Rainfall
from Hurricanes Bonnie and Charley
in August caused water levels to rise
in Maryland. Streamflow levels in
southern Maryland are above normal
and an observation well in Charles
County is at its highest August level
since 1979 according to hydrologists
at the U.S. Geological Survey (USGS).
In other areas of Maryland and Delaware,
August water levels were normal to
above normal. Total freshwater flow
to the Chesapeake Bay was more than
twice the normal amount for August.
Status
of Streams and Wells
The
map below shows the location of the
wells and streams used by the USGS
to monitor water conditions in Maryland,
Delaware, and the District of Columbia.
In July, water levels were normal
in western Maryland, normal to above
normal in the Piedmont and southern
Maryland regions. Water levels ranged
from below normal to above normal
in eastern Delaware.
Precipitation
Rainfall in August
ranged from below normal to above
normal across Maryland and Delaware.
Rainfall was 3.74 inches, or 1.03
inches below normal, at Baltimore-Washington
International (BWI) Airport, and only
2.30 inches (second consecutive month)
at Hagerstown, Maryland, according
to preliminary rainfall data from
the National Weather Service. However,
summer rainfall was above normal and
temperatures were not excessive in
August. Rainfall in Wilmington, Delaware
was 1.82 inches above normal (5.33
total inches), and has been above
normal for several months. In Somerset,
Wicomico, and Worcester Counties,
Maryland, August rainfall was nearly
3 times normal. Rainfall at Washington
D.C. was 1.65 inches above normal,
with 5.09 inches.
Chesapeake
Bay
Monthly
mean streamflow into the Chesapeake
Bay during August averaged 46.2 bgd
(billion gallons per day), which is
113 percent above normal. Flow has
been above normal for the last 2 months:
See graph at http://md.water.usgs.gov/monthly/bay.html.
The Susquehanna, Potomac, and James
Rivers are the largest rivers in the
Chesapeake Bay watershed and usually
contribute about 90 percent of the
freshwater streamflow to the Bay (see
table below). In an average year,
approximately 50 percent of the freshwater
flow comes from the Susquehanna River,
25 percent from the Potomac River,
and 15 percent from the James River.
The remaining 10 percent comes from
surrounding tributaries and smaller
streams. This August, more freshwater
entered the Bay from the Susquehanna
River (68 percent) than normal, while
the Potomac and James Rivers contributed
less water than normal. The Potomac
River contributed 10 percent, the
James River 8 percent, and 14 percent
was from other sources in August.
More information about USGS studies
to help with the protection and restoration
of the Chesapeake Bay and its watershed
can be found at http://chesapeake.usgs.gov.
Streamflow
Streamflow
in Maryland and Delaware ranged from
normal to above normal levels in August.
Rainfall in western Maryland was below
normal and although streamflow levels
rose, they were at normal levels.
Streamflows in the central Maryland
Piedmont region were normal to above
normal. Southern and eastern Maryland
received more than double the normal
rainfall and streams responded with
large increases, such as on the Pocomoke
River (see hydrograph below). Current
and historical streamflow data can
be monitored on the web at: http://waterdata.usgs.gov/.
Five-year
hydrograph of monthly mean streamflow
on the Pocomoke River shows streamflow
was below normal in July (orange)
and above normal (blue) in August.
The large increase in flow was in
response to rainfall associated
with Hurricanes Bonnie and Charley.
Normal monthly mean flow is shown
by the white band. Five-year monthly
streamflow hydrographs from the
USGS stream-gaging network can be
viewed on the USGS website at: http://md.water.usgs.gov/surfacewater/streamflow/
Daily
streamflow on the Potomac River
near Washington, D.C. averaged 3.3
bgd in August, which is 24 percent
above normal for the month of August.
More information on the Potomac
River is available at: http://md.water.usgs.gov/monthly/poto.html.
