LAKE LORELEI DREDGING COMMITTEE UPDATE APRIL 21, 2018 Dredging - PDF document

4/24/2018 LAKE LORELEI DREDGING COMMITTEE UPDATE APRIL 21, 2018 Dredging Committee John Wyman Chairman Areas as and Depths Dredgin ing g Methods ds Mike Powell Fran Nimmons Scott Kaufman Chris Johnstone Cindi Wetzel Waste e Disposal l Sites Permit it Requir irem emen ents John Wyman TJ Jackson George Mason 1

4/24/2018 Committee Goal: Provi vide de written itten repor ort t to the Board of Trus ustees tees discu cussi sing ng all aspects ects of dredg dgin ing at all l 3 lakes es with th conclu lusion sions s and reco commen endation tions s on these se items: s: - Silt Depth and approximate quantities to be removed - Most efficient/economical combination of dredging methods - Transfer/Disposal sites including preparation and rehabilitation - Timing and requirements for obtaining permits - Bid and award procedures - Estimated costs - Sale/Use of dredged materials - Funding options Definitions Cubic Yard d (cy): ): Unit of measurement that refers to the amount of materials removed. Muck: Combination of Silt, Clay Organics and Debris Dredgin ing: g: Removing muck, sediment and debris from lake bottom Hard Pan: Lake Bottom Original Depth 2

4/24/2018 Why is Dredging Necessary: 1- Greatly improves Water Quality, which improves the lives of fish and fishing opportunities; 2- Boats will have more water under the boat and less sediment will get caught in the propeller; 3- Lake habitat is restored; 4- Removes toxic substances (fertilizers from farms), reduces rooted aquatic growth (algae and plants) and lessons sediment resuspension winds and waves. When is it time to dredge: First Signs: 1- Boat motors start churning up mud; 2- Unsightly weeds/algae begin to emerge. At first this area is limited to a small area. However, over time, this area grows and the surface water area starts shrinking in size. It becomes more difficult to maneuver boats without damaging expensive motors. 3

4/24/2018 When is it time to dredge: Second Sign: 1- Water Quality begins to deteriorate. After rainfall or high winds, more sediment is deposited and re-suspended. The water takes longer to clear and it is a murky brown color. The water quality is noticeably lower than in years past. This reflects on the aesthetics of the entire community. Muck Removal/Depths - Gary Brainard (Dredge Resources) has been hired by the Board to assist in determining approximate silt depth in each dredging area. - Every company has recommended dredging from the ‘Hard Pan’ up to 6 - 7’ water depths (below the light level) 4

4/24/2018 Dredging Areas Cove A Dredging Areas Cove B 5

4/24/2018 Dredging Areas East Beach Dredging Areas Cove C 6

4/24/2018 Dredging Areas Elm Cove Dredging Areas Cove D 7

4/24/2018 Dredging Areas Cove E Dredging Areas Inlet North 8

4/24/2018 Dredging Areas Inlet Middle Dredging Areas Inlet South 9

4/24/2018 Dredging Areas Cove F Dredging Areas Cove G 10

4/24/2018 Dredging Areas Cove H Dredging Areas Cove I Including Grunewald and Fichtelberg 11

4/24/2018 Dredging Methods Available 1- Hydraulic Dredging - to settling basins or bags - to dewatering equipment 2-Mechanical Dredging - Water Based from Barges - Land Based with long reach excavator - Lake Bottom Based when water is down Hydraulic Dredging “A floating dredge using a centrifugal pump to draw mud or sand and discharge it elsewhere.” 12

4/24/2018 Mechanical Dredging- Water Based “Mechanically digging or gathering sediment from the bottom surface of a body of water, typically through the use of a bucket located on a barge. The material that is dredged is loaded into a secondary barge and hauled away.” Mechanical Dredging- Land Based: “Mechanically digging or gathering sediment from the bottom surface of a body of water, typically through the use of a bucket from the shore. The material that is dredged is loaded in a truck and hauled away.” 13

4/24/2018 Mechanical Dredging - Lake Bottom Based : “Lower water level 6 -8 feet and excavate materials directly from lake bottom. ” Companies es Inter ervi viewed ed - Dredge Resources- January 23, 2018 - Mootz Construction- March 2, 2018 - Davis Aquatic and Env. Ser. - March 14, 2018 - McCullough Excavating and Silt Removal- March 16, 2018 - Dredgit- Waiting on sample results before meeting 14

