The State of Deep Creek Lake, 2012 Second Annual State of Deep Creek Lake, 2012 14 November 2012...

The State of Deep Creek Lake, 2012

Second AnnualState of

Deep Creek Lake, 2012

14 November 2012

John R. Griffin, SecretaryMaryland Department of Natural Resources


Introduction

Secretary John R. Griffin

MD Department of Natural Resources


to protect the lake as a man-made resource,

preserve its ecological balance, and

maintain its use as a recreational and economic asset.

Goals for Deep Creek Lake


The state of Deep Creek Lake today is that of a healthy reservoir that meets most users needs under the federal Clean Water Act…

• Good water quality

• Diverse plant and animal life

• Moderate levels of nutrients to support aquatic life

Even so… the lake has its share of issues…


Water Quality

Bruce MichaelDirector, Resource Assessment Service



Water quality monitoring goals:

• characterize existing water quality conditions in the lake and its tributary coves – physical and chemical characteristics, levels of nutrients and primary productivity

• establish baseline conditions to evaluate trends in water quality conditions

• monitor water quality conditions at tributary stream gage sites to eventually determine nutrients and sediment loads entering the lake from the watershed


Deep Ck DamDPR0021

DPR0041

US 219Bridge

DPR0056Glendale Rd

BridgeDPR0082

DPR0069

DPR0094

Turkey NeckDPR0103

Marsh RunCove

Cherry CkCove

CCR0001Meadow Mtn

Run Cove

North GladeCove

Hoop PoleCove

Poland RunCove

Green GladeCove

Pawn RunCove

Deep CkCove

PLD0001

Lake mainstem stationLake embayment stationLake tributary station (USGS gage


• The current monitoring program has defined seasonal and spatial variations and established a baseline of conditions to evaluate how changes in population/land use in the watershed affect Deep Creek Lake.

• Deep Creek Lake has a diverse aquatic plant community with a wide range of species ranging from microscopic phytoplankton species to vascular aquatic plants, including invasive species.

• Weather conditions (temperatures/precipitation) have varied each year during the summer, which can affect some measures…

2009 - cool, moderately dry summer 2010 – very warm, dry summer 2011 - very warm, wet summer 2012 - hot, moderately dry summer

Monitoring Summary


2012 Monitoring Results

• Water temperatures in summer 2012 were highestrecorded during this monitoring period (2009-2012).

• Oxygen levels in the upper waters of the lake, pH, conductivity, and nutrients (nitrogen and phosphorus) are at levels that support a diverse biological community (plankton, aquatic plants, fish and wildlife).

• Algal levels are limited by the low concentrations of phosphorus in the lake.

• Open waters are very clear and support swimming, boating and growth of aquatic plants in deeper waters


• Health advisory to limit consumption of bass and walleye caught in the lake due to elevated mercury. This is a Statewide concern in many lakes.

• Summer oxygen levels in the cool, deep portions of the lake (greater than 21-34 feet) are too low(< 2 ppm; hypoxic) to support aquatic life. This is naturally occurring but increases in nutrients to the lake = increases in algae = longer hypoxic periods and occurrences in more shallow areas of the lake.

Water Quality Issues


Water Quality Trends, 1970-2012Long-term trends in lake productivity (measured as the amount of

chlorophyll in microscopic phytoplankton) show little change and indicates that phosphorus levels have not appreciably increased.

Long-term Assessment of Deep Creek Lake Trophic Status(Carlson TSI - summer average chlorophyll)

10

30

50

70

90

1969 1973 1977 1981 1985 1989 1993 1997 2001 2005 2009

Year

Tro

ph

ic S

tate

Ind

ica

tor

(TS

I)

.

Hypereutrophic

Eutrophic

Mesotrophic

Oligotrophic

nutrient polluted

nutrient enriched

moderate nutrients supports diverse aquatic life

nutrient poor


Water Quality Trends, 1970-2012Long term trends in electrical conductivity in the lake (a measure of input of

dissolved salts in fertilizers, septage, and deicer chemicals from the watershed) have doubled but are not yet at levels that impact aquatic life.