Groundwater-Unconfined
or Shallow Aquifers
Abundant
rainfall throughout the summer caused
groundwater levels to rise in many
of the wells used by the USGS to monitor
unconfined or shallow aquifer response
to climatic conditions in the bi-state
region. Groundwater levels were in
the normal to above normal range during
August, and the observation well in
Charles County reached the highest
August level since 1979. For 5-year
hydrographs of groundwater levels
for the climatic indicator wells,
visit: http://md.water.usgs.gov/groundwater/.
Groundwater-Confined
or Deep Aquifers
Water
levels in the deep confined aquifers
continue to decline because the wells
are pumped at higher rates than the
rate at which deep groundwater is
recharged. Because confined aquifers
are deep, water levels in confined
aquifers respond slowly to climatic
conditions. The network of confined
aquifer wells has been reduced because
of diminishing funds. Several wells
will no longer be measured on a monthly
basis and the web pages will be updated
when data is collected. Limited data
for confined aquifer wells can be
viewed at: http://md.water.usgs.gov/groundwater.
Real-time water-level data can be
viewed at: http://waterdata.usgs.gov/md/nwis/gw
Reservoir
Storage
Storage of the Baltimore
reservoir system dropped 2 percent,
to 96 percent of capacity in August.
The Baltimore reservoirs (Loch Raven,
Liberty, and Prettyboy) have been
nearly full since May 2003. Storage
in the Triadelphia and Duckett Reservoirs
on the Patuxent River, which serves
Montgomery and Prince Georges Counties,
dropped 7 percent to 89 percent of
capacity in August.
Water
Monitoring
The
USGS has been collecting National
streamflow data for 120 years, since
1884. Streamflow monitoring began
in Maryland on the Potomac River at
Point of Rocks, Maryland in 1895 and
continues today. Streamflow and groundwater
levels are used to assess current
water conditions and can be used to
predict the potential for flooding
and drought conditions. These USGS
data have been provided to State and
local water resource managers and
are critical for making appropriate
decisions on water regulation. For
more information on streamflow and
groundwater levels in Maryland, Delaware,
and the District of Columbia, visit
Water Watch at: http://md.water.usgs.gov/waterwatch/.
The
real-time streamflow stations used
in this analysis are operated in cooperation
with the Maryland and Delaware Geological
Surveys, the Maryland State Highway
Administration, the U.S. Army Corps
of Engineers, the Maryland Department
of Natural Resources, the Maryland
Department of the Environment, Baltimore
County, Baltimore City, and other
agencies. The long-term observation
wells used in this analysis are operated
in cooperation with the Maryland and
Delaware Geological Surveys and the
Interstate Commission on the Potomac
River Basin. The real-time wells are
operated in cooperation with the Maryland
and Delaware Geological Surveys, the
Interstate Commission on the Potomac
River Basin, and Calvert County, Maryland.
The USGS publishes data for 137 streamflow
stations, 393 observation wells, and
4 springs across Delaware, Maryland,
and the District of Columbia.
The
USGS serves the Nation by providing
reliable scientific information to
describe and understand the Earth;
minimize loss of life and property
from natural disasters; manage water,
biological, energy, and mineral resources;
and enhance and protect our quality
of life.
*
* * USGS * * *
In-depth
information about USGS programs may
be found on the USGS home page at
http://www.usgs.gov
and http://chesapeake.usgs.gov/
for Chesapeake Bay activities.
