The Lowline will not become a world class park overnight. This has been a long process to the Conceptual Design and we have a lot of work to do until this park becomes reality. But we can take the steps now to work towards our goal. Let's take the first step together.
**Disclaimer: This phasing strategy is meant to be a guide and is not a final document. Phases may take shorter or longer time depending on many factors. Please contact us if you have any specific questions.
Also please see "How did we get to these numbers?" for more information.
The Friends of the Lowcountry Lowline and the City of Charleston have agreed to deliver interim improvements in the project area. A simple multi-use pathway and some fully-completed portions of the Lowline already exist and can be expanded. This phase proposes two types of interim improvements: 1) infrastructure like simple paths and sports courts, and 2) programming that gets people out using the space immediately. Programming may include clean-ups, site tours, art installations, painting, fitness classes, outdoor markets, etc. Some of these events are already happening and provide great benefit. But we need your help. Donate today.
This is the perfect spot to get started. This phase involves a large central park, parking areas below I-26 and various related public street and stormwater improvements. It also includes the City’s affordable housing site and connection the East Side via the Cooper River Bridge Redevelopment Area (CRBRA). We will be able to provide a usable pathway, add fun and inclusive programming, and set the stage for what this park can be when fully completed. This touches on mobility, stormwater, programming and horticulture: it is a great starting point.
Estimated Construction Cost: $9,030,625.00
Progress: Pre-Design
Estimated Start Time for Construction: 2022
This phase involves Lowline improvements on City owned properties, several blocks of dense urban mixed-use development, The City will work with private developers to
identify incentives, such as using parts of the Lowline for stormwater management, in exchange for them to pay for and construct parts of the Lowline. The area will include
three mid-block crossings, one of which is an SCDOT street.
Estimated Construction Cost: $3,512,500.00
Progress: Pre-Design
Estimated Start Time for Construction: 2023
This phase will leverage the funded improvements at King Street and Huger Street to develop a large water management open space system. This idea was recommended by the Dutch Dialogues Charleston report as a way to manage flooding on the peninsula. Improvements here will also include multi-purpose courts, the DIY skate park known as the "Bridge Spot", a mid-block crossing at Huger Street, and fully improved pathway conditions for the Lowline up to Grove Street. The mid-block crossing at Huger Street must be coordinated with other improvements on that corridor.
Estimated Construction Cost: $7,884,375.00
Progress: Pre-Design
Estimated Start Time for Construction: 2023
This area of the Lowline is privately-owned. Delivery of the Lowline will be through negotiations with individual properties for access easements, maintenance agreements and other legally-binding arrangements to ensure a high quality of design and public access to extend the Lowline through the middle of the block in these areas. Relevant review bodies and City staff will use the Lowline Design Guidelines to direct the design of physical improvements in this area. Any properties that are fenced off or otherwise privatized will be opened up, and, if deemed necessary by City staff, improved to be suitable for public access and use. City staff will develop a strategy to require or otherwise ensure the construction of essential mid-block pedestrian crossings in this location.
Estimated Construction Cost: $2,353,125.00
Estimated Start Time for Construction: 2024
*Rendering Courtesy of City of Charleston Design Division, 2020
Improvements from Grove Street to San Souci Street. This phase will involve the following: 1) complete the multi-use path to its fullest in this area, 2) installing as many stormwater storage areas and multipurpose courts beneath I-26 as possible, 3) extend the Service Street north of Brigade Street, 4) create neighborhood pocket parks at the end of each intersecting street, 4) install mid-block crossings, and 5) upgrade the outdoor market and surroundings to a long-term condition.
Estimated Construction Cost: $8,923,437.00
Estimated Start Time for Construction: 2024
Redevelop the Parks Department and build the portion of the Lowline that runs through it using a public-private partnership (PPP). The PPP will take advantage of private investment to deliver the Lowline and other public benefits. Private development will be attracted to the site given its development capacity (available space, prime location, zoning, etc.) (while the Parks Department may operate more efficiently from a different location). Switch the development area with the path area, rerouting the path to connect to the intersection of Morrison Drive, Meeting Street and Mount Pleasant Streets. Leverage funding associated with the planned Lowcountry Rapid Transit project as part of a transit-oriented development.
To learn more about the Lowcountry Rapid Transit and how it will compliment the Lowcountry Lowline, please visit their website: https://lowcountryrapidtransit.com/
Estimated Construction Cost: $1,378,125.00
Estimated Start Time for Construction: 2024
Using another public-private partnership (PPP), retrofit the existing bus mall to be part of the Lowline by getting the private sector involved. Incentivize the private sector to construct and lease ground level commercial space in the existing parking garage at this location, perhaps in exchange for making physical improvements (converting the bus mall to the Lowline and constructing its relevant mid-block crossings).