Deep Creek Lake mainstem stationsSpecific Conductivity (uS/cm), 1970 - 2011

0

30

60

90

120

150

70 73 76 79 82 85 88 91 94 97 00 03 06 09 12

Year

Co

nd

uct

ivit

y

-


Aquatic Vegetation


McHenry

Meadow Mountain Run Cove/ State Park

Red Run Cove

Honi Honi

Deep Creek Cove

Green Glade Cove

McHenry

Meadow Mountain Run Cove/ State Park

Red Run Cove

Honi Honi

Deep Creek Cove

Green Glade Cove

Locations of DNR’s Aquatic Vegetation survey transects,2010-2012


2012 EWM shoreline survey summary – I

86 acres of Eurasian water milfoil (EWM) were mapped in a complete shoreline survey conducted July 9-10, 2012– 2.3% of the lake surface

– 5.8% of shallow (less than 6m deep) water

– EWM co-occurred with other SAV species

Northwest half of Deep Creek Lake


2012 EWM shoreline survey summary - II

Transect data indicate no significant difference in percent cover of EWM between 2010, 2011 and/or 2012

Seen from the surface, other native submerged grasses are far more common, specifically Potamogetons and Vallisneria, which occupy virtually all of the lake shallows

Southeast half of Deep Creek Lake


Control options for EWMMost effective / lowest impact large scale (acres) control option

is the use of herbicide 2,4-D (repeated application necessary over years)

• Cost of $500 to $1000/acre• Can be used in “spot” treatments• Low toxicity to most fish (some salts are highly toxic to trout), but might be an

endocrine disruptor to aquatic vertebrates

Localized control measures include benthic barriers or hand removal

• Care must be used to capture all hand-harvested removal to minimize spread• Benthic barriers are expensive per unit area (4 installations in 2012; $300-

500/mat – cost, install, removal), but very effective• Hand removal is inexpensive and very low impact, but is inefficient

Mechanical harvesting• Expensive ($8-10,000 for two days)• Risk of spreading EWM from fragments or introducing other SAV species

carried in on equipment from other water bodies


EWM Control options rejected / reasonsHerbicides other than 2,4-D• Some impacts to other SAV species and/or fish

• Less effective in DCL – due to the large lake volume ($300-500/acre)

Biological controls• Grass carp are illegal in Maryland

• Milfoil weevils haven’t been approved for importation into the state by Invasive Species Matrix Team

– Risk of escape into Chesapeake / other waterbodies

• Very expensive ($1,000s per acre)

– Efficacy uncertain in Deep Creek Lake

– In other regions, EWM control is very slow

– Controls are vulnerable to sunfish predation - DCL has a lot of sunfish


Going forward…

• Continue transect surveys at 6 locations in the lake (3 times per year)

• Monitor / assess Eurasian water milfoil– Complete statistical analyses– Conduct 2nd targeted EWM survey in June 2013

• Implement pilot control actions– Monitor results to guide future actions


Pilot project proposed to evaluate effectiveness of EWM control measures in selected Deep Creek Lake sites

– Herbicide (2,4-D) control – location TBD

– Harvest of limited areas – location TBD


Sedimentation

Phase II – DCL Sediment Plan


Lake Sediments - Completed Field Work• April 2012 - Field Work

– Sub-bottom seismic survey and bathymetry collected along transects throughout the lake.

– Complete sidescan sonar imagery of the lake and GPS-referenced shoreline video inventory

• May-September 2012 - Data processing / analysis– QA/QC and processing/correcting and interpretation of data results– Identify areas of sedimentation / no sedimentation using sidescan imagery,

bathymetric comparisons, and sub-bottom seismic data.

