NOLA.com: Playground, golf course may be used as retention pond
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Playground, golf course may be used as retention pond
By Sheila Grissett
East Jefferson bureau
Engineers have devised an emergency drainage plan
to try and save parts of East Jefferson from
flooding during another storm this hurricane
season, in part by ponding acres of rainwater at
an Old Metairie playground and golf course to keep
flood waters out of surrounding homes and the
weakened 17th Street Canal.
Some elements of the original plan plan may be in
jeopardy and not available this season, but
project engineers say they have come up with a
backup design that would still protect most of the
2,500 acres that drain into the 17th Street Canal
-- except some of Old Metairie's priciest
residential real estate.
Those homes in the low-lying, south end of
Metairie Club Gardens can also get equal
protection , but only if Metairie Country Club
allows its golf course to be used as a ponding
site to hold rainwater from the adjacent
subdivision, say engineers with Brown Cunningham
and Gannuch, the Metairie firm that Jefferson
Parish firm hired last Christmas to come up with a
backup drainage plan that could be in place when
this storm season opens June 1.
"If we don't get the golf course, then protecting
homes on Pelham, Nassau and the south side of
Northline becomes the weak part of our plan," said
Cecil Soileau, the firm's senior hydraulic
engineer.
The plan would only be used to try and avert
street and structure flooding if the Corps of
Engineers has to close new floodgates the agency
is now building in the 17th Street Canal, which
was damaged by Hurricane Katrina and is now unable
to hold more than six to seven feet of additional
surge.
The floodgates would be shut to keep excess storm
surges out of the canal, but there is a tradeoff.
When closed, the gates reduce by as much as 90
percent the ability of Pump Station 6 to move
water out of the canal, which drains the 2,500
acres of Old Metairie and Old Jefferson known as
Hoey's Basin.
The drainage plan, which is designed to help
Jefferson Parish offset that reduced drainage out
of the basin, will probably be available for use
each storm season until the corps builds a new
pump station at the mouth of the canal, which is
expected to take from three to five years if
Congress soon finances the project.
The plan is designed to store runoff from what is
commonly referred to as a 10-year-storm event, in
which 10 inches of rain falls in a 24-hour period,
such as occurred in Hurricane Allison in 2001. By
comparison, the watershed flood of May 1995 was
caused by a 500-year-storm.
As originally designed by Brown Cunningham &
Gannuch, the plan had three three major
provisions: collect and hold rainfall in two
makeshift detention ponds until it can be safely
released to drain; reverse the flow of storm water
in some underground pipes from east to west; and
divert still more water into the Mississippi
River, away from the 17th Street Canal and Lake
Pontchartrain.
But now two of the provisions are in jeopardy, and
district Councilwoman Jennifer Sneed, along with
at-large councilmen John Young and Tom Capella,
are making a full court press to save the original
plan by asking help from both the Metairie Country
Club and the Army Corps of Engineers.
The original, preferred plan calls for creating
two detention ponds, each to hold rainwater from
18 to 24 hours, by building temporary levees
around the 80-acre Metairie Country Club golf
course and the 40-acre Pontiff Playground. New
pumps would be used to suck water out of
underground drains and pumped into the playground
and golf course until each held an average of one
foot of rainwater, or 120 acre feet.
If only the playground is available, engineers
said its levees would be built higher - up to four
feet tall in spots - in order to hold an average
of three feet of water.
The mostly earthen levees wouldn't be built over
any playing fields, and a floodgate would provide
public access on most days.
During a flood event, however, the gates would
close to seal the playground, which would then be
able to contain the same 120 acre feet of water -
which Soileau said is equivalent to removing one
foot of water from 80 residential blocks.
Still, the playground would be of no help to
low-lying, southernmost Metairie Club Gardens,
which engineers said would need storage that only
the adjacent golf course could provide.
"Hopefully, we can still work something out with
the country club, but if not, the parish will do
everything it can to help the people living on
those streets, including situating a pump to
remove water from the Northline culvert and
putting it into the 17th Street Canal," Soileau
said.
A country club executive said last week that his
membership hasn't made a decision and cannot even
vote until it has more information about the plan.
Sneed, whose district includes Old Metairie, has
asked that club officials put their specific
concerns in writing as soon as possible so that a
parish engineering team can respond and negotiate.
"The clock is ticking. We have to get moving,"
said Sneed, who is ramroding parish efforts to
quickly design and implement a backup drainage
system, one that that was never needed nor
envisioned before a 17th Street Canal floodwall
breached during Hurricane Katrina and sent the
lake flooding much of New Orleans and parts of Old
Metairie and Old Jefferson, which are in the
2,500-acre Hoey's basin.
"Every portion of this plan is a piece of the pie,
and the more elements that we have, the more water
we can keep out of more homes," she said..
A club executive said his membership needs more
information before they can even entertain a vote.
"We would love to cooperate with the parish
because we are also very concerned about the
drainage this hurricane season," Metairie Country
Club Board of Governors' President David Gallo
said last week. "Our clubhouse was destroyed
(during Katrina flooding) and a lot of our members
live in this area. But what they gave us was a
preliminary plan, and we had questions they
couldn't answer. We need more information."The
second trouble spot occurs with the plan's
pump-to-the-river provision, which would divert
drainage from the lake to the Mississippi River,
thus avoiding the 17th Street Canal.
