City Council

Dowden Area Drainage Evaluation Council Districts 9 Phase Preliminary Engineering Phase Budget Estimate $75,000 Background Water from this drainage basin flows into an existing major ditch system that begins at the shopping center to the north and continues under Old Towne Road to the marsh. The system is constricted under Old Towne Road which leads to flooding of multiple properties and roadways along the primary drainage channel. Old Towne Road is also a major corridor for existing underground utilities. Phase Actions This phase includes field survey, utility location, and stormwater modeling to evaluate options to improve flooding. These options are expected to include adding flow capacity under Old Towne Road, adding storage capacity within the basin, or reducing impervious area. Future Actions Following this phase, the selected plan would require design/permitting and construction funding. PROJECT SUMMARY – 2020  Dupont Wappoo Drainage Design Council Districts 5,7,9,11 Phase Design/Permitting Phase Budget Estimate $225,000 City Share/$90,000 County Share Background The City and Charleston County have collaboratively performed a drainage basin evaluation and plan for the Dupont/Wappoo Watershed from 2017 through 2019. This evaluation recommended a series of 10 projects for short term drainage improvements within the basin. This task is for the first 4 of these recommended improvements, focusing on: the drainage pathway from Orleans Road to the rear of the Citadel Mall; the storage of stormwater in the rear of the Citadel Mall; the drainage way from Dupont to the southern end of the Citadel Mall, and check valves along these systems. Phase Actions This phase includes utility location, design, permitting, completion of construction bid documents and project construction budgets. Future Actions Following this phase, the projects would require construction funding. PROJECT SUMMARY – 2020  ARROW WIND AT EMERALD FOREST DRAINAGE Council Districts 2 Phase Construction Phase Budget Estimate $20,000 Background Intersection holds water into the travel lane following rain events Phase Actions Install a new roadside drainage inlet and modify existing pipe system to drain the low area of the intersection. Future Actions None. PROJECT SUMMARY – 2020  CONCORD ST AT WATERFRONT PARK DRAINAGE Council Districts 1 Phase Construction Phase Budget Estimate $40,000 Background Handicap Parking Space and Access Ramp hold water following rain events. Phase Actions Install new inlets, modify roadside collection system and regrade parking space to mitigate ponding. Future Actions None. PROJECT SUMMARY – 2020  WEIMS CT DRAINAGE Council Districts 8 Phase Construction Phase Budget Estimate $30,000 Background Road holds water following storm events. Road has a small brick arch system that has failed and needs to be restored to improve drainage. Phase Actions Install new inlet manhole and rehabilitate small brick arch lateral back to main arch. Future Actions None. PROJECT SUMMARY – 2020  SHERWOOD FOREST DRAINAGE IMPROVEMENT Council Districts 7 Phase Construction Phase Budget Estimate $50,000 Background Rear yards hold water in the neighborhood. City has previously acquired drainage easement through the area and needs to reconstruct drainage system to improve flood conditions. Phase Actions Remove trees, remove fencing, install drainage swale and pipe. Future Actions None. PROJECT SUMMARY – 2020  CONCORD ST PUMP STATION RETROFIT Council Districts 1,4 Phase Design Phase Budget Estimate $125,000 Background Pump station serving Calhoun East and Market St deep tunnel drainage projects requires updates and pump replacements due to expected service life coming to an end. The system was last updated in the early 2000s. Phase Actions Design, specify, and provide procurement assistance in primary pump, dewatering pump, electrical systems, pump control systems, and space conditioning. Future Actions Procurement Costs for Designed System Retrofits. PROJECT SUMMARY – 2020  PAWPAW ST DRAINAGE Council Districts 11 Phase Design Phase Budget Estimate $10,000 Background Woodland Shores area has a system of disconnected drainage pathways. The City and County are currently