SDCC is gathering ideas that will provide a long term solution to moving dredge spoils dredged from the Lynnhaven Watershed.
Have an idea? .(JavaScript must be enabled to view this email address) Use “Discuss” link in this post.
Each can be further explored individually if found sufficiently credible:
Option 1 - - Hydraulic dredge to PAHS during summer days only; obviates interference with school and student issues - extends overall project duration to ~ 2 years (8 months) total but would not extend cost; cost savings for mobilization, wetland remediation, shipping/transfer costs, etc.
Option 2 - - Offer Pembroke area homeowners fair market value for their creek front home + 1 time 15 year tax deferral for purchased property within city limits or city rebuilds homes; LBR construction ($500K+), periodic shoaling dredge to maintain barge access (~$60K/year???), $200K for fuel, salaries, and time to barge down river and truck back to origin $820K [cost neutral] working capital
Option 3 - - hydraulic dredge to local sedimentation barge, allow water to drain, manually remove at designated local point
1. acknowledge a long term solution is necessary.
2. eliminate politics from any solution[s].
3. shoot for the best, most flexible “green” solution[s].
The Lynnhaven Boat ramp was chosen as a transfer area where the city claims they will dodge boaters, humans and bridges anytime they need to when transporting waste through this area. If they choose to use an area near a school then operations are predetermined when to close. Since the Lynnhaven Ramp is the “only” location that experiences high winds and currents, why would you put that in the mix with a bridge. Marine motors operate in the harshest environment, saltwater, the first time one brakes down, which way does the barge float, into a family of five in a boat with 130 gallons of gas under their feet or in to a bridge?
Mechanical Dredging Options:
1. Saw Pen Point is a superior site compared to LBR. If you see safety issues as a wash, Saw Pen floats to the top because of it is the less costly alternative. The city can add restrictions such as use for specific months (say October - February) and only every other year, or every third year. That would give private dredging projects time to plan accordingly.
2. Saw Pen could serve the Western Branch, and other sites should be developed to serve the Eastern Branch and Broad/Linkhorn Bays. No one wants trucks lumbering through their neighborhood, but the aforementioned restrictions would lessen the impacts.
Hydraulic Dredging Options:
1. City should buy the S Twin Lake (Greenwich Road across from Hoffman Beverage) from VDOT and place dredged material there by pipeline. This is not a renewable site, so not as desirable as others, and it is located at the cost effective maximum distance from the river.
2. Lake Trashmore has been off limits due to water quality problems. There is plenty of capacity and the lake is in close proximity to the river (both branches). And the city owns the entire lake and surrounding land. Maybe a slug of salt water would help the water quality?
3. Lake Windsor (just east of Trashmore) has some capacity, is totally owned by the city, and the city owns all the surrounding land. Plus it is saline since it connects to the river.
4. Geosynthetic Sausages are large bags made of strong geosynthetic fabric. They range up to 40’ diameter. The dredger pumps directly into the bag (or a manifold serving serving several bags) which acts as a seive to hold the dredged material in while letting the water flow through. This option becomes more cost effective as other alternatives become more costly. You need land to deploy the bags, and there is time required (days, weeks) for the bags to dewater before they are cut and the material trucked to the Whitehurst Pit. There is also the smell problem…....
Combination Hydraulic and Mechanical:
A REAL long term solution, IMHO, is to hydraulically dredge material into Lake Trashmore. When additional capacity is needed, then excavate and truckhaul from Lake Trashmore to the new Whitehurst Pit on Oceana Blvd. This operation requires some advance planning to develop cells in Lake Trashmore that can be sealed off and dewatered, similar to Craney Island.
Take all dredge spoils to Crany Island. The Corps of Engineers owned Craney Island is authorized to receive all navigation related dredge spoils. This option has zero impact on the Shore Drive community and no impact to the Crab Creek boat ramp. It may be more expensive to take dredge spoils to Craney due to the hauling distance, but when compared to the overall impacts to the Shore Drive area and the increased costs of road maintenance and traffic impacts, the costs are reasonable.
Dredge material from the Lynnhaven is not accepted into Craney Island - the Corps of Engineers policy is to restrict Craney Island to only navigation related to the HR Harbor, and other projects within the main harbor. Lynnhaven does not qualify.