Parish officials say they don't yet know how many
millions the entire project will cost, but that
the interim pump to the river plan will be very
costly, requiring construction of a small pump
station south of Airline Drive on Hoey's Canal and
laying 7,000 feet of pipe from there to the river.
Although most of the 7-foot-diameter pipe would
snake above ground along railroad and state
highway rights-of-way, short sections would also
have to buried beneath Airline and one set of
train tracks, engineers said.
"Everything is planned. The pump station is
designed. We've been in contact with pump
manufacturers and we've gotten surveys There just
isn't any money," said Soileau, who said he and
colleague Silas Cunningham have worked to get this
project designed and ready for bidding since the
firm was hired by the parish last Christmas.
"If the money is found immediately, it can go to
bid and be done by the height of the season,"
Soileau said. "But if we wait even another six
weeks, it will be October."
Sneed has led several council delegations
imploring the corps to pay for the emergency
drainage work, which is only needed to combat the
flooding that would only occur when the corps
scloses its floodgates surge out of the crippled
canal.
"As a homeowner in this district and an official
elected to represent the district, I feel
completely abandoned in this by every other branch
of government, especially the Corps of Engineers,"
Sneed said.
"How can they prevent us from using our own
drainage system, then refuse to help us provide an
alternative? We didn't create this problem.We
aren't responsible for the floodwall that
collapsed: The corps is. And we aren't building
the floodgate in response to that collapse: The
corps is," Sneed said. "And if they have to close
the gate and enough rain falls while it's closed,
our neighborhoods can flood again.if we don't have
a backup system in place."
A corps spokeswoman told the Jefferson Parish
Council on Wednesday that the New Orleans district
expected a final decision from headquarters in a
week to 10 days that would dictate what help, if
any, the agency can provide .
Corps lawyers who interpret how the agency is
allowed to spend the money Congress provides under
specific work authorizations said there is no
money currently available for the drainage work.
"We can hope for the best, but we have to move on
with our quick and dirty plan ," said Sneed, who
said she sees no way for pump to the river this
storm season without the corps' help. "Every day
that goes by is another day lost."
If there is no pumping to the river, the backup
plan calls for buying and installing two new pumps
near Hoey's Cut, which are gates between Airline
and Northline that are closed when the 17th Street
Canal starts backing up into Jefferson Parish. If
water in Hoey's Basin started rising to an
unacceptable level, engineers said the pumps would
be turned on and some water, at the much reduced
rate, would be drained into the 17th Street Canal.
"The pumps will regulate what we pump into the
canal," said engineer Ken Brown. "We'll never put
in more than we're supposed."
Hoey's Basin is bounded east and west by the 17th
Street Canal and the Severn Avenue-Shrewsbury Road
area, and to the north and south by the the river
and Metairie Road. And because the river levee and
Metairie Road are the highest points in the basin,
rain hits the ground and runs to the lowest point,
which engineers identified as the Airline-Metairie
Country Club golf course area., closely followed
by the Pelham, Nassau and the south side of
Northline.
Engineers said it is that striking difference in
elevation - Metairie Road is 12 feet higher than
Airline - that makes it imperative to capture and
all hold as much rainfall as possible until the
17th Street Canal floodgate is reopened and giant
Pump Station 6 is allowed to resume draining the
canal at a maximim capacity of about 9,000 cubic
feet per second - not the scant 1,000 cfs to
2,6000 cfs available when the gates are closed.
A third key provision of the new plan calls for
reversing the flow of water in the Geisenheimer
Canal, which collects water from the entire basin
and, ordinarily, moves it east from LaBarre
Road,then north into Hoey's Canal and ultimately
into the 17th St. Canal.
Instead, a conglomerate of new pumps will be used
to push that water west into the Arnoult Ditch
near Shrewsbury and the Mason Ditch near Cleary
and Earhart, then into the West Metairie Canal and
finally into the Suburban Pump Station. As part of
that movement, the big dip on Airline beneath
Causeway Boulevard will also be used to hold some
water before it enters the underground system.,
engineers said.
Controls on the pumps will ensure that the water
isn't released prematurely.
"I want everybody to understand that under no
circumstances will that water be discharged until
the levels in those canals are such that they can
accept the additional flow," Sneed said. "Under no
circumstances will any other ditch, or culvert, or
neighborhood by overburdened by the water we are
holding and or moving from the Hoey's Basin."
Sneed said the parish is taking some separate but
complementary steps to help further manage
stormwater, in the event flooding threatens. She
said flap gates will be installed on all outfall
pipes that drain water into the 17th Street Canal.
Flap gates will allow water to drain off into the
canal, but they'll stop canal water from
backflowing through the pipes to flood
neighborhoods, engineers said.
"When I tell you that we are doing everything,
everythin, everything that we can to protect you,
please believe me," Sneed said.
[Sheila Grissett may be reached at 504-883-7058 or
sgri...@timespicayune.com]