woodglen lake dredging and restoration
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Woodglen Lake Dredging and Restoration Department of Public Works and Environmental ServicesTRANSCRIPT
Woodglen Lake Dredging and Restoration Department of Public Works and Environmental Services
Woodglen Lake Facts
Lake Surface Area = 12.5 acres
Sediment Pool Capacity = 160,000 cubic yards (CY)
Current sediment in lake = 32,500 CY
Estimated annual sediment load = 1,244 CY
17 feet
32,500 CY
Watershed
Drainage Area = 740 acres (1.15 square miles)
Pohick Creek Watershed
Sideburn Branch
Woodglen Lake
Woodglen Lake: Sediment Thickness
Woodglen Lake: Water Depth
Inactive Dewatering Basin
Woodglen Lake: Dewatering Basin
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Lake Restoration and Dredging Project
Project Goals
Restore sediment pool capacity
Downstream water quality benefits
Lake water quality
Esthetics
Improve lake water quality and habitat
Stabilize stream segment
Provide long term maintenance improvements
Dredging Alternatives
1. Mechanically dredge deposited sediment and haul wet
2. Drain lake and dry deposited sediment in place before hauling
PRE-DREDGING: An estimated 35,000 cubic yards of sediment had accumulated in the lake, forming islands and reducing water levels to less than three feet in most areas.
Lake Barton Example
Lake Barton Example: Pre-Dredging
Lake Barton Example: Dredging in Progress
DREDGING: Dredging took place without draining the lake.
Lake Barton Example: Dredging in Progress
Lake Barton Example: Completed Project
Lake Needwood Example
Lake Needwood: Montgomery County, MD
Dredging: The lake was drained and the sediment was dried in-place.
Lake Needwood Example: Dredging
Dredge Alternative – In the Wet
General Sequence Establish access and staging areas
Conduct dredging utilizing barges
Haul wet sediment to disposal site for drying
Benefits Less weather dependent
Quicker initial start to dredging
Less potential for schedule extensions or delay
Concerns Increased sediment handling effort at disposal area
Potentially higher cost
Dredge Alternative – In the Dry
General Sequence Initiate drawdown of lake Establish access and staging areas Establish diversion channels within lake Conduct dredging
Benefits Higher daily sediment removal rates Minimal sediment handling effort at disposal area Potentially lower cost
Concerns Very weather dependent Higher potential for delays due to weather Typically more odor from entire lake bottom being exposed Need to relocate/salvage fish
Dredging: 32,500 Cubic Yards
Woodglen Lake
Staging Area
Lake Restoration
In-lake forebay
Wetland planting
Shoreline stabilization
Fish habitat
Fish stocking
Lake Barton: Fish stocking by Virginia Game and Inland Fisheries
Fish habitat created from salvaged trees
Chesapeake Bay Preservation Areas
Buffer Restoration
Woodglen Lake: Shoreline Restoration
Woodglen Lake: Shoreline Restoration
Woodglen Lake Existing Conditions
Shoreline Protection Options
Fish Habitat Structures
Stream Stabilization
Woodglen Lake: Site Access & Staging
Access During Construction
Lake Barton
Huntsman Lake
2011
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©2013 Microsoft Corporation © 2012 Nokia
Woodglen Lake
Woodglen Lake Dredging and Restoration Project Timeline and Coordination
Community coordination at Design and Construction phase
June 2013: Final Design
July 2013: Construction bid advertisement
September/October 2013: Begin dredging
Project duration: 6 - 7 months
Lake may be drained for entire project (dredging method depends on project bidding) Partial lake drawdown alternative to be evaluated
Woodglen Lake Dredging and Restoration
Contacts
Dipmani Kumar, Project Manager 703-324-4612
Matt Meyers, Branch Chief 703-324-5651
Partners: