FAQ - Ohio Water Science Center
How do I get a
record of gage heights and other unit data older than 31 days?
Currently,
the only way to gage-height and unit water-quality data is by special
request. Use this link to send a
message to our information team, and be sure to specify exactly what kind of
data and what period of time you’re interested in.
Instantaneous unit streamflow data can be obtained from the
Instantaneous Data Archive, or IDA.
This repository contains only unit streamflow data and only data that have
been approved as final.
What do the
flags and remarks mean in your tab-separated unit-data retrievals?
Click
here
to get an explanatory list of these symbols.
Can I obtain a
stage-discharge rating for a particular streamgage site?
You can
obtain a shift-adjusted rating table by if streamflow (discharge) is
currently being computed at the site by entering a URL of the following
form in your browser’s address bar:
http://waterdata.usgs.gov/nwisweb/data/exsa_rat/XXXXXXXX.rdb
where XXXXXXX should be replaced by the site number.
If the streamgage is a stage-only site, no valid or current
rating exists.
How do I find the
location of a USGS streamgage in Ohio?
Go to the
Real-Time Water Data area of NWISWeb
and use the map or the Statewide Streamflow Table to bring up the site
record. If the narrative description on the real-time page is insufficient
for your purposes, you can see a mapped view by selecting “Site Map” from
the pick list under “Available data for this site.”
Why has
streamflow been discontinued at some streamgages but gage heights
(stages) are still reported?
Computation
of streamflow is an expensive part of operating a streamgage because of the
amount of fieldwork, record editing, and record review involved. If funding
for a particular streamflow site cannot be maintained at a sufficient level,
we sometimes need to downgrade a station to stage only. For some stations,
gage height is the issue of interest, not streamflow, so those streamgages
may be established as stage only from the outset.
How do I find
flood stage for a particular place on an Ohio stream?
Flood levels
are designated by the National Weather Service for their forecast sites and
consequently are not defined for all of the stream gages that the USGS
operates. If you are interested in flood and high-flow information,
try this
link.
You can quickly determine where streamflows in Ohio are high and water
levels are above flood stage. If you use the mouse to move the pointer over
one of the gage symbols, a small box is displayed which includes useful
information including the station name and number, current gage height
(stage), and flood stage (where defined). Flood stages are shown even when
current stages and streamflows are low. Detailed information on floods and
flood forecasts also can be obtained from the
National
Weather Service’s Advanced Hydrologic Prediction Service in Cleveland
and Ohio River Forecast Center in Wilmington.
What are gage
datums, and why do they have different references among the Ohio stations?
Gage datum is
a horizontal surface used as a zero point for measurement of stage or gage
height. This surface usually is located slightly below the lowest point of
the stream bottom such that the gage height is usually slightly greater than
the maximum depth of water. Because the gage datum is not an actual physical
object, the datum is usually defined by specifying the elevations of
permanent reference marks such as bridge abutments and survey monuments, and
the gage is set to agree with the reference marks. Gage datum is a local
datum that is maintained independently of any national geodetic datum.
However, if the elevation of the gage datum relative to the national datum
(North American Vertical Datum of 1988 or National Geodetic Vertical Datum
of 1912 or 1929) has been determined, then the gage readings can be
converted to elevations above the national datum by adding the elevation of
the gage datum to the gage reading.
How do I find .
. .
-the
magnitude and frequency of a particular flood?
-low-flow
and other types of flow statistics?
-drainage
area for a particular place on a stream?
You can
find answers to all these questions by use of the
StreamStats
application for Ohio. Published USGS reports are also available:
flood magnitude and
frequency (and description of StreamStats),
various
streamflow statistics,
low-flow and flow-duration statistics. Drainage-area information can
also be found in the Ohio Department of Natural Resources, Division of
Water’s
Gazetteer of Ohio streams.
How do I find
the highest measured water level (gage height, or stage) at a particular
Ohio streamgage site?
Go to the
NWISWeb surface-water area
for Ohio and select “Peak-flow Data” from the menu options. The “Table”
output format will list gage heights as well as measured annual peak flows.
How do I get
flood maps or 100-year flood heights for my neighborhood?
The
FEMA Map Service Center is the principal
source of these kinds of maps. You can even generate a customized map of
your area (a Firmette) online. Additional information, including names of
local flood administrators, can be obtained by the
Ohio Department of Natural Resources, Division of Water, Floodplain
Management Program.
How often do
your real-time stations update? Some seem to take
several hours even though the data are reported for much shorter intervals.
Data are
transmitted from gage locations every 1 to 4 hours during normal operation,
depending on the type of equipment at the station and the availability of
communications-satellite channels for relay. As technology advances, we hope
to reduce these delays. If a station hasn’t reported for a day or more,
chances are that something is wrong somewhere in the chain of data
transmission. Feel free to inform us of any apparent outages by
emailing us.
How do I get gage-height and flow information specifically for
the Ohio River?
Gage-height
data more than 31 days old (no longer showing on NWISWeb) can be requested
from the USGS Kentucky
Water Science Center or the
West Virginia Water Science
Center for Ohio River streamgages bordering their respective states;
click on “Questions about sites/data” at the bottom of the NWISWeb pages to
make an email request. The U.S.Army Corps of Engineers (USACE) also collects
information at some other locations that don't appear on our web page (for
example, see here).
