Scioto Mile and Greenways

Challenge

• Restore the section of the Scioto River between North Bank Park and the Main Street bridge to a natural, free-flowing condition.
• Use the streambed to mitigate localized flooding, increase stormwater management capacity, and enhance water quality in the river.
• Enhance biodiversity by increasing habitat with native plant species.
• Strengthen connections between the core of downtown and the river.
• Connect multiple riverside parks and cultural sites into an integrated park system.
• Improve bike and walking trail connections to regional trail systems.
• Attract more people downtown for a wide range of recreational and social activities. 
• Increase high-quality recreational open space availability for underserved neighborhoods with high levels of poverty and lack of access to quality park space.
• Stimulate economic reinvestment and development opportunities within the city’s downtown by reactivating the area as a cultural and recreational anchor. 
• Activate the river as a corridor for water sports.  

• A 1.06-mile section of the Scioto River was returned to a free-flowing state after removal of a low head dam and 1,000 ft of deteriorating floodwall and concrete revetment. The streambed was regraded to include multiple 4-6 ft riffles (shallow water quickly moving over rocks), several 14-16 ft pools (a section of deep, slowly moving water), and glides (transitions between a riffle and a pool) in order to improve the riverine habitat. Removal of the dam and floodwall resulted in 33 acres of reclaimed open space within a dense urban environment. 
• The renovated site has 82% permeable and 18% impermeable surfaces, as compared to 49% permeable and 51% impermeable pre-construction. Paths are constructed of slab concrete as well as red and black brick.
• The existing Civic Center Drive, which runs along the river, was reduced from 5 lanes to 2, reducing speeds and traffic. There are also new crosswalks, a widened pedestrian walkway, and 3 acres of newly created green space along the river. 
• Approximately 173,000 plants representing 55 species were planted on site, 77% of which are native including 38 species and varieties of trees, 13 shrubs, and 20 grasses and sedges. 6 years after planting, 115  plant species were observed on the site. Key habitat-creating species include: buttonbush (Cephalanthus occidentalis), fragrant sumac (Rhus aromatica), maple leaf viburnum (Viburnum acerifolium), Virginia wild rye (Elymus virginicus), and riverbank tussock sedge (Carex emory). 
• 153 solar panels (totaling 703 sf) are located on a restaurant in the park.
• 1.5 miles of new multi-use trails (lengthening the existing Scioto Trail), connect to Olentangy River Trail and the Downtown Connector Trail and also improve connections between sections of the Ohio to Erie Trail. These trails connect 7 previously unconnected city parks and memorial spaces. Trail connections provide improved access to open space and amenities for nearby Franklinton, a neighborhood which has historically experienced high poverty and unemployment levels. 
• A 33,000-sf civic plaza is constructed of slab concrete accented with pavers of bluestone, cobble, and brick. The plaza includes an interactive water feature, a 200-seat restaurant with patio, and precast concrete planter benches with a leaf shape. A 4,400-sf bandshell faces the plaza across a turf and concrete amphitheater. 
• The 15,000-sf interactive water feature shoots jets of water 75 ft into the air. It has 5 stainless-steel halo structures with 1,100 fog nozzles and 1,079 ground level spray nozzles arranged in 24 rows.
• A 1,140-ft-long stone paved promenade along Civic Center Drive features a stone colonnade with swings, planter gardens, water canals, and table seating for games of chess. At the center of the promenade there is a specially designed fountain made of bronze fish. The fish was styled after a river redhorse, which was once populous in the river but is no longer found in the area as it is intolerant of pollution. A prow-shaped structure provides a scenic overlook of the river.   
• Increased access for paddle sports was created through new water entry points and 2 new kayak/canoe rental businesses. 

