Internet Beat
Flood 2002: Canyon Lake and Guadalupe River flows
By Gloria R. Rivera
You will be able to follow and understand the flow
fluctuations pertaining to the current flooding in Seguin if you check out
these links:
The Guadalupe River inflow into Canyon Lake,
measured at the Spring Branch USGS station:
http://tx.waterdata.usgs.gov/nwis/uv/?site_no=08167500&PARAmeter_cd=00065,00060
. As of July 6 at 11:45 am, the flow is 36,900 cfs, down from 107,000 cfs
on July 3 at 12:15 pm. Use this link to see the graph that shows the changes in
flow since June 29.
The flow at the USGS gauge station at Sattler,
immediately downstream of Canyon Lake:
http://tx.waterdata.usgs.gov/nwis/uv/?site_no=08167800&PARAmeter_cd=00065,00060
. As of July 6 at 10 am, the
gage height in feet is 35 ft+, going up. Use this link to see the graph that
shows the changes in gage height since June 29.
The cfs flow from Canyon Lake is available
at http://www.swf-wc.usace.army.mil/reports/fish.htm
This is information provided by
the U. S. Army Core of Engineers in Fort Worth. The information on Canyon
Reservoir is at the very bottom of the page, and you will need to scroll down
to find it. The problem with this link is that probably so many people
are accessing it, that it seems that site is crashing over and over.
However if you are patient and try at different times without giving up, you
will be able to access the information. On Friday July 5 at midmorning, it read
60,650 cfs. This is the flow that takes nine hours to get to Seguin.
The water level at Canyon Lake is
available by USGS at http://tx.waterdata.usgs.gov/nwis/uv/?site_no=08167700&PARAmeter_cd=72020,00054
. On July 6 at 12:45 pm the
reading is 950.15 ft elevation. The spill level is 943 ft. You can
figure that there are over 7 feet of water whose release no one can control
because it is a spill. It will be possible to control the flow only after the
level in the lake goes down to 943 ft. The inflow of 36,000 cfs is not helping
at all (See Spring Branch reading).
Downstream of Sattler, there are three USGS
readings available that are directly related to the flow in Seguin: New
Braunfels above the Comal River, Comal River, and New Braunfels after the Comal
River. This is the reading that provides the information of the Guadalupe
River flow towards Seguin.
These are the url’s:
New Braunfels above the Comal River in New Braunfels: http://tx.waterdata.usgs.gov/nwis/uv/?site_no=08168500&PARAmeter_cd=00065,00060
At 12:30 pm on July 6 the reading is 68,400 cfs, surpassing the
peak on July 5. The graph showing the changes since June 29 is available at
this url. The extended changes since June 8 are available at http://tx.waterdata.usgs.gov/nwis/dv/?site_no=08168500&PARAmeter_cd=00060,00065
Comal River
http://tx.waterdata.usgs.gov/nwis/uv/?site_no=08169000&PARAmeter_cd=00065,00060
This is the flow from the Comal
Springs of the Edwards Aquifer. On July 6 at 13:00 pm the reading is
13,000 cfs. This is water that Seguin receives, in addition to the water
from Canyon.
New Braunfels, below Comal River (with
the water from Comal River): http://tx.waterdata.usgs.gov/nwis/uv/?site_no=08169500&PARAmeter_cd=00065,00060
At 12:15 pm on July 6 there is no reading for the flow, but there is
a reading for the gage height: 22.91 ft. The graph showing the changes
since June 29 is available at this url.
At this last url you can see the variations in
readings since June 29. This last link gives you the idea of what to
expect in Seguin after about three hours. The previous links, give you an
understanding of why and how.
The Guadalupe River is a system, the fluctuations in a part of a system have an
effect on a different part of the system. Unfortunately, Seguin is
experiencing the devastating repercussions of torrential rains that fell many
miles away, starting several days ago.
You can follow all the real time flows for all
rivers in Texas, including the Guadalupe River, at http://tx.waterdata.usgs.gov/nwis/current?type=flow
.
To contribute to the Internet Beat column contact
Gloria Rivera at webmaster@seguin.net