Because the Ohio River is such a highly regulated stream, flow information
is very sparse; however, the USACE is generally the best source.
How/where can I
get USGS publications, including those that the Ohio Water Science
Center has produced?
The vast
majority of USGS publications, including the Ohio WSC’s, are available from
the USGS Publications Warehouse. Printed
copies of many Ohio WSC publications are available at no cost and can be
requested by email.
How/where can I
get hardcopy and digital topographic maps?
For Ohio,
hardcopy maps can be ordered from the
Ohio Department of Natural Resources, Division of Geological Survey.
They can also be ordered directly from the
USGS; digital versions are available for free download from the same Web
address.
How/where can I
get hydrologic GIS datasets?
For Ohio,
detailed watershed boundaries can be obtained from the
Ohio
Natural Resources Conservation Service (NRCS) web site. For watershed
boundaries bordering Ohio, there are a couple of good sources of data: The
NRCS Watershed Boundary Dataset site has links to
other sites and individual states are also good sources of data:
Michigan,
Indiana, and Pennsylvania.
Alternatively
you can create your own watersheds using the
USGS
StreamStats Tool.
Hydrologic
networks (GIS jargon for rivers, streams, and creeks) can be obtained in
multiple levels of detail (down to 1:24,000 scale) from the
USGS National Hydrography Dataset (NHD).
How/where can I
get aerial/satellite photos of Ohio and other places?
USGS aerial
images can be located by way of the USGS
Store. The Ohio Department of Transportation also has an
extensive set of aerial
images for Ohio. Several non-governmental sources now make aerial
imagery available to view or order online, among which are Google Maps,
Google Earth, and Terraserver.
Where can I get
current data for lakes and reservoirs and find out about reservoir
releases?
The U.S. Army
Corps of Engineers operates most of the reservoirs in Ohio and is usually
the place to go for this kind of information. The Corps’
Huntington District operates
reservoirs in eastern and central Ohio, and the
Louisville District operates a
few reservoirs in southwest Ohio. For fishing and boating purposes, the
organization “Go Fish Ohio” has
downloadable maps for
selected lakes. The USGS does have
real-time gage-height information for a few lakes and reservoirs in
Ohio.
Can I request to have a temperature
reported for a streamgage site where temperature isn’t
measured now?
Adding and
maintaining temperature equipment to a stage-only or streamflow station
costs extra money, so we need outside support to fund this addition above
and beyond the funding for stage or flow. If you would like to see
temperature readings at a favorite fishing or boating site on an Ohio
stream, contact us. We’ll explain how
you might be able to work with a tax-supported entity to help fund the
upgrade.
What’s a good and safe streamflow for
fishing at a particular site?
A given
streamflow (for example, 215 cubic feet per second (cfs)) means different
things at different sites. On a river that drains a large area, 215 cfs may
be a trickle. On a small stream, it may be a flood. If you are trying to
figure out when the river is wadeable, you might look at our
measurement
page for the gaged site of interest. You will see the gage heights
corresponding to wading measurements we have made (as indicated in the
“meas. type column”). Obviously, at a given gage height, it may be possible
to safely wade in some locations and not in others so be careful, wear a
personal flotation device, and take other precautions.
As for what’s a good flow for when the fish bite, we’re too busy tending to
our gages to have time to find out! However, there are many other places to
check. Following are just a few we know of (Note: mention of web sites does
not constitute an endorsement by me or the USGS):
Ohio Dept. of Natural
Resources, Division of Fish and Wildlife
Go Fish Ohio
Ohio Central Basin Steelheaders
Great Lakes Council of the Federation of
Fly Fishers
What’s a good and safe streamflow for
kayaking or canoeing at a particular site?
The
American Whitewater organization has a database that relates USGS
real-time data to their judgment of whether the stream is "running" too low
or too high for paddling.
Where do I find
information on USGS bench marks? For instance, if I need to get an
elevation or want to report a bench mark that's been destroyed or that needs to
be moved?
Following is
the contact information:
U.S. Geological Survey
Science
Information and Library Services
1400 Independence Road, Mail Stop 231
Rolla, MO 65401
Toll Free: 888-ASK-USGS, choose option #2
Phone: (573) 308-3500
Fax: (573) 308-3615
Email:
mcmcesic@usgs.gov
How do I get
my well tested for water quality?
Many local
health districts in Ohio offer some kind of testing. A directory of these
districts can be found at the following
Ohio Department of Health Web site.
How deep is
ground water in my area?
This is a
difficult question to answer because ground-water conditions can differ
dramatically over short distances. Also, there are many places in Ohio where
shallow ground water is underlain by deeper aquifers that yield greater
amounts of water with less susceptibility to drought. The Ohio Department of
Natural Resources, Division of Water’s
online potentiometric (water-level) surface maps and
ground-water resource maps can give you a general idea of ground-water
depth and yield in your county. The Division’s
well-log search tool can show the characteristics of water wells drilled
in your township or on your road.