONCEPT PLAN

With this baseline information determined, a Concept Plan

for the dam removal and addition of parkland was created

to demonstrate what could be done with the narrowed river

channel in terms of new open space and restored river habitat

in Downtown. This plan adds 33 acres of additional green

space to Downtown and offers a new pedestrian linkage be-

tween Downtown and COSI in addition to enhanced river rec-

reation opportunities and extensive new pathways and river

viewpoints. The proposed dam removal, restoration design,

and park improvements were then modeled and compared to

existing conditions along the river. No rises in one-percent an-

nual chance fl ood elevations will occur. The Standard Project

Flood will remain contained within the fl oodwall. Average an-

nual river elevations will decrease by approximately seven feet

immediately upstream of the former dam location. Likewise,

the structures and bridges within the river corridor were also

assessed and changes recommended in order to mitigate

impacts of the river lowering.

CONCERNS RESPONSES

1. Utility Crossings will be exposed by lower water

levels and impacted by increased scour.

2. Combined Sewer Overfl ow odor will increase due

to lower water levels.

3. Piers of existing bridges will be exposed by drop-

ping the water level.

4. Foundations near river for OSIS, fl oodwall, and

adjacent buildings could be damaged by the

lowering of the river.

5. Flood levels could be adversely impacted by

removing the dam.

1. Proposed river bed will maintain cover above

existing utility crossings.

2. Existing lines will be extended to ensure that the

submerged condition remains, containing odor.

3. Bridge piers will either be on the banks of the new

river, or will have extended caps on piers to ad-

dress concerns.

4. Groundwater in the area feeds the river and is

currently cut-off by the fl oodwall. The groundwater

conditions today will not be altered.

5. The 100 year fl oodplain extents are not altered

as part of this project, allowing the river and park

system to handle fl ood events.

13

main

street dam

rem

ova

l feasib

ility

stu

dy

feasib

ility

stu

dy

BEFORE

AFTER

“With the removal of the Main Street Dam the Scioto River will be narrowed by

nearly half and Downtown Columbus will gain 33 acres of new riverfront park land.”

14

RIVER NARROWINGNATURAL CHANNEL DESIGN

MODELING OF THE CONCEPT

As part of the Feasibility Study, the impact of the dam removal

and the implementation of a natural channel design for the Scioto

River were assessed. Modeling of the proposed conditions

resulted in no rises in the 1% annual chance of fl ood elevations

and found that the Standard Project Flood will remain contained

within the fl oodwall. In general, the 100 year fl oodplain extents are

not altered as part of this project. In certain areas, especially in

front of COSI, it actually improves slightly (see diagram at right).

IMPACT ON THE RIVER LEVEL

While the impact of the dam removal is greatest immediately

upstream of the former dam location, resulting in a seven foot

decrease in the water surface elevation based on average annual

fl ow conditions, the entire river corridor will see a decrease

in channel width. The sections at right illustrate this change

in channel width and the added greenway (based on average

annual fl ow conditions).

HABITAT RESTORATION

Removing the dam and implementing a natural channel design

will result in an increase in ambient dissolved oxygen, a reduction

in low fl ow water temperatures, and an improvement of habitat

diversity and aquatic habitat. The natural channel design will also

provide the necessary substrates and fl ow regimes needed for the

recolonization of fi sh and mussel species that were once found

in this segment of the Scioto River. The dam removal will also

allow these species to migrate upstream, increasing the diversity

of those aquatic communities. Due to these improvements, an

increase in the Qualitative Habitat Evaluation Index from the Ohio

EPA is expected for this segment of the Scioto River.

HIG

H S

TR

EET

BROAD STREET

SECTION 1

SECTION 2

SECTION 3

Existing Channel

Proposed Channel

CHANNEL WIDTH

HIG

H S

TR

EET

BROAD STREET

Existing 100 year fl oodplain

Proposed 100 year fl oodplain reduction

FLOODPLAIN WIDTH

• Recreates and restores a more natural channel for the

Scioto River

• Has a positive impact on water quality, river health and

aquatic habitat

• Provides for the recolonization of native fi sh and

mussel species

• Allows for upstream migration, increasing the diversity

of these aquatic communities.

