Avoidance and Minimization Measures¶

Design¶

• 2:1 side slopes -- Shoulder slopes were reduced from 6:1 (design standard) to 2:1 where feasible and practicable to avoid or minimize jurisdictional impacts.

• 3:1 side slopes -- Shoulder slopes were reduced from 6:1 (design standard) to 3:1 where feasible and practicable to avoid or minimize jurisdictional impacts.

• 4:1 side slopes -- Shoulder slopes were reduced from 6:1 (design standard) to 4:1 where feasible and practicable to avoid or minimize jurisdictional impacts.

• Clearing Limits Reduced -- Clearing limits have been reduced from design standards (typically to ROW limits) where possible in jurisdictional areas.

• Median widths reduced -- Median widths were reduced from the standard XX ft to XX ft to reduce the overall roadway footprint and resulting jurisdictional impacts.

Hydrology and Hydraulics¶

• Rip Rap Reduced -- Rip rap pads were reduced where possible to minimize jurisdictional impacts. Rip rap pads in the following locations (include station numbers) were reduced from the standard XX sqft to XX sqft.

• Culverts and Pipes Appropriately Sized -- Culverts and pipes have been sized to provide the best hydrologic and hydraulic connection. The Project is being designed to meet all requirements set forth by South Carolina Department of Transportation (SCDOT),AASHTO, FHWA, and FEMA. All design criteria for storm drainage, culverts, and bridges are based on SCDOT's "Requirements for Hydraulic Design Studies" dated May 26, 2009. The SCDOT "Requirements for Hydraulic Design Studies" dated May 26, 2009 meet or exceed all recommendations by AASHTO, FHWA, and FEMA. If requested, a verification memo stamped by the hydraulic design engineer will be provided after all hydraulic studies for this project have been completed.

• Closed drainage system installed -- A closed drainage system will be installed on the proposed bridge to prevent stormwater from being directly discharged into jurisdictional waters.

• Stormwater Diverted - A closed drainage system is not feasible for the proposed bridge, so scuppers are necessary to remove stormwater from the travel lanes. Scuppers placement will avoid discharging directly over {waterbody}

• Scuppers Minimized - A closed drainage system is not feasible for the proposed bridge, so scuppers are necessary to remove stormwater from the travel lanes. Scuppers placement has been minimized to the great extent practicable.

• Bridge Vertical Clearance Increased -- The low chord of the bridge has been raised to improve hydrologic and hydraulic connection. The existing bridge has XX feet vertical clearance while the proposed bridge will have XX feet of clearance. The Project is being designed to meet all requirements set forth by South Carolina Department of Transportation (SCDOT),AASHTO, FHWA, and FEMA. All design criteria for storm drainage, culverts, and bridges are based on SCDOT's "Requirements for Hydraulic Design Studies" dated May 26, 2009. The SCDOT "Requirements for Hydraulic Design Studies" dated May 26, 2009 meet or exceed all recommendations by AASHTO, FHWA, and FEMA. If requested, a verification memo stamped by the hydraulic design engineer will be provided after all hydraulic studies for this project have been completed.

Structures¶

• Close and Detour Proposed -- The existing bridge will be closed and the proposed bridge will be replaced on alignment within the existing footprint to minimize impacts.

• Bridge Span Increased -- The existing XX ft bridge will be replaced with a XX ft bridge to reduce impacts and improve hydrology.

• Bridge Spans Waterbody -- The proposed bridge has been designed to span {waterbody} to reduce impacts and improve hydrology.

• Bridge crosses perpendicular to the waterbody -- The proposed bridge crosses perpendicular to {waterbody} which [avoids/minimizes] jurisdictional impacts and improves hydrology.

• Narrowest point of waterbody crossed -- The proposed bridge crosses {waterbody} at the narrowest point.

• Culverts bottoms buried -- Culverts will be embedded to allow a natural stream bottom to reestablish itself and promote fish passage.

• Existing piles removed -- Existing piles will be fully removed when possible. If they cannot be fully removed, then they will be cut at or below the existing soil surface.

• In Water Bridge bents reduced -- The existing XX in water bents will be replaced with a XX in water bents to reduce impacts and improve hydrology.

Construction¶

• BMPs used -- Construction will entail implementation of construction BMPs contained in 23 CFR 650B and the Department's Supplemental Specification on Seeding and Erosion Control Measures.

• Clean fill material used -- Only clean, non-toxic fill materials will be used to avoid impacting water quality.

• Staging outside of jurisdictional areas -- Construction staging areas will be located in upland areas only.

• Existing fill removed -- XX acres of existing fill will be removed and reestablished to historic elevations.

• Remediation proposed onsite -- provide a description in the narrative of any remediation activities that will occur.

• Innovative construction techniques -- provide a description in the narrative of any proposed innovative construction techniques.

• Clearing, no grubbing -- Vegetation will be cut, but the root ball and surrounding soil will not be disturbed.

Natural Environment¶

• Higher quality wetlands avoided -- Higher quality wetlands were avoided where practicable.

• Essential Fish Habitat impacts minimized - Impacts to EFH sensitive habitats have been minimized. For example -- Alignment shifted to avoid impacts to a small tidal creek or mud flat.

• In water work avoided for spawning - In water work within {waterbody} will be avoided during the months of February to June to minimize impacts to anadromous fish spawning

• BMPs increased for aquatic species -- Additional BMPs will be utilized to prevent impacts to sensitive or protected aquatic species. Provide detail in the narrative. For example double row silt fence, jersey barriers, and netting for bridge deck demo.