Overview

The proposed St. Andrews Stream Stabilization Project, approximately 2,500 feet in length, will take place along an unnamed tributary of Greens Mill Run.  Beginning near the commercial parking lots of Plaza Azteca (restaurant) and Kids Street Urgent Care, the tributary continues to flow North toward a culvert under Fairlane Road (project area map below).

The site’s drainage area is approximately 128 acres in size, occupied by predominantly urban and suburban land-uses with 40% impervious (hard surface) cover. After a complete site assessment of the project area, KCI, the City’s engineering consultant, reported the site as having extensive and severe bank erosion as well as active channel instability.

Prioritization

The severe bank erosion along the project channel has resulted in numerous trees falling into the stream and lateral migration of the actively unstable stream channel.  These issues are compromising the integrity of adjacent infrastructure and residential structures.

Public & Private Infrastructure Impacts:

As noted above, the lateral migration of the actively unstable stream channel threatens numerous elements of public and private infrastructure.  These include storm drains, sewer, electrical, and telecommunications facilities. The unstable channel is also threatening the structural integrity of adjacent multi-family residential buildings and numerous sheds and garages near the streambanks.

Private Property Impacts:

• Permanent Drainage Easements and Temporary Construction Easements will be required along the private properties throughout the limits of the stabilization project. 
• Some tree removal and grading will be required.
• Private fencing and structures may require removal or relocation.

Project Description

Streambank and streambed stabilization in this area are critical to the protection of the surrounding infrastructure. Reducing streambank erosion will also reduce harmful sediment pollution downstream to Greens Mills Run. These issues will be addressed by:

• Constructing low elevation floodplain benches.
• Constructing a stable channel by implementing new channel dimensions that are area appropriate for the incoming flows.
• Increasing the channel bed elevation within parts of the channel restoration to put utility crossings back underground as intended.
• Stabilizing graded and disturbed areas with natural fiber material and native plantings. 
• Planting live stakes, herbaceous and woody shrubs, trees, and appropriate seeding that are suitable for a shaded tree canopy and occasionally wet stream-side conditions. 
• Limiting grading and stream restoration activities to the unstable areas to minimize disturbance.

Frequently Asked Questions

Stormwater

1. Private properties in this area currently have drainage or erosion issues. What can the city do to help with these issues? This project is being undertaken specifically for this reason. The primary purpose of this effort is to utilize stream restoration techniques, such as bio-engineered reinforcement structures and natural channel design, to design and implement a new channel with stable stream bed and banks. The new stable channel will prevent the process of erosion and future channel migration from threatening public infrastructure and private property.

Traffic Controls, Pedestrian Access, General Construction

1. Will this project limit my access to my property? The contractor will be required to maintain access to all properties. The construction limits of disturbance for this project will be along the stream in the rear yards of the properties.
2. How will my questions/concerns be addressed and communicated? A summary of questions and answers received by mail, phone, email, or at the public meetings will be posted here on the project webpage. The project email address is [email protected].
3. Will the City provide us with points of contact should any questions or concerns come up during construction? Yes. Points of contact for the construction phase will be provided to the public.
4. When is the project proposed to take place and what is the timeline for completion? The intent is to have funding in place to begin construction during Summer 2025. Construction is expected to take 12 months.
5. During construction, will the contractor be held to working hours? These requirements will be outlined in the contract specifications. Some exceptions are allowed for working weekends or extended hours for certain types of work, such as facilitating utility services or property access. The contractor will be required to have written approval from the city to utilize time outside of normal work hours.
6. Will trees/shrubs be removed and replaced where there are screening and buffer requirements or needs? The City will plant vegetation on private property in an effort to restore screening and buffers. Vegetation size, location, and species may be coordinated with the property owner.
7. Will any private fences be removed or relocated? The design will limit the impact to private property as much as possible. Where fences must be removed, temporary fencing can be coordinated with the property owner during construction and permanent fencing replaced in-kind after construction is complete.
8. Will any private sheds be removed or relocated? The design will limit the impact to private property as much as possible. However, sheds located in the permanent maintenance easement will need to be relocated and sheds located in the temporary construction easement will need to be relocated during the period of construction unless other arrangements are made with the property owner.
9. Will there be tree protection requirements? Yes, the contract will have tree protection fencing for trees in the project area that are intended to remain.

Water, Sewer, Gas, & Electric Utilities

1. Has Greenville Utilities Commission (GUC) been involved in the plan review process? Yes. GUC is reviewing the plans and is evaluating and coordinating all needed improvements to water, sewer, gas, and electric systems in the project area.
2. Will there be service interruptions and how will we be notified? Service interruptions are not anticipated with this project. If interruptions are to occur, citizens are normally notified twice (by contractor and by GUC). GUC notifies 48 hours in advance, when possible, either in person or by using door hangers.
3. Will there be bypass pumping? Will the pumps be silent? GUC requires critically silenced pumps near residences. For this project, no bypass pumping for sewer is anticipated. Any required erosion control pumps would also be specified as "silent."