Neabsco Creek Dredging Complete

Last spring the U.S. Coast Guard declared Neabsco Creek too shallow to safely navigate by motorized watercraft and closed the channel. During their 2018 survey the Coast Guard found that Neabsco Creek depth was less than five feet deep, the authorized depth. Neabsco Creek has three privately-owned marinas with about 1,000 recreational boats as well as a water-rescue boat belonging to a Prince William County volunteer fire department. The marinas also house a boat lift, used by larger vessels from across the region, and the only marine gas station in the region open 365 days a year.

The Coast Guard’s warning signs reading “Danger Shoal” threatened the continued use of Neabsco Creek for boating. The only way to restore the waterway was to dredge. It was estimated that it would cost $750,000 to $1,000,000 to dredge out what had been the navigable portion of Neabsco Creek. A coalition of marina owners and recreational boaters turned to Prince William County for help. Recreational boating is important to Prince William County not only for its economic contribution, but also for the quality of life.

The Board of County Supervisors allocated up to $750,000 grant funding to dredge the creek, and the county also obtained a grant from the Virginia Port Authority for up to $250,000. The extra funds went towards the dredging of the channel, and allowed the County to dredge the creek to six feet and a 50-foot-wide channel for boaters to come in and out of the marinas. In addition to the dredging funded by the county, local marina owners got together, formed a partnership and contributed approximately $150,000 to dredge their marinas at the same time the channel was being dredged.

The bottom of creeks routinely fill with sand and silt, gradually filling in the channel until it is no long safe to navigate. This is called sedimentation and is a natural process, but it can be exacerbated by poor storm water management practices and impervious ground cover which increases the volume and velocity of runoff.

Sediment can come from soil erosion or from the decomposition of plants and animals. Wind, water and ice help carry these particles to rivers, lakes and stream. According to the EPA natural erosion produces 30% of the sediment in our streams and lakes, erosion from human use of land accounts for the remaining 70% - one of the most significant sediment releases come from construction activities, including relatively minor home-building projects such as landscape projects room additions and swimming pools.

For longer term solutions and to reduce the need for dredging in the future, the sources of sediment need to be reduced. The Watershed Management Branch of the County’s Public Works Department, engaged a watershed study in the five northernmost sub-sheds of the Neabsco Creek watershed. The purpose of the study was to assess the condition of existing stormwater management facilities and streams. In addition to identifying existing problems, they also identified opportunities to reduce sediment flow in the future through reforestation and land conversion projects. By restoring natural functions to land that has been affected by development, the County can improve local waterways and reduce sediment flow in the future. Now that Neabsco Creek has been dredged we need to implement practices to prevent sedimentation in the future.