TOWN HALL MEETING Lake Summerset 2018 Dredge Program Update for Members Presented By Lake Planning Committee
Agenda • Introductions • Brief intro. past hyd. dredging programs • LPC Silt Accumulation Studies • Engineering & Permitting process • Funding for Dredge Program • (3) Areas to be dredged & Equipment • Hageman site for silt disposal • What’s Next? Water Quality Improvement • Q & A
LPC Membership • Ken Malten (Co-Chairman) * • Steve Harting ( Co-Chairman) * • Bob Page * • Steve Marshall * • Mark Metzler * • Jeff Folkerts * • Marty Beierwaltes • Bill Keener • Bill Pennock – ( General Manager LSA) * Degreed Engineers
L.S. Hydraulic Dredging Programs • ~ 1977 Contracted to Beloit Pipeline & Dredge ~12 Years between dredge programs • 1989 C&C Dredging & Const. – Lake Zurich, IL 3 Years between dredge programs • 1992 Completed by LSA w/ Leased Equip. (Mud Cat) 26 Years between dredge programs • 2018 Contracted to Frentress Lake Marine • Permitting Completed • Detention basin reconstruction contracted
LPC Siltation Studies • LPC & LSA staff have worked to monitor silt levels periodically, major projects listed below: • 2009 - 2010 Full survey • 2011 – Birch & Tamarack Bay • 2015 – West End (50%) & Tamarack Bay (50%) • 2107 – West End Full • 2018 - Birch & Tamarack Bays sched. (weather permitting) Notes: 2016 silt study cancelled due to poor ice / weather issues 2018 silt study planned for Tamarack & Birch bays
Siltation Studies (cont.) • LPC staff (Mark Metzler) have adapted software to model the lake bottom • Lake depth • Silt accumulation (over multiple studies) • Calculation of silt volume (cubic yards) • Analysis of data
Siltation Studies (cont.)
Siltation Studies (cont.) Data Collection Team 2015 Calibrated Silt Measurement Pole
Excerpt from 2017 Pole Data Lot 38 to Lot 841
Siltation Studies (cont.) Cross Section Lot 16 to Lot 223
Siltation Studies (cont.) Cross Section Lot 9 to Lot 216
Siltation Studies (cont.) Cross Section Lot 38 to 841
Analysis of Siltation Studies
Engineering & Permitting Process • Greatly expanded requirements for permitting • Engaged Fehr-Graham & Montgomery Assoc. to complete engineering, applications & consulting • LPC - detailed silt studies date back 2009 • IEPA & USACE* permits have been received • The process to date has taken over two years * USACE permit is being reissued
West End Proposed Dredge Area 2018
2018 Proposed Dredge Area Tamarack Bay • Projected dredge area: inlet* to the line between lots 2241 to 1423 • Projected Silt Removal ~15,000 cu. Yds. • Silt study to be updated in winter of 2018 (weather permitting) * Dredge will proceed into inlet area as far as equipment will allow
2018 Proposed Dredge Area Birch Bay • Projected dredge area: inlet* to the line between lots 48 to 524 • Projected Silt Removal ~6,500 cu. Yds. • Silt study to be updated in winter of 2018 (weather permitting) * Dredge will proceed into inlet area as far as equipment will allow
Hageman site for silt disposal
Hageman site for silt disposal Dredge Discharge Pipe Route
Hageman site for silt disposal Clear water decanting tower Dredge Discharge Into Basin (East End) Berm restoration (West End)
Funding for Dredge Program • No “Special Assessment” will be required to fund the 2018 dredge program • Funds have been set aside yearly thru member dues going back to the 1970’s. • We have been accumulating funds for the 2018 program since 1993. • Some reallocation of funds is required between reserve accounts.