ENVIRONMENTAL BENEFITS

• Existing crossing = 495 feet

• Proposed crossing = 250 feet

• Width reduction = 245 feet

• Existing crossing = 495 feet

• Proposed crossing = 245 feet

• Width reduction = 250 feet

• Existing crossing = 570 feet

• Proposed crossing = 270 feet

• Width reduction = 300 feet

SECTION 1

SECTION 2

SECTION 3m

ain

street dam

rem

ova

l feasib

ility

stu

dy

natu

ral c

hannel d

esig

n

570’ Existing Crossing

270’ Proposed Crossing

570’ Existing Crossing

495’ Existing Crossing

245’ Proposed Crossing

495’ Existing Crossing

250’ Proposed Crossing495’ Existing Crossing

FEDERAL

COURTHOUSE

BICENTENNIAL

PARK

VETERANS

MEMORIAL

COSI

SCIOTO MILE

PROMENADE

HEALTH

DEPARTMENT

SITE

SCIOTO

RIVER

SCIOTO

RIVER

SCIOTO

RIVER

SCIOTO

RIVER

SCIOTO

RIVER

SCIOTO

RIVER

495’ Existing Crossing

15

EXISTING

PROPOSED

EXISTING

PROPOSED

EXISTING

PROPOSED

1616

INTRODUCTION

With the engineering parameters of the Main Street Dam Remov-

al defi ned, the project team created a Master Plan Concept for

the narrowed river, restored river edge and adjacent greenway.

The implementation of a natural channel design allows for the

creation of approximately 33 acres of ground that can be used

to meet fl oodplain requirements, restore river habitat and create

greenway connections.

New pathways on both sides of the Scioto River tie into the

existing downtown and regional bikeway system and allow for

interaction and access at the river level. The park pathway and

plaza areas transition to naturalized river edge condition that is

designed to withstand fl ood events. The greenway will link into

the existing bikeway system with bike paths and landscaped

park areas. This greenway corridor will connect The Ohio State

University to Downtown Columbus and provide recreational

opportunities such as cycling, canoeing and kayaking. Taken

together, these improvements will create an opportunity for the

public to experience and interact with the river in a more natural

state.

The Master Plan Concept seeks to build on recent park invest-

ment along the downtown riverfront from North Bank Park to

the Scioto Audubon Metro Park. Elements of the Scioto Mile

will be enhanced with new plaza and event spaces, especially

at the Town Street Prow that will have a two-level overlook. On

the west side of the river, an extension of the plaza and lawn in

front of COSI will create an expanded event space. Building on

the theme of connections, a proposed pedestrian bridge will

directly connect COSI and the Scioto Peninsula to the Scioto

Mile Promenade and Downtown Columbus helping to visually

and physically link these two nodes of activity.

With these improvements, Downtown will no longer turn its back

on the Scioto River. Instead, it will be able to use the river for

recreation, admire it for its natural beauty and celebrate it as the

“central park” of Downtown Columbus.

MASTER PLAN CONCEPT

PROJECT PHASING

To enable the effi cient implementation of this project, the pro-

posed Master Plan Concept improvements have been divided

into two phases. The Master Plan diagram at right highlights

major plan components under each phase.

Phase One components focus on dam removal, river channel

formation, river restoration and associated greenway and bike

path components. Phase Two components include event and

plaza spaces, additional hardscape and landscape features and

fountains, and a pedestrian bridge across the Scioto River con-

necting the Scioto Peninsula to the Scioto Mile Promenade. Ren-

derings of all Phase One components are shown on subsequent

pages of this report. An Implementation section follows that

outlines the preliminary estimate of probable cost for Phase One.

• Removal of concrete low head dam south of the Main

Street Bridge

• Removal of accumulated sediment behind dam

• Restoration of a more naturalized and narrower river

course and channel topography with the creation of

pools, riffl es, and glides that improve river fl ow and

habitat.

• Creation of a stabilized riveredge and naturalized

river bank using bioengineering methods – no riprap

or concrete walls with the exception of limited, target

areas for public access to the river edge.

• Construction of a greenway system with bike paths,

park space, and connections to existing public parks

and amenities.

PHASE ONE IMPROVEMENTS

17

122222222222222222

222222222222222222222222

3333333333333333333333333

44444444445555555

8888

66666666666

777777

main

street dam

rem

ova

l feasib

ility

stu

dy

concep

t p

lan

“Downtown Columbus will no longer turn its back on the Scioto River. Instead, people will be able to use it for recreation, admire it for its natural beauty and celebrate it as

the ‘central park’ of Downtown Columbus.”