Estimated Construction Cost: $1,409,375.00
Estimated Start Time for Construction: 2025
Construct mid-block crossings on John Street and Hutson Street. Convert the service alley behind Hotel Bennet to become a more pedestrian-oreinted space leading from Hutson Alley to Marion Square.
Estimated Construction Cost: $806.250.00
Estimated Start Time for Construction: 2025
The Opinion of Probable Construction Costs above is a limited analysis by Kimley-Horn based on initial concepts depicted in the Lowline Conceptual Design Document prepared by DesignWorks dated October 2019. The cost estimates are prepared by phase in accordance with the phasing outlined in the Lowcountry Lowline Design Guidelines & Implementation Framework (Working Draft July 2020). Kimley-Horn has utilized typical construction cost unit rates based on similar projects and adjusted for current Charleston, SC unit rate data at the time of this publication. All unit rates are variable and can be affected by many factors including the current pandemic event being felt worldwide.
Several assumptions have been made in the process of determining estimated construction costs. One specific assumption is that 2 feet of undercut for unsuitable soils will be needed, and therefore 2 feet of fill has been used for the grading line item. This depth is an estimate and further discussion on unsuitable soils and the amount of undercut needed will be required. A value engineering technique can include the capping of unsuitable soils; this may be a possibility to be explored further and can have a positive effect on cost.
Additionally, here is a brief description or explanation of the information used to arrive at the cost for line items in the cost estimate.
Field offices – An office for each of 3 sections is budgeted based on level of construction effort, construction time, and closeout. A cost savings could be realized by combining phases, combining section effort, or strategically placing a field office near two sections.
Contaminated Soil – As previously mentioned, the means and methods to deal with soil
contamination after years of pathway/corridor maintenance can affect construction costs and should be evaluated after testing is completed and recommendations are offered by a
Geotechnical consultant. Complete removal and replacement of select fill can be a costly
effort. Other means may be available in various sections.
Surfacing – A variety of materials could be used as the surface for the Lowline path in each section. For the purposes of this estimate a unit price for asphalt has been used.
Storm Drainage – The estimated costs for storm drainage included lump sum costs for
stormwater components that may be provided in the Lowline sections such as underground detention chambers, rain gardens and proprietary water quality devices. A separate line item has been provided for a potential pump.
Utility Duct Bank - Some existing utilities may require realignment and/or replacement into consolidated duct banks depending on local conditions. A detailed survey is needed prior to the design phase. Budgets defined in the cost analysis are based on similar projects.
Lighting – A lump sum cost has been provided for each section based off estimates for similar projects.
Signing/Marking- The budget is based on a consistent branded signage, marquee, and
pavement marking system throughout with the intent to not “overdo it”.
Erosion control- A budget per section is set based on required BMP’s to control erosion to City and State Standards. Based on other pathway projects this can be managed in subsections. Due to gentle grades it is envisioned that minimal structural and temporary vegetative BMP’s will be required as long as they are maintained in response to predicted and unanticipated storm events. Inlet protection for surrounding street systems will be required.
Landscaping - Landscape and Hardscape budgets can be affected greatly by overall concepts, materials, public/adjacent landowner participation, Lowline sections, etc. It is suggested that a cost approach to this line item be commissioned to involve section landowners in the process. This has been done on similar projects.
Midblock crossings - Mid-block crossing budget is based on effective crossings on similar urban pathway projects and can be affected by level of design. Note, some communities involve landowners in the vicinity to participate and/or cover these costs.
Site Furnishings - Successful pathway projects in urban settings have different levels of site furnishings, many of which are funded through donations and/or covered by the adjacent landowners. Public outreach programs and tours of similar projects may affect the budgets in turn affecting overall cost.
Consulting and Design- Budget based on similar projects in different pathway projects in the southeast. These budgets can vary depending on timing, length of section, permitting
requirements, and final design concepts.
Examples of items not currently detailed in this cost estimate are:
- Security systems throughout the alignment including call boxes, cameras, monitoring
staff, and overall security program.
- Local, state, Federal permit fees and mitigation costs
- Annual Landscape and Hardscape maintenance costs
- Public Parking areas beyond the three specifically described within this document
- Staging areas for events in park areas along pathway
- Pathway Electricity to power lighting, security systems, and provide electrical stations
for events
- Pathway sound system or speaker systems
- Major Utility Relocations
At this time the cost estimate is preliminary, and it will be necessary to revisit in the future.
Unit prices and construction costs may vary, and therefore it is recommended this Opinion of Construction Cost be updated as the Lowline planning and design process progresses and becomes more detailed.
Lowcountry Lowline
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