4/24/2018 Dredge e Resour urces es Experience: Hidden Valley Lake and Kentucky Lake - Can do Hydraulic, Mechanical and Land Dredging Recommend Optimal Water Depth of 6-7 ’ - Need Transfer Points and Disposal Sites - Work Monday-Thursday - Site prep and rehab - Charges by the day Mootz Constructi ction Experience: Heritage Lake and Citizens Energy - Performs Mechanical, Hydraulic and Land Dredging - Charges by the month - Does not guarantee cy removal 15

4/24/2018 Davis Aquatic ic and Environmen mental tal Services ces Experience: Lake Seneca and Hidden Valley - Able to do Hydraulic and Mechanical Dredging - Recommend Optimal Water Depth of 6- 7’ Hydraulic Dredging - Bags 200’ long x 20’ Wide x 9’ High (1000cy capacity) - Need level surface and can stack - Dry out after one season and can haul away - 300 cy/day + 3000 gallons of water - Stay 5’ away from docks Davis Aquatic ic and Environmen mental tal Services ces Mechanical Dredge from Barges - Need Transfer Points and Disposal Sites - Can remove 12-18,000 cy per month - Stay 5’ away from docks 16

4/24/2018 McCulloug ough h Excavatin ting and Silt Removal al - Able to do Hydraulic and Mechanical Dredging - Recommend Optimal Water Depth of 6- 7’ - Can get 3’ away from docks - Can remove 200,000 cy in 8 months - Need on-site Disposal - Recommends Erosion Control and Silt Pond at Glady’s Run - Recommends doing Grunewald and Fichtelberg last Disposal Site Options 1- Keep On Site - Total area needed contingent upon Cubic Yards Removed - Committee investigating viable areas 2- Haul Off Site - Increases cost due to additional time and Distance to Haul - Increases cost due to site lease/disposal fees Also Being Investigated: - Possible uses of removed materials (requires cleaning and testing) 17

4/24/2018 Permits 1- Investigating State and Local Requirements. Clean Water Act. 2- Investigating what other lakes in the areas were required to obtain. Permit Requirements continues to be investigated with ODNR, Army Corp of Engineers, Brown County and State of Ohio. Plans need to be finalized before seekigng Permits/Permissions - Lake Lakengren- No Permit Required - Hidden Valley- Letter from USACE, No Permit Required - Waynoka- No Permit Required initially. OEPA now required - Heritage Lake- USACE contact Lake Communities Interviewed Lake Lakengren Lake Waynoka Hidden Valley Lake 18

4/24/2018 Lake Communities Interviewed Lake Lakengren (near Eaton, Ohio) - Mechanical from barges - Purchased own equipment - Peformed by Lakengren Maintanance Staff - Removed approx. 120,000 cy of sediment over 6 years Annual Operating Budget- $1,405,739.00 Main Lake Size- 207 Acre Constructed in 1969 Lake Communities Interviewed Hidden Valley Lake (near Lawrenceburg, IN) - Mechanical from barges - Removed approx. 55,000 cy of sediment over 10 years - Cost- $880,000 - Cleaned and used materials as fill and topsoil Annual Operating Budget- $2,299,000.00 Main Lake Size- 150 Acre Constructed in 1972 19

4/24/2018 Lake Communities Interviewed Lake Waynoka Meeting in May, 2018 - Mechanical Dredging from Barge - Work performed by Waynoka Staff Annual Operating Budget- $1,690,000.00 Main Lake Size- 290 Acre Constructed in 1970 Our Lake Lake Lorelei Annual Operating Budget- $769,718.00 Main Lake Size- 188 Acre Constructed in 1968 20

4/24/2018 Previous Lorelei Dredging 1991-1992: Hydraulic Dredging with Settling Basins at Fichtelberg Plain 1- North End Inlet (1991) - Average Sediment Depth- 19.27” - Approximate Cubic Yards Removed- 34,198 cy 2- Lake Fichtelberg (1992) - Average Sediment Depth- 22.22” - Approximate Cubic Yards Removed- 29,486 cy Cost: - $198,527.50 funded by special assessment of $232,000 What’s Next for the Committee: Complete research and finalize: - Silt depth and approximate quantities to be removed - Most efficient/economical combination of dredging methods - Transfer/Disposal sites including preparation and rehabilitation - Timing and requirements for obtaining permits Research and Finalize: - Bid and award procedures - Estimated costs - Sale/Use of dredged materials - Funding options 21