Fw: [CAD] Cities scramble to shield water
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Cities scramble to shield water
By Stacey Singer
Palm Beach Post Staff Writer
Sunday, May 13, 2007
The most critical map in the water district's war room shows a solid
orange line stretching from Tequesta to Hallandale Beach, the leading
edge of an underground enemy that threatens coastal communities'
As water managers combat the drought, their top priority is defending
well fields east of that line from subterranean saltwater intrusion.
Ocean water is three times saltier than human blood, and it tastes
unpleasant. Drinking too much can lead to death. It corrodes pipes
and damages equipment. Once a well goes salty, it's useless.
Well fields in Riviera Beach, Manalapan, Boynton Beach, Delray Beach,
Highland Beach and Boca Raton all sit inside or near the map's orange
saltwater-intrusion line. A wedge runs from the ocean into the porous
coastal rock, where it lurks beneath a layer of fresh water that
supplies the wells. A prolonged lack of rainfall increases the risk
that pumps will suck brine rather than fresh water.
Of all Palm Beach County's coastal communities, Lake Worth and
Lantana face the biggest risk with well fields, water managers
Mark Elsner has their names circled in red on his map. Elsner, in
charge of implementing the South Florida Water Management District's
water supply policy, says those communities lack back-up sources. To
the south, Broward County's Hillsboro Beach, Dania Beach and
Hallandale Beach face the same risk.
To save these coastal well fields, the entire region conserves.
Lacking rain, golf courses turn patchy. Hibiscus hedges wilt.
Nurseries' business evaporates. Cars grow dingy. And homeowners
contemplate the cost of re-sodding.
Every conservation effort helps, says Chip Merriam, deputy executive
director for the water district. At the district's headquarters, the
thermostat has been turned up to 80 degrees. Less energy required for
air conditioning means Florida Power & Light needs less water.
Merriam's shirt sleeves are rolled up, his hair a bit damp from the
heat. Explaining his strategy to hold the orange line, he looks and
sounds like a battalion commander low on ammo.
With almost no water available from Lake Okeechobee, his infantry has
shut off water to most of the region's tributary canals. Instead,
water is shunted to coastal canals. The fresh water acts like a
weight, providing pressure that, in theory, will keep the heavier
salt water pushed below the lighter fresh water that feeds the public
"Normally we let canals carry water from the conservation area to
recharge the well heads," Merriam said. "Now we're trying to protect
those well heads."
It's not an ideal strategy. It pulls down the water table in the
center part of the county, making the need to conserve regionwide
But it buys time for the wells most at risk.
June typically brings Florida's rainy season. The long-range weather
forecast maps on Merriam's paper-strewn desk suggest it won't arrive
on time. So Merriam plans for the worst.
Lantana highlights intrusion problem
Salt readings in the production wells have not changed, but nearby
monitoring wells, which run deeper, have Merriam worried. He
recommended that some coastal wells be turned off for at least 60
days, while wells farther west carried their load.
In Lantana's case, the back-up wells are just a few blocks from those
Jerry Darr is the soft-spoken director of Lantana's utility. A whiff
of incense and a soothing screen saver in his office are the only
signs that he's under stress. He has worked for the town for nearly
20 years. He knows his wells.
"We're migrating our wells as far west as we can," he says. "We've
shut down wells 3, 4, 5 and 6."
But in a town that's just 2 square miles, the remaining wells are
close to the coast, too.
The district is watching Lantana closely, as the monitoring wells -
used only as a way to predict risk to the production wells - detect
rising chloride. One has a reading 17 times the allowable limit for
Lantana officials think the information is bad. They are digging new
monitoring wells but hedging bets by digging new drinking water
wells, too, near Interstate 95.
Historically, the orange line of underground salt water has pushed
past Lantana's new I-95 well, Elsner said. Lantana's other backup
plan, to open valves that link to Lake Worth's supply, doesn't offer
"If you're a city with limited options and you're interconnecting
with another city with limited options, it's not the best situation,"
In late 2008 or early 2009, Lake Worth will be in a better position,
assuming that concerns about nutrient-laden discharge near a coral
reef don't cause new delays. Lake Worth, like Jupiter, Manalapan and
Highland Beach, is building a reverse-osmosis plant that will strip
the chloride from the salty deep aquifer.
Reverse osmosis-treated water tastes a bit different, lacking
minerals. Customers' bills have risen, too, but their supply isn't at
Other communities - Riviera Beach, Boynton Beach, Delray Beach and
Boca Raton - have dug wells west of Military Trail, or tapped other
systems, so the loss of eastern wells won't create a crisis. They
wanted Lantana to do the same, but when town staffers explored the
possibility a few years ago, they found the $15 million cost more
than the town could afford.
Using Everglades water considered
So for now, the priority is to weigh down coastal canals with water.
The water district has asked the U.S. Army Corps of Engineers to bend
its rules on taking water from the Everglades if the situation grows
The proposal is getting a great deal of research and discussion,
engineers at the Jacksonville office say. The corps has asked the
district to draft a clear set of standards that would trigger
overriding Everglades protection rules.
It will use sentinel monitoring wells, watching their depth and their
levels of salt. Also under study is how much of a release would do
The agencies have conference calls every other day to hear where
things stand with the lake, the drinking water supply, the saltwater
incursion issue, and the health of the too-dry wetlands.
Most birds' hatchlings have yet to fledge. Even that must be
considered, said John Zediak, chief of the corps' water management
section. "Many considerations must be weighed: flood control, water
supply irrigation, environment, saltwater intrusion," Zediak said.
"We are trying to continually manage in a way to balance those
Lately, the question of preserving the wells has taken precedence.
"That's where the need is," he said.
This time last year, the concern was flood control: keeping the
Herbert Hoover dike around Lake Okeechobee safe from a hurricane.
Fresh water from the lake was sent out to sea to lower the lake and
reduce the risk of dike failure going into hurricane season.
The storms didn't come, and now the lake is too low.
"Mother Nature, she'll give us rain or she won't give us rain,"
Zediak said. "I can't really tell you what the future is going to be.
I can try to manage the resource to the best of our ability."
Temperature plots for many U.S. climate stations