• October 2012 – Field Work– Collected 42 sediment cores throughout lake and analyzed selected cores

and deposited sediment for chemicals and pollutants. All samples were determined and documented to have no pollutants at detectable and reportable levels.

– Alternatives Analysis and Sediment Reduction contracts have been written and are awaiting the bidding process.


Sub-Bottom Seismic/Bathymetry Survey Coverage


Sediment Cores

– 42 Cores collected throughout lake

– Core lengths ranged from 0 (Rock confirmation) to 7 feet in length. The average collected length of each core was 3 feet.

– Cores were described, photographed, and sampled. Select samples are being analyzed for pollutants, chemical properties, and physical properties.


Future Plan

• November 2012 – May 2013– Complete analysis of sedimentation within the Lake

and publish a comprehensive report (February 2013)

– Contractors will develop a sediment reduction plan to be provided to state and local governments and landowners. (May 2013)

– Contractors will develop an alternatives analysis determining if dredging is recommended. If so, they will identify costs, methods, and impacts.


Fisheries


Status of the FisheryRemember that:

in summer 2010, about 10,000 fish died in the lake from a bacterial infection. Yellow perch, Walleye, and Smallmouth bass were most affected.


Spring 2012 Walleye Survey

Walleye are the most abundant game fish species in the Deep Creek Lake with diverse size classes including trophy-sized fish over 20 inches long. The 2012 adult walleye abundance value was one of the highest recorded to date in Deep Creek Lake.


Also in Spring 2012…Maryland DNR Fisheries Service conducted a corrective stocking of 10,000 fingerling Largemouth Bass. These were stocked at several locations in Deep Creek Lake in response to losses from the 2010 fish kill event.


Summer 2012 – Conducted seining surveys to monitor reproductive success for Largemouth Bass, Smallmouth Bass, and Yellow Perch. Reproductive success in 2012 was rated as: - “Good” for Largemouth Bass; - “Excellent” for Smallmouth Bass; and - “Excellent” for Yellow Perch


Summer – Fall 2012:MD DNR Fisheries Service obtained length, weight, and angler catch data during bass tournaments held on Deep Creek Lake. Analysis of these data have not been completed, but size of fish and catch rates among anglers appear to have improved since the 2010 fish kill event.


Fall 2012 – Comprehensive Fish Population Survey - scheduled for Oct. 31, but delayed by some snow on the ground…


Lake Water Levels

John GraceWater Management Administration

MD Department of the Environment


Uses of the Lake

Deputy Secretary Joe Gill



BoatingBoating


• 5,300 boats, including 600 PWCs• Trend - bigger boats, e.g., 26-foot boat with

molded platform• Trend – wider, longer piers• Wake-boarding• Recent regulatory changes

– Limits on powerboats– Limits on wakeboarding

Boating


• Carrying capacity• 2003 study – tolerance to crowding on the

surface of the Lake by various types of recreational boating activity

• No study on maximum “build-out” of dock slips on the Lake

Boating


Marinas


Marinas

• Mini-marina requirements• Impact to Deep Creek Lake

- Town Center- Town Residential- Assessment

• Illustrates need to manage shoreline in concert with the Lake

• Illustrates larger need to manage watershed


Lake / Watershed Management

Secretary John R. Griffin



“A lake is a reflection of its watershed”…

DNR manages only a small portion of the Deep Creek Lake watershed - mostly the lake and buffer areas at the end of each sub-watershed.Private holdings make up most of the watershed.As land use changes occur in the watershed, characteristics of the lake also will change. Addressing stresses in the watershed will slow changes in the quality of the lake and will maintain current conditions for this important asset for the county and State.

Image source: Chesapeake EcoCheck. 2011. Deep Creek Lake baselinecondition assessment”. 4p. Online at: http://www.eco-check.org


Our greatest collective challenge…

To take a watershed approach tofuture lake management.


Individual Testimony

The State of Deep Creek Lake, 2012 Second Annual State of Deep Creek Lake, 2012 14 November 2012...

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