LOWER WICOMICO RIVER MAINTENANCE DREDGING

Description

Amendment 0001 issued on July 20, 2022 Amendment 0002 issued on August 09, 2022 Amendment 0003 issued on August 22 2022 Lower Wicomico River Maintenance Dredging at Wicomico County, MD This proposed procurement is a Competitive Invitation for Bid (IFB); NAICS 237990 �Other Heavy and Civil Engineering Construction� with a size standard of $39,500,000.00. Total 100% Small Business Set-aside. This project is to include the hydraulic dredging the lower half of the Wicomico River to its authorized depth of 14 feet (plus one foot of allowable over depth). Approximately 120,000 cubic yards of silty material, with small pockets of sandy material, are to be dredged. Placement of material via pipeline will be utilized. Pipeline distance will be, on average, 8 miles, with a maximum pumping distance of 14 miles. The pipeline will travel through the Wicomico River and over land (approximately 4 miles) to reach the placement site. The pipeline will be placed atop the existing berm at the WMA impoundment and a diffuser shall be used at multiple locations to place the material at a lower velocity into the placement site. The outflow of the pipeline shall be moved across the project placement areas to achieve the desired elevation. As such, careful attention to the prescribed elevation in placing the material is critical to the success of the project. Approximately 70 acres of land will be restored. Due to the location of the placement site being surrounded by water and the WMA impoundment, minimal land access is available with little to no access for heavy equipment from the land side of the project placement site. Wetland restoration is meant to increase migratory bird nesting habitat. To ensure the restoration goals are met the placement location shall also include placing straw bales as natural containment around the southern end of the placement site. The straw bales are to act as containment for dredged material placed for wetland restoration and increasing migratory bird nesting habitat. Approximately 11,000 strawbales will be used stacked two high with an additional single stacked row at the interior of the placement site to provide proper containment of the dredged material. Tidal ditch plugs shall be constructed in areas of high erosion or open water. Approximately 20 ditch plugs of varying size are to be constructed. After dredged material placement, vegetation will be planted to restore the wetland. Planting of vegetation will occur over the two growing seasons post dredged material placement. Vegetation will be Spartina patens and Distichlis spicata, and possibly a smaller amount of Panicum. Vegetation the first growing season may require aerial seeding, based on consolidation of the dredged material. Vegetation the first growing season shall also require the exterior edge only to be hand planted to provide stabilization, with interior planting occurring the second growing season once material has consolidated.