Agenda Introductions Brief intro. past hyd. dredging programs LPC - - PowerPoint PPT Presentation

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.)

Calibrated Silt Measurement Pole Data Collection Team 2015

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

• 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)

2018 Proposed Dredge Area Tamarack Bay

* Dredge will proceed into inlet area as far as

equipment will allow

2018 Proposed Dredge Area Birch Bay

* Dredge will proceed into inlet area as far as

equipment will allow

• 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)

Hageman site for silt disposal

Hageman site for silt disposal

Dredge Discharge Pipe Route

Hageman site for silt disposal

Berm restoration (West End)

Dredge Discharge Into Basin (East End) Clear water decanting tower

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 1000 HP Diesel Engine w/ acoustic dampening Walking Spuds for propulsion Cutting head (underwater) Lift Tower for cutter Operator’s Cab 10” dia. silt discharge pipe (off photo)

Frentress Lake Marine’s –

Ancillary Dredge Equipment

HDPE Discharge Pipe (heat welded in field) Cutter Head for Dredge

What’s Next? Water Quality Improvement!

Presented By Bob Page

PRIMARY WATERSHED PROJECT SCENARIOS Lake Maintenance & Water Mgt. Improvements

Upper Watershed Conservation Practices (BMP)

Sedimentation Basin

Lake Dredging

Watershed (farms)

Lake Mgt. Practices – “GOOD”

Conventional Dredging

Lake

Residuals 1290 Tons/Yr

2100 Cubic Yards

3010 Tons/Yr

5000 Cubic Yards

4300 Tons/Yr

7100 Cubic Yards

(Non-Recoverable)

70% 30% 100%

Lake Dredging

Watershed (Farms)

Lake Mgt. Practices – “BETTER”

Farm, Combination Sediment Basin & Dredging

Dredging Lake

Residuals 970 Tons/ Year

1600 Cu. Yds.

2255 Tons / Year

3725 Cu. Yds.

4300 Tons / Year

7100 Cu. Yds.

(Non-Recoverable)

25% 75% 100% 30% 70%

1075 Tons / Year

1775 Cu. Yds.

3225 Tons / Year

5325 Cu. Yds.

Combination Sediment Basin (Hagemann Site) Lake

Lake Mgt. Practices – “BEST”

Farms, BMP, Combination Sediment Basin & Dredging

Dredging Lake

Residuals 730 Tons/ Year

1200 Cu. Yds.

1700 Tons / Year

2800 Cu. Yds.

3225 Tons / Year

5300 Cu. Yds.

(Non-Recoverable)

25% 75% 75% 30% 70%

810 Tons / Year

1330 Cu. Yds.

2420 Tons / Year

3980 Cu. Yds.

Lake Watershed (Farms & BMP)

25%

Combination Sediment Basin (Hagemann Site)

 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.

BOTTOM LINE

Dollar Saving & Water Quality Improvements Lake Mgt. Practices - “Good” to “Better”

 3036 cu yds of silt never reach the lake and are trapped

• n 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.

Lake Mgt. Practices - “Good” to “Best”

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

• 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

LAKE SUMMERSET WATER SUPPLY

Source: LPC Data

• 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

LAKE SUMMERSET (HISTORICAL)

Mudcat Dredge

(Similar to unit in 1992 Prgm.)

Topographical Map of Lake Summerset & Surrounding Area

Legend

Primary Watershed (2200 acres) Secondary Watershed (1900 acres)

Lake Summerset Watershed

• 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

LAKE SUMMERSET WATER SUPPLY

Source: LPC Data

• Primary watershed (normal annual performance)
• Delivers over 50% of rain as runoff water
• Delivers over 95% of all spring water
• Supplies 65% of the total flow to lake
• Smaller watersheds contribute 35% mostly runoff
• Total annual flow to lake 8500 acre ft.

Total flow is 25% spring and 75% runoff water

LAKE SUMMERSET WATER SUPPLY (CONT.)

Source: LPC Data

NOAA’s 24 Hr. Rain Frequency Events

Event Frequency - Years Rainfall - Inches

TH THAN ANK K YO YOU !! U !!