collaborating to improve the drainage outfall that runs through the Muni Golf Course and out to the Stono. Phase Actions Survey and plat drainage easements for dedication on the ditch system to the north of Pawpaw St to connect/maintain this component of the system into the improved outfall to improve neighborhood drainage. Future Actions None. PROJECT SUMMARY – 2020  WAGNER TERRACE REHABILITATION Council Districts 3,6 Phase Construction Phase Budget Estimate $50,000 Background The Wagner Terrace neighborhood has a large network of older drainage pipes that are heavily impacted by tree root blockages that can create road flooding. Phase Actions Remove root blockages and clean pipe systems in the neighborhood. Future Actions None. PROJECT SUMMARY – 2020  FORT ROYAL DRAINAGE IMPROVEMENT Council Districts 9 Phase Construction Phase Budget Estimate $350,000 Background Wespanee experiences road and property flooding and has an undersized outfall system. The project has previously been surveyed and designed. Phase Actions Construct improvements to outfall system and improve upstream portion of neighborhood drainage system to connect and realize improvements from the outfall. Future Actions None. PROJECT SUMMARY – 2020  MUELLER DRAINAGE IMPROVEMENT Council Districts 9 Phase Construction Phase Budget Estimate $20,000 Background The Mueller/Charlyn area has rear yard flooding. A drainage easement exists in the neighborhood but does not have an existing drainage conveyance. This work would remove the sheds and other obstructions from the easement to create an open drainage swale. Phase Actions Remove sheds, fences, and other obstructions to drainage and install open drainage swale in the rear of properties. Future Actions None. PROJECT SUMMARY – 2020  HARBORSUN DITCH STABILIZATION Council Districts 6,12 Phase Design/Construction Phase Budget Estimate $100,000 Background The outfall canal for the Westchester neighborhood including Folly Road and Secessionville Road flows under Harborsun Road. Past storm events have caused erosion of the canal toward a residential structure. Phase Actions Design bank stabilization; remove vegetation and install bank stabilization. Future Actions None. PROJECT SUMMARY – 2020  SAVANNAH HIGHWAY SIDEWALK DRAINAGE IMPROVEMENT Council Districts 11 Phase Construction Phase Budget Estimate $150,000 Background The sidewalk and properties along the south side of Savannah Highway in Byrnes Downs experience flooding following rain events and have erosion issues from the HWY 17 embankment. Phase Actions Install bank stabilization and level portions of the sidewalk to reduce ponding water issues along the sidewalk following storm events. Future Actions None. PROJECT SUMMARY – 2020  Belfast Roadside Drainage Improvement Council Districts 11 Phase Construction Phase Budget Estimate $10,000 Background The roadside drainage is comprised of asphalt swales that do not connect to the outfall system at the back of Belfast Road until significant ponding exists on the road and properties. Phase Actions Driveway culverts and front yard ditches to convey water to the outfall system. Future Actions None. PROJECT SUMMARY – 2020  Wespanee Drainage Evaluation Council Districts 9 Phase Design Phase Budget Estimate $50,000 Background The area currently receives flooding on a low lying quadrant of properties. The local pipe networks need to be evaluated to determine if they can be modified to provide drainage of the area. Phase Actions Survey pipe network and develop stormwater model for potential capacity and grade improvements. Future Actions Following this phase the project would require construction funding. PROJECT SUMMARY – 2020 Project Budget Description Belfast Roadside Drainage Improvement $ 10,000 Installation of Driveway Pipes and Roadside Ditch to Connect Road Drainage to Existing Outfall to Relieve Road Flooding Concord St at Waterfront Park Handicap Drainage $ 40,000 Modification to Paving and Inlets to Relieve Road/Ramp Ponding Concord St Pump Station Retrofit Design $ 125,000 Design of Pumps/Electrical/Control Systems/Water Quality for Needed Pump Station Retrofit of 20+ Year Old Facility Dowden Area Drainage Evaluation $ 75,000 