2018 Dredging Contract Awarded Frentress Lake Marine – E. Dubuque, IA • Frentress awarded berm restoration contract for Hagemann Spoils Site (work to start shortly) • Dredge operations to commence early spring 2018, cont. thru summer until completion • A single booster pump (barge mounted) will be required for Tamarack Bay. Location ~midway along pipeline • Tent. operating schedule: (6) days / wk., (10) hrs./day • Pipe discharge line will run along bottom of lake thru TX culvert (not on peoples lawns) • 60,000 cubic yards of material is targeted for removal
Frentress Lake Marine’s – High Pressure Cutting Dredge Operational Photo from Galena Territories Walking Spuds for propulsion 1000 HP Diesel Engine w/ acoustic dampening Cutting head (underwater) Lift Tower for cutter Operator’s Cab 10” dia. silt discharge pipe (off photo)
Frentress Lake Marine’s – Ancillary Dredge Equipment Cutter Head for Dredge HDPE Discharge Pipe (heat welded in field)
What’s Next? Water Quality Improvement! Presented By Bob Page
PRIMARY WATERSHED PROJECT SCENARIOS Lake Maintenance & Water Mgt. Improvements Upper Watershed Lake Dredging Conservation Practices (BMP) Sedimentation Basin
Lake Mgt. Practices – “GOOD” Conventional Dredging 100% Watershed 70% 30% ( farms ) 1290 Tons/Yr Lake 4300 Tons/Yr 2100 Cubic Yards 7100 Cubic Yards Lake Residuals ( Non-Recoverable ) Dredging 3010 Tons/Yr 5000 Cubic Yards
Lake Mgt. Practices – “BETTER” Farm, Combination Sediment Basin & Dredging 100% 25% 75% Watershed (Farms) Combination Sediment 4300 Tons / Year Basin (Hagemann Site) 7100 Cu. Yds. 70% 30% Lake 3225 Tons / Year 5325 Cu. Yds. Lake 1075 Tons / Year Residuals 1775 Cu. Yds. 970 Tons/ Year Dredging 2255 Tons / Year 1600 Cu. Yds. 3725 Cu. Yds. ( Non-Recoverable )
Lake Mgt. Practices – “BEST” Farms, BMP, Combination Sediment Basin & Dredging 75% 25% 25% 75% Watershed (Farms & BMP) Combination Sediment 3225 Tons / Year Basin (Hagemann Site) 5300 Cu. Yds. 70% 30% Lake 2420 Tons / Year 3980 Cu. Yds. Lake 810 Tons / Year Residuals 1330 Cu. Yds. 730 Tons/ Year Dredging 1700 Tons / Year 1200 Cu. Yds. 2800 Cu. Yds. ( Non-Recoverable )
BOTTOM LINE Dollar Saving & Water Quality Improvements Lake Mgt. Practices - “Good” to “Better” 1775 cu. yds. of silt never reach the lake and are trapped on the Hagemann Property. 1775 cu. yds. are removed from the Hagemann Property by mechanical means vs. dredging. Savings are (1775 cu yds) ($15.00) – (1775 cu yds) ($3.00) = $21,300 Non recoverable silt is diminished from 2100 cu yds to 1600 cu yds, a reduction of 500 cu yds. Water quality is improved because 1775 cu yds of nutrient rich silt never reaches the lake and silt load is reduced by 900 cu yds of non recoverable silt.
Lake Mgt. Practices - “Good” to “Best” 3036 cu yds of silt never reach the lake and are trapped on the farms or in the off sight sedimentation basin. 1330 cu yds are removed from the sedimentation basin mechanical vs dredging. Savings are (1330 cu yds) ($15/cu yd) – (1330 cu yds) ($3.00/cu yd) = $15,760 Non recoverable silt load to lake is reduced from 2100 cu yds to 1200 cu yds, a saving of 900 cu yds. Water quality is improved because 3030 cu yds of nutrient rich silt never reaches the lake and non recoverable silt loading to the lake is reduced by 900 cu yds.
TH THAN ANK K YO YOU !! U !! Q & A Q & A
Bac Backup kup Sl Slid ides es Beg Begin in (fo (for r Q & Q & A) A)
Summary of USDA / NRCS Land Survey Avg. Annual Erosion and Sediment Controls for Otter Creek Total Sediment (Mud) washed into L. S. 4300 Tons/Yr (4.4 Acre Ft or 1183 - 6yd dump trucks) Includes 1000 lbs of Fertilizer / Yr
Major Storm Event – June 17, 1996 8” – 10” Rainfall in 24 Hours
IEPA Dredge Permit – 2015-EA-59941
Army Corps of Eng. Dredge Permit – CEMVR – OD-P-2015-630
Frentress Lake Marine - Dredge Contract
Frentress Lake Marine – Berm Restoration Contract
Lake Summerset Algae Blooms June 2007
Lake Silt Monitoring • On going monitoring of silt accumulation in the lake (West End, Tamarack & Birch Bays). 2015 & 2016 data collection currently underway. • Preliminary results from 2015 silt data completed • Identified ~60,000 cubic yards of silt • Data collection to be completed in winter 2016 • Final report issued in Spring 2016 Lake Planning Committee
Siltation Unchecked Lake Planning Committee
LAKE SUMMERSET WATER SUPPLY • 4100 acres (6.4 sq. miles) total watershed • 1600 acres owned or controlled by L.S.A. • 2500 acres outside our control • 2170 acres of this is our primary watershed • 330 acres of this are small secondary watersheds Source: LPC Data
LAKE SUMMERSET (HISTORICAL) Early 1960’s Boise Cascade surveyed land for lake development (285 acre). Extensive water quality test by B.C. provides baseline Lake becomes operational in late 1960’s LSA conducted to stabilize secondary watersheds, shorelines & stream banks within development LSA participates in IEPA Voluntary Lake Monitoring Program (VLMP) VLMP allows LSA to compare itself with other IL lakes (yardstick) LSA developed an E Coli Testing Program for swimmers protection
Mudcat Dredge (Similar to unit in 1992 Prgm.)
Recommend
More recommend
