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WHAT IS THE GRAVEL BAR?
The gravel bar is an accumulation of debris and silty
sediment in what was once known as the deep end of the
pool behind the downstream dam. The debris ranges from
pebbles to softball sized stones to boulders bigger than
babies.
WHERE DID THE GRAVEL BAR COME FROM?
Barton Springs sits at the downstream end of a 115 sq mile
river drainage whose natural course carries water and debris
into the river. The dams built to create Barton Springs also
created a barrier that traps debris from every large flood
(those that top the upstream dam of the pool). The current
gravel bar is an accumulation of almost 20 years of debris.
HOW DOES THE GRAVEL BAR AFFECT THE WATER QUALITY OF THE
POOL?
The flood debris traps an extraordinary amount of sediment
in the pool which is easily disturbed by swimmers and
bathers which in turn makes the water more murky more
often.
DOES THE GRAVEL BAR AFFECT THE FLOW OF WATER IN THE POOL?
Flow in Barton Springs is determined by the output of the
springs. However, the gravel bar impedes the natural flow of
the pool as it has completely filled in the original creekbed
channel. If left unattended, the accumulating debris would
eventually convert our swimming pool into a wading pool.
IS THE GRAVEL BAR RELATED TO THE BYPASS TUNNEL?
No. The bypass tunnel is separated from the gravel bar to be
removed by approximately thirty feet. The city is considering
working on the bypass and the gravel bar simultaneously to
minimize the time the pool will be closed.
WHY SHOULD WE REMOVE THE GRAVEL BAR NOW?
Removing the gravel bar will have immediate benefits to your
Barton Springs experience, (such as improved water clarity
and a return of the deep end) and open the path to further
studies to improve the quality of our pool. Historically, the
gravel bars have been effectively removed approximately
every ten years using front-end loaders, trucks, and/or
cranes. We are now approaching 20 years since the last
thorough removal, and the degrading effects of this neglect
are all too obvious as each day goes by.
WHAT IS THE ECOLOGICAL IMPACT OF REMOVING THE GRAVEL BAR?
The city and citizens’ input have shown a very high level of
respect for the aquatic and terrestrial environments in the
extensive planning to prevent, mitigate, and repair any
ecological impact.
A coffer dam will isolate the area inside the pool itself; any
equipment operating in the pool will be using
environmentally friendly fuels and oils; and the staff
biologists plans to replant native species in the submerged
area once the debris has been removed. Above ground, all
heavy equipment will be kept a safe distance from the pool
and a temporary transport path made from a thick layer of
mulch and timbers will be used to avoid any soil compaction
and damaging of tree roots.
WILL THIS FIX THE GRAVEL BAR PROBLEM?
Currently, this is a periodic maintenance issue as gravel
accumulates every time Barton Creek has a large flood.
However, removing the gravel bar will allow for complete and
thorough study of the pool to find ways we can best address
the issues affecting our pool for the generations of the 21st
century.
DOES MY OPINION MATTER?
Of course! Concerned citizens like yourself have moved the
city to address this issue. The city needs direction, impetus,
and guidance from its citizens and the gravel bar removal is
a public process open to all. Please participate.
For more information please visit:
http://www.ci.austin.tx.us/parks/bartonspringsmp.htm, or
http://friendsofbartonspringspool.org/
Please consider coming to give comments Thursday evening at the Gravel Bar Public Hearing:
Thursday, January 14, 2010
301 W. Second Street, Austin, TX
For meeting information, contact City Clerk, 974-2210