Lake John Association Annual Meeting June 18, 2016 Overview Water - - PowerPoint PPT Presentation

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Apr 22, 2023 223 likes •401 views

Lake John Association Annual Meeting June 18, 2016 Overview Water Quality Metrics Water Clarity (Secchi Disk Readings) Chlorophyll A Phosphorus TSI (Trophic State Index) Water Levels Invasive Species 2016 Activity

SLIDE 1

Lake John Association Annual Meeting June 18, 2016

SLIDE 2

Overview

 Water Quality Metrics

 Water Clarity (Secchi Disk Readings)  Chlorophyll A  Phosphorus  TSI (Trophic State Index)  Water Levels

 Invasive Species

 2016 Activity  Zebra Mussels

 Hand Removal – Matt Riehm, Dockside Aquatics LLC  Water Levels and Resulting Bog Situation

SLIDE 3

Water Quality Overview

 Water samples are taken every month May to

September.

 Additional Secchi Disk readings are taken and

reported to MPCA (Minnesota Pollution Control Agency) annually. (Link on website)

 Inlet water testing is performed twice annually  Secchi Disk, Chlorophyll A, Phosphorus and TSI are

reported monthly on the RMB Website (Link website)

 Full Support for North Central Hardwood Forest

Region. Few algal blooms and high transparency exist

throughout summer to support swimming (TSI <57)

SLIDE 4

Secchi Disk

 Higher number is better. Maintain higher than 4 ft

2 4 6 8 10 12 14 16 18 20 2011 2012 2013 2014 2015 2016 feet

Secchi Disk Reading - Trending

SLIDE 5

Chlorophyll

 Lower is better. Below 15.

2 4 6 8 10 12 14 2011 2012 2013 2014 2015 2016 µg/l

Chlorophyll Trending

SLIDE 6

Phosphorus

 Another Component of lake “fertility”  Lower is better. Below 40

5 10 15 20 25 30 2011 2012 2013 2014 2015 2016 µg/l

Total Phosphorus Trending

SLIDE 7

Trophic State Index (TSI)

 Calculated from sechhi disk, chlorophyll and

phosphorus

 Lower is better. Below 57

35 37 39 41 43 45 47 49 51 53 55 2008 2009 2010 2011 2012 2013 2014 2015

TSI Trending

SLIDE 8

2016 CLP Treatment Area

SLIDE 9

2016 EWM Treatment Area

SLIDE 10

Zebra Mussels

 Confirmed in at least 3 locations fall 2015  No current effective treatment strategies available  Effects on individual lakes vary and are not well

understood

 Feed on plankton at bottom of food chain  Fish population may be affected over time  Water clarity generally increases  Shells are sharp and may cut unprotected feet/hands  May plug irrigation systems and water intakes on boat motors

left in water

 Public access being monitored most days and times  Lake Sylvia pursuing $500,000 treatment plant by culverts

n Cty Rd 3 for treating inlet water for ZM

SLIDE 11

AIS Activity Update and Plan

 2015

 CLP

 27.6 Acres of CLP, $7513

 EWM

 NO treatment due to good survey results summer 2014

 Zebra Mussels found Fall 2015

 2016

 CLP

 Treated 19.3 Acres, 4/24/16, $5,412, (Survey $390)

 EWM

 Treated 12.3 Acres, 6/13/16, $5,961  Permit to treat 1 acre by rocky point  Request to treat down middle of finger denied by DNR

SLIDE 12

SLIDE 13

Water Levels

 Water levels continue to increase  Water level on 6/15 was 6.36 inches above OHM  Water level on 6/17 was 5.64 inches above OHM 

1053 1053.2 1053.4 1053.6 1053.8 1054 1054.2 Feet

Lake John Water Levels 3/2012 - 6/2015

WL OHW 1053.5 Linear (WL)

SLIDE 14

High Water and Resulting Bog Concern

 Over 30 contacts with DNR and county since 4/2015  WCSWCD comments on 6/6  DNR hydrologist and IAS visited on 6/8  County inspected culverts on Cty Rd 3 again on 6/17

SLIDE 15

High Water – WCSWCD Comments

 Satellite reception not the best during survey  Culvert is tipped the right way on 68th street the flow line

came up 1050.26 at the invert and 1049.64 on the outlet.

 Elevation on lake 1054.01 ft  Elevation at culverts 1052.15 ft  1000 feet of cattail via aerial photos can account for

difference.

 Levels have steadily increased on average over the last 10

years. This likely a result of increase rainfall and

groundwater inflow and perhaps obstruction to flow.

SLIDE 16

High Water – DNR Comments

 Blockages requiring permits will not be granted until

Lake Sylvia ZM treatment facility is operational

 GPS coordinate on the lake indicated bogs at 1,900 feet

away from the culverts at CR 3

 Flow at CR 3 appeared to be slow. I could not see the

culverts from either side – the area is inundated with water.

SLIDE 17

High Water – County Engineer

 Most water ever saw flowing thru the culverts  Questions the 2 feet difference from WCSWCD

assessment

 Water is swirling by both culverts indicating flow  Culverts were “jetted” about 6-7 years ago and nothing

was in them except a little silt

 Culverts are half full of water  Cattails definitely slow the flow down  Other lakes having problems - Sugar Lake is 8 -9