|
Archived
News Releases 2000-Present |
<
< |
2004
- 08-06-2004
Localized Flooding in Northeastern
Maryland and Delaware in
July
- 07-07-2004
Water Levels Normal to Above
Normal in June
- 06-04-2004
Streams Return to Normal
Levels in Maryland and Delaware
during May 2004
- 05-06-2004
Streams Rise to Above Normal
Levels in Maryland
- 04-07-2004
Streamflow and Groundwater
Levels Fell in March 2004
- 03-04-2004
Streamflow and Groundwater
Levels Normal to Above Normal
in February 2004
- 02-04-2004
Cold, Dry January Leads
to Drop in Water Levels
- 01-06-2004
Wettest Year Leads to Record-High
Water Levels Including Third
Highest Flow to Chesapeake
Bay in December and 2003
2003
- 12-04-2003
More Record-High Water Levels
in November 2003
- 11-04-2003
Record High Groundwater
Levels in October 2003
- 10-03-2003
Flow to Chesapeake Bay in
Water Year 2003 Second Highest
Since 1937
- 09-05-2003
Third Consecutive Month
of High Flow into the Chesapeake
Bay
- 08-06-2003
Flow into Chesapeake Bay
near Record High Levels
- 07-07-2003
Record Breaking High Water
Levels in Maryland and Delaware
- 06-06-2003
Streamflow and Groundwater
Levels High in May
- 05-07-2003
April Water Levels Normal
- 04-05-2003
Water Levels High in March
- Water Restrictions Lifted
- 03-05-2003
Exceptionally Wet February
Leads to High Water Levels
- 02-06-2003
Maryland and Delaware Streamflow
and Groundwater Levels Remain
Normal in January 2003
- 01-07-2003
2002: A Record-Setting Year
for Low Groundwater Levels
- Water Levels Recover to
Normal in December 2002
2002
- 12-01-2002
Hydrologic Drought Wanes
as Water Levels Rise
- 11-01-2002
Water Levels Rise Across
Maryland and Delaware,
But Drought Persists in
Some Areas
- 10-03-2002
Water Levels Remain at Record-Setting
Lows
-
09-05-2002
Groundwater in Parts of
Maryland Reaches Lowest
Levels Since 1962, Despite
Late August Rains
-
08-06-2002
Drought Conditions Lead
to 10 Record Low Monthly
Groundwater Levels in July
- 07-03-2002
Record Low Water Levels
Show the Effects of Long-Term
Hydrologic Drought
- 06-04-2002
Groundwater Levels Reflect
Long-Term Effects of Drought
- 05-02-2002
April Showers Not Enough
to Raise Groundwater Levels
- 04-05-2002
The Drought in Full Bloom:
Low Water Levels Result
in Water Restrictions
2001
- 12-03-2001
Record Low Water Levels
Set in November
- 11-02-2001
Dry October Leads to
Low Water Levels
- 10-05-2001
Water Levels Low in Northern
Maryland
- 09-07-2001
Water Levels Stable in August
- 08-06-2001
High and Low Water Levels
in July
- 07-06-2001
Water Levels Continued to
Improve in June
- 06-06-2001
Needed Rain Helps Avert
a Drought in May
- 05-08-2001
Water Levels Still Normal
in April, but More Rain
is Needed
- 04-05-2001
Spring Rains Help Water
Levels
- 03-06-2001
Water Levels Improve, But
Are Still Below Normal
- 02-06-2001
Streamflow Still Low in
Maryland in January
- 01-05-2001
Streamflow to Chesapeake
Bay in 2000 Reflects Dry
Autumn
2000
- 12-05-2000
Streamflow in Maryland Beginning
to Show the Effects of Lack
of Rain
- 11-07-2000
Despite Lack of Rain October
Water Conditions near Normal
- 10-06-2000
September Water Conditions
Above Normal in Maryland,
Delaware, and D.C.
- 09-08-2000
August Water Conditions
Above Normal in Maryland,
Delaware, and D.C.
- 08-07-2000
July Water Conditions Continue
Normal in Maryland, Delaware,
and D.C.
- 07-07-2000
June Water Conditions Normal
in Maryland, Delaware, and
D.C.
- 06-06-2000
Water conditions begin to
decline in Maryland, Delaware,
and D.C.
- 05-05-2000
Water Conditions Continue
to Improve in Maryland,
Delaware, and D.C.
- 04-07-2000
Water Conditions Continue
to Improve in Maryland,
Delaware, and D.C.
- 03-07-2000
Water Conditions Improving
in Maryland, Delaware, and
D.C.
- 02-08-2000
January Streamflow and Ground
Water Levels Still Low
- 01-06-2000
1999 Flow Into Chesapeake
Bay Lowest Since 1960s Drought
|