Transcript The State of Deep Creek Lake, 2012 Summer

The State of Deep Creek Lake, 2012
Second Annual
State of
Deep Creek Lake,
2012
14 November 2012
John R. Griffin, Secretary
Maryland Department of Natural Resources
The State of Deep Creek Lake, 2012
Introduction
Secretary John R. Griffin
MD Department of Natural Resources
The State of Deep Creek Lake, 2012
Goals for Deep Creek Lake
 to protect the lake as a man-made resource,
 preserve its ecological balance, and
 maintain its use as a recreational and
economic asset.
The State of Deep Creek Lake, 2012
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…
The State of Deep Creek Lake, 2012
Water Quality
Bruce Michael
Director, Resource Assessment Service
MD Department of Natural Resources
The State of Deep Creek Lake, 2012
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
The State of Deep Creek Lake, 2012
CCR0001
Cherry Ck
Cove
Marsh Run
Cove
Deep Ck Dam
DPR0021
US 219
Bridge
DPR0056
Meadow Mtn
Run Cove
North Glade
Cove
Poland Run
Cove
PLD0001
DPR0069
Glendale Rd
Bridge
DPR0082
DPR0041
Lake mainstem station
Lake embayment station
Lake tributary station (USGS gage
DPR0094
Hoop Pole
Cove
Turkey Neck
DPR0103
Green Glade
Cove
Pawn Run
Cove
Deep Ck
Cove
The State of Deep Creek Lake, 2012
Monitoring Summary
• 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
The State of Deep Creek Lake, 2012
2012 Monitoring Results
• Water temperatures in summer 2012 were highest
recorded 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
The State of Deep Creek Lake, 2012
Water Quality Issues
• 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.
The State of Deep Creek Lake, 2012
Water Quality Trends, 1970-2012
Long-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)
.
90
nutrient polluted
Trophic State Indicator (TSI)
Hypereutrophic
70
nutrient enriched
Eutrophic
50
moderate nutrients supports
diverse aquatic life
Mesotrophic
30
nutrient poor
Oligotrophic
10
1969 1973 1977 1981 1985 1989 1993 1997 2001 2005 2009
Year
The State of Deep Creek Lake, 2012
Water Quality Trends, 1970-2012
Long 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 stations
Specific Conductivity (uS/cm), 1970 - 2011
Conductivity
-
150
120
90
60
30
0
70
73
76
79
82
85
88
91
Year
94
97
00
03
06
09
12
The State of Deep Creek Lake, 2012
Aquatic Vegetation
The State of Deep Creek Lake, 2012
McHenry
Locations of
DNR’s Aquatic
Vegetation
survey transects,
2010-2012
Meadow Mountain
Run Cove/State Park
Red Run
Cove
Honi
Honi
Green Glade
Cove
Deep
Creek Cove
The State of Deep Creek Lake, 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
The State of Deep Creek Lake, 2012
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
The State of Deep Creek Lake, 2012
Control options for EWM
Most 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; $300500/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
The State of Deep Creek Lake, 2012
EWM Control options rejected / reasons
Herbicides 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
The State of Deep Creek Lake, 2012
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
The State of Deep Creek Lake, 2012
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
The State of Deep Creek Lake, 2012
Sedimentation
Phase II – DCL Sediment Plan
The State of Deep Creek Lake, 2012
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.
The State of Deep Creek Lake, 2012
Sub-Bottom Seismic/Bathymetry Survey Coverage
The State of Deep Creek Lake, 2012
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.
The State of Deep Creek Lake, 2012
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.
The State of Deep Creek Lake, 2012
Fisheries
The State of Deep Creek Lake, 2012
Status of the Fishery
Remember 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.
The State of Deep Creek Lake, 2012
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.
The State of Deep Creek Lake, 2012
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.
The State of Deep Creek Lake, 2012
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
The State of Deep Creek Lake, 2012
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.
The State of Deep Creek Lake, 2012
Fall 2012 – Comprehensive Fish Population Survey
- scheduled for Oct. 31, but delayed by some snow on the ground…
The State of Deep Creek Lake, 2012
Lake Water Levels
John Grace
Water Management Administration
MD Department of the Environment
The State of Deep Creek Lake, 2012
Uses of the Lake
Deputy Secretary Joe Gill
MD Department of Natural Resources
The State of Deep Creek Lake, 2012
Boating
Boating
The State of Deep Creek Lake, 2012
Boating
• 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
The State of Deep Creek Lake, 2012
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
The State of Deep Creek Lake, 2012
Marinas
The State of Deep Creek Lake, 2012
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
The State of Deep Creek Lake, 2012
Lake / Watershed Management
Secretary John R. Griffin
MD Department of Natural Resources
The State of Deep Creek Lake, 2012
“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 baseline
condition assessment”. 4p. Online at:
http://www.eco-check.org
The State of Deep Creek Lake, 2012
Our greatest collective
challenge…
To take a watershed approach to
future lake management.
The State of Deep Creek Lake, 2012
Individual Testimony