• The Scioto Greenways project started off with the breach of the Main St. low head dam, requiring that 4,500 mussels (representing 8 native species including 1 state threatened and 1 species of concern) be relocated before lower water levels and colder temperatures threatened their survival. Due to permit issues related to a federal government shutdown in 2013, this rescue had to be compressed into several days rather than the previously planned 6 weeks, which required a large volunteer contingent, including members of design team, to complete. Designers should carefully consider the potential for disruptions to the construction schedule in scenarios related to protecting wildlife and aquatic life, as it is not something the construction manager is likely to consider.
• In the 2 years between the initial bathymetric survey made to design and calculate bank toe reinforcement quantities and the start of construction, it was determined by test excavations that a sound river bottom was 1-4 ft below the surveyed river bottom grades due to water dynamics moving sediment. This difference required a revised embankment detail and a significant amount of additional fill. Future projects of this type should set a budget and schedule that allows for adequate response to a constantly evolving natural system.
• During the design phase of the Greenways, a test plot was created at nearby Scioto Audubon Metropark in order to evaluate bankside plants intended to be used for the final project. This plot was monitored for a full year and demonstrated that many of the plants intended for the site were not viable options. The final planting list for the Greenways reflected a complete change in the planting palette to more robust (though less diverse) selections.
• Initial herbaceous plantings along the newly created riverbank were attractive to a large number of Canadian geese for nesting and feeding, causing significant damage and increased need for maintenance to clean up droppings. This was ameliorated by replanting areas with woody vegetation less attractive to geese. This issue made it clear that there is a need to clearly plan and budget for temporary animal control, as well as clearly define who is fiscally responsible for this control to prevent contention between the owner and contractor. 
• Young tree plantings were persistently harvested by a beaver for a downstream lodge. Ultimately heavy tree guards were installed to prevent further loss, which was not an aesthetically pleasing solution. These guards should be able to be removed when the trees reach 10-in caliper as the beavers will likely lose interest. 
• Scioto Mile had numerous in-kind donations for products, materials, and equipment. This public-private partnership fundraising effort required extra coordination, quality control review, additional design and engineering services, and additional construction hard costs. Sometimes firms are reluctant to apply stringent expectations for donated materials regarding quality control, deadlines for provision, and precise materials and methods. The landscape architect worked with the owner and construction manager to establish agreements early on in the design process in order to set and enforce these expectations which allowed them to successfully maintain design intent and quality. 
• The landscape architects’ original design intent was to have a more robust riparian habitat with greater biodiversity. Though the owner agreed with the concept, some key stakeholders desired a more manicured appearance. This required a more restricted plant palette and increased turf areas. Further, though the maintenance requirements and visual appearance of this type of plant material were clearly conveyed and were accepted by city administrators and staff engaged in early presentations and meetings, these expectations were not conveyed to the city maintenance crews and volunteers who care for the naturalized areas. When the sites opened, those maintaining the landscape applied standard practices used for all city parks including excessive spraying for weed control, which destroyed some of the young native plants and caused complications for some plant warranties. Though the landscape architects later did a walkthrough with staff to help them understand the requirements of the natural planting maintenance needs, it is clear that influential maintenance supervisors and staff should be involved in early design process meetings where goals and objectives are defined.    

Scioto Mile
Blossom Grate Support, Prow Guardrail: Stewart Iron Works
Granite Street Curbs: Polycore
Halo and Blossom Fountain Metal Structures: Stewart Ironworks
Halo and Blossom Fountain Fog Poles: Fantastic Fountains/Action Consulting Engineers
Halo and Blossom Fountain Lighting: Crystal Fountains Lighting
Blossom Fountain Vibration Control: Kinetics Sound Control
Blossom Fountain Grating: Hendrick Screen
Café Misc. Metals, Roof Screen Wall, Columns: Wanner Metalworx
Sign Precast Base: Wausau Tile
Promenade and Canal Fountain, Pavilion Granite: Architectural Specialties Inc.
Bronze Fish Sculpture: Spohn Associates/ Deggingers’ Foundry
Promenade Pavers: Endicott Brick - Manganese; Beldon Brick – Modified Garnet Blend, Rose
Park Pavers: Beldon Brick, 740A; Kerfed, 530A
Granite Cobbles: Architectural Specialties LTD – Golden Mist, Forbidden Black and Mountain White from China
Trellis Swings on Promenade, Checkerboard Table: Landscape Forms 
Light Fixtures: Daybrite, Linear, Hess America, KIM, McPhilben, Holophane, BEGA, I-Light Technologies, Lumec, and Schreder
Photovoltaic System: Siemens

Scioto Greenways
Site Furnishings: Landscape Forms
Irrigation: Rain Bird

Project Team

Scioto Mile
Lead Designer, Landscape Architect: MKSK
Civil: EMH&T
Transportation: Trans Associates
Structural: SMBH
Geotechnical: BBC&M
Electrical: Dynamix
Environmental: Williams Creek (River Edge Restoration)
Lighting: HLB
Graphics: Kolar Design
Architecture: HKI – Architect of Record
Architecture: 360
Fountain: Waterworx
Audio-visual for Water Features: Live Technologies
Balustrade: Schooley Caldwell
Soils/Testing: Lee Testing
Artist: Darren Meyers

Scioto Greenways
Landscape Architect: MKSK 
Owner: City of Columbus 
Project Engineer (Lead Consultant, Hydraulic and Civil): Stantec Consulting, Inc. 
Environmental and Geotechnical: Resource International
Cultural Investigations: ASC
Structural Engineer: SMBH
Electrical Engineer: Korda/Nemeth Engineering
Construction Manager: Messer Construction Company
Client and Project Developer: Columbus Downtown Development Corporation (CDDC)

Role of the Landscape Architect

The landscape architect led a multidisciplinary team in the design, documentation and implementation of the Scioto Mile. They were responsible for design oversight as well as design of all non-vehicular hardscape features and plantings. They coordinated construction observation and submission of all review materials. They also supported fundraising activities, which accounted for approximately 50% of the overall project cost and included preparation of graphics and exhibits of concepts and naming opportunities for private and corporate donors.  

For Scioto Greenways, the landscape architect was contracted under the project engineer for idea creation and oversight of all design. They participated in almost all project meetings, presentations, and project functions. They worked collaboratively with the project engineer to determine recommended embankment strategies and designs to maintain proper flood control, set aesthetic goals, and establish the park environment on the riverbank. They also provided construction observation and preparation of review submittals for all site improvements above the waterline.