PHASE ONE COMPONENTS

1. Restored River Channel: Reconfi gured river channel

sculpted with pools, riffl es and glides to create a more

natural and healthy river environment, supporting a diverse

aquatic habitat.

2. Restored River Edge: Bio-engineered, stabilized and

vegetated river edge with native plant material and riparian

habitat. The river edge transitions from native plantings to

manicured parkland upslope of the leisure trail.

3. Leisure Trail: Continuous 12-foot-wide leisure trail on both

the east and west banks that is integrated with the Scioto-

Olentangy Bikeway and larger regional bike trail system.

4. Scioto Quay: Lower level walkway along river’s edge. The

quay brings people to the river and provides a link in the

trail system.

PHASE TWO COMPONENTS

5. Town Street Prow: Two-level plaza space that preserves

the existing Town Street Prow and creates a lower-level

overlook to the river and West Bank. The two levels are

connected by a grand stair along the south edge of the

existing Prow.

6. East Landing: Urban plaza and event space that provides a

connection between Downtown Columbus, the Scioto Mile

Promenade and the pedestrian bridge.

7. Event Plaza and Lawn: Extension of the plaza and lawn

space in front of COSI to create a venue for expanded

festivals, events and exhibits.

8. Pedestrian Bridge: Signature bridge for pedestrians con-

necting COSI and the Scioto Peninsula to the Scioto Mile

Promenade and Downtown Columbus.

3333333333333333333333

1

222222222222

3333333333333333333333333

22222222222

MASTER PLAN CONCEPT

18

BEFORE

AFTER - PHASE ONE

19

main

street dam

rem

ova

l feasib

ility

stu

dy

concep

t p

lan

“This project has such tremendous potential to transform the image of our city.”

- public comment

20

BEFORE

AFTER - PHASE ONE

21

main

street dam

rem

ova

l feasib

ility

stu

dy

concep

t p

lan

“Removing the dams will help clean up the river and improve the experiences throughout the neighborhoods along the river corridor into Downtown Columbus and

the Scioto Audubon Metro Park.”- public comment

22

BEFORE

AFTER - PHASE ONE

23

main

street dam

rem

ova

l feasib

ility

stu

dy

concep

t p

lan

“This idea is groundbreaking. It returns the river to its natural fl ow and uses a sustainable

model for fl ood management.”- public comment

24

BEFORE

AFTER - PHASE ONE

25

main

street dam

rem

ova

l feasib

ility

stu

dy

concep

t p

lan

“Ohio means ‘beautiful river.’ As the state capital, Columbus could be the showcase of what a natural, beautiful river looks like.

I would dedicate my life to making this idea a reality.”- public comment

26

WHAT WILL IT COST

Based on the concept developed as part of the Feasibility Study,

a preliminary estimate of probable cost was prepared. Below is

the estimate for Phase One improvements, which is divided into

several project categories:

• Existing Conditions / Site Preparation and Dam Removal:

Involves project mobilization and the demolition of the Main

Street Dam.

• River Restoration: includes all necessary earthwork as part

of removing sediment and adding necessary fi ll to create

the adjacent parkland, the creation of the new river channel,

and the restoration of the naturalized river edge itself.

• Utility Work: includes required extensions and protection of

existing utilities that are exposed as part of the lowering of

the river level.

IMPLEMENTATION

• Greenways (Transportation): includes all pathways and bike-

paths and associated hardcape improvements.

• Greenways (Park Space): includes all park space improve-

ments adjacent to pathways and bikeways.

•

MOVING FORWARD

The Main Street Dam Removal will require a coordinated effort

among multiple regulatory agencies and the private and public

sectors to achieve implementation. This new 33-acre green

space will improve the health of the river and increase its value

to the community. Building on recent park investment and

planned improvements, this new “central park” will be a green

link that both creates a more cohesive Downtown and connects

it to the wider city. Taken together, these improvements to the

river corridor will help the city become a more prosperous and

competitive metropolis for the 21st century.

Existing Conditions / Site Preparation

Dam Removal

River Restoration

Utility Work

Greenways (Transportation)

Greenways (Park Space)

River Restoration

$20,194,304

57%

Utility Work

$3,995,493

11%

Greenways (Transportation)

$3,878,757

11%

Greenways (Park Space)

$4,109,125

12%

Existing Conditions / Site Preparation

$3,003,212

8%

Dam Removal

$325,415

1%

27

main

street dam

rem

ova

l feasib

ility

stu

dy

imp

lem

enta

tion

BEFORE

AFTER - PHASE ONE