Drainage Model and Improvement Option Evaluation for Property/Road Flooding Dupont Wappoo Drainage Design $ 225,000 Design/Permitting of 4 Improvement Projects Identified in Dupont Wappoo Evaluation Emerald Forest at Arrow Wind Box Installation $ 20,000 Installation of New Stormwater Inlet to Relieve Road/Sidewalk Ponding Fort Royal Area Drainage Improvement $ 350,000 Installation of Modified Outfall System and Upgrade to Neighborhood Conveyance System to Relieve Property and Road Flooding Harborsun Ditch Stabilization $ 100,000 Design and Construction to Repair and Stabilize a Drainage Canal Bank in Vicinity of a Residential Structure Mueller Drainage Improvement $ 20,000 Installation of Rear Yard Drainage Swale on Existing Easement to Relieve Rear Yard Flooding Pawpaw St Drainage Improvement $ 10,000 Survey for Dedication and Restoration of Drainage Easement for Neighborhood Rear Lot System Savannah Hwy Sidewalk Drainage Improvement $ 150,000 Design/Permitting/Construction of Shoulder Stabilization and Sidewalk Drainage Improvements to Relieve Sidewalk and Front Yard Flooding Sherwood Forest Drainage Improvement $ 50,000 Installation of Rear Yard Drainage Swale on Acquired Easements to Relieve Yard Flooding Wagner Terrace Pipe Rehabilitation $ 50,000 Root Removal from Roadside Pipe System to Relieve Road Flooding Weims Ct Drainage Improvement $ 30,000 Restoration of Short Brick Arch Segment and Addition of New Inlet to Relieve Road Flooding Wespanee Drainage Evaluation $ 50,000 Evaluation of Improvement Options to Drainage System for Property Flooding Rivers Point Row $ 43,220 Completed Project for Roadside Pipe Restoration from Structurally Failed Pipe Lord Calvert CO #1 $ 19,922 Roadside Drainage Improvement Project to Relieve Road and Property Flooding Total $ 1,368,142 Project Budget Description Belfast Roadside Drainage Improvement $ 10,000 Installation of Driveway Pipes and Roadside Ditch to Connect Road Drainage to Existing Outfall to Relieve Road Flooding Concord St at Waterfront Park Handicap Drainage $ 40,000 Modification to Paving and Inlets to Relieve Road/Ramp Ponding Concord St Pump Station Retrofit Design $ 125,000 Design of Pumps/Electrical/Control Systems/Water Quality for Needed Pump Station Retrofit of 20+ Year Old Facility Dowden Area Drainage Evaluation $ 75,000 Drainage Model and Improvement Option Evaluation for Property/Road Flooding Dupont Wappoo Drainage Design $ 225,000 Design/Permitting of 4 Improvement Projects Identified in Dupont Wappoo Evaluation Emerald Forest at Arrow Wind Box Installation $ 20,000 Installation of New Stormwater Inlet to Relieve Road/Sidewalk Ponding Fort Royal Area Drainage Improvement $ 350,000 Installation of Modified Outfall System and Upgrade to Neighborhood Conveyance System to Relieve Property and Road Flooding Harborsun Ditch Stabilization $ 100,000 Design and Construction to Repair and Stabilize a Drainage Canal Bank in Vicinity of a Residential Structure Mueller Drainage Improvement $ 20,000 Installation of Rear Yard Drainage Swale on Existing Easement to Relieve Rear Yard Flooding Pawpaw St Drainage Improvement $ 10,000 Survey for Dedication and Restoration of Drainage Easement for Neighborhood Rear Lot System Savannah Hwy Sidewalk Drainage Improvement $ 150,000 Design/Permitting/Construction of Shoulder Stabilization and Sidewalk Drainage Improvements to Relieve Sidewalk and Front Yard Flooding Sherwood Forest Drainage Improvement $ 50,000 Installation of Rear Yard Drainage Swale on Acquired Easements to Relieve Yard Flooding Wagner Terrace Pipe Rehabilitation $ 50,000 Root Removal from Roadside Pipe System to Relieve Road Flooding Weims Ct Drainage Improvement $ 30,000 Restoration of Short Brick Arch Segment and Addition of New Inlet to Relieve Road Flooding Wespanee Drainage Evaluation $ 50,000 Evaluation of Improvement Options to Drainage System for Property Flooding Rivers Point Row $ 43,220 Completed Project for Roadside Pipe Restoration from Structurally Failed Pipe Lord Calvert CO #1 $ 19,922 Roadside Drainage Improvement Project to Relieve Road and Property Flooding Total $ 1,368,142 Ready to Construct $ 130,000 Ready to Design $ 350,000 Previously Allocated $ 63,142