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Why are Hernando and Pasco lakes so dry?

We seem to be just about done with the drought.

The aquifer is back to a normal level. So, for the first time in years, is the Withlacoochee River. There has even been talk recently at the Southwest Florida Water Management District of lifting restrictions and allowing homeowners to resume watering their lawns twice a week.

So how come, when I walked down to the shore of Lake Theresa at Delta Woods Park in Spring Hill on Thursday, all I saw was grass, weeds and scattered, shallow puddles?

What's the explanation for that same view at Crews Lake Park in Pasco County?

True, I did see actual rippling water in Hunter's Lake, in the southwest corner of Hernando. But why was it only visible beyond another expanse of weedy former lake bed and the padlock blocking access to the Kenlake Avenue boat ramp, which has been closed since August 2007 due to low water?

Here's Swiftmud's answer to those questions:

First of all, the district hesitates to make official declarations about the end of the drought, and lakes are always the last bodies of water to recover.

"They are a lagging indictor," said Granville Kinsman, the district's hydrologic data manager.

That's especially true of lakes such as the ones in western Hernando and Pasco counties, with sandy, porous beds that don't stay full unless there is groundwater beneath them.

Remember, also, this drought has lasted nearly five years, Kinsman said. And even though rainfall in most of the district was normal much of last year and above normal this winter, look back even two years and you will see deep rainfall deficits.

"We've had consistent rain, but we haven't had anything extraordinary," Kinsman said Thursday (a few hours before one of those downpours that always seems to arrive as soon as we commit to writing about a shortage of water).

Everything he says sounds reasonable and is, I'm sure, based on good science. Still, I can't shake the feeling that something scary is going on with our bodies of water.

The Withlacoochee, as I reported last fall, has been far more prone to extended low levels in the past two decades than it was before that time. The declining levels in many lakes may be even more dramatic, as you can see from the eye-popping graph that accompanies this column.

It shows the average water level in Swiftmud's northern lakes — a category that includes every one in Hernando and several in Pasco — along with their historic levels as established through studies of wetland vegetation and other natural features.

The average level of these lakes has hovered well below the normal range for most of the past 13 years, and climbed into the normal range only after what most of us think of as highly abnormal rain events, including the record-breaking El Nino years of 1997-98 and the multiple tropical storms of 2004.

If you've lived here long enough, this probably corresponds with what you've noticed over the years.

When my oldest son was a toddler, my father-in-law took him canoeing several times on Crews Lake. He's in high school now, so almost all of his childhood has passed with only a few more chances for canoeing, and with Crews almost always looking more like a field than a lake.

"They've got a dock (at Crews Lake) that never sees water," said Frank Bourgeois, a Spring Hill fishing guide who has worked in Florida since 1980.

Though some say this may in fact be a fish story, it is believed that Big Fish Lake in Pasco once consistently held enough water to nurture a 20.13-pound largemouth bass, which set an unofficial state record when it was caught there in 1923. Look at a graph of the lake's water levels and you'll see the same general pattern as the regional average: other than a couple of dramatic spikes, far below average water levels for most of the past 15 years.

"I've never even heard of Big Fish Lake," Bourgeois said.

Though he makes it clear he's just a guy who spends a lot of time on the water, and not a scientist, he thinks pumping for development is responsible for the falling water levels.

That's not the case, according to Swiftmud.

Two years ago, when the district established the minimum water levels needed to maintain the health of the Spring Hill lakes, it estimated that less than a foot of their decline was due to withdrawals. Also, a Swiftmud scientist pointed out at the time, lakes in eastern Hernando, an area where far less water is removed from the aquifer, have been just about as low for just about as long.

Except for a small mud puddle, Bystre Lake dried up last year for the first time in memory, said Hernando County Commissioner Jim Adkins, who lives on its shores and watched cattle graze in its bed. There still isn't enough water in the lake to allow fishing, said Roy Link, Hernando's parks and waterways maintenance supervisor.

That leads to another puzzle. The beds of most lakes in eastern Hernando are richer in clay, meaning they should hold more rainwater, and should have rebounded more quickly than the ones on the west side of the county. Kinsman said hidden sinkholes appear to draining some of these eastern lakes.

Regardless, he said, the overall culprit for low lake levels in recent decades is low rainfall, which he hopes is just part of a temporary natural cycle.

"I would definitely hesitate to say this is a permanent thing," Kinsman said.

Of course he doesn't know that for sure and, given the complexity of long-term climate changes, I'm not sure it's fair to expect him to.

But I think looking at this issue should be one of the district's top priorities.

Because if the root cause of shrinking lakes is uncertain, this is not: Full, healthy lakes could do a lot to make Hernando a better, more marketable place to live. Look back at the original 1960s advertising brochures for Spring Hill and you might be surprised at all the images of speed boats, water skis and youthful-looking retirees holding strings of bass.

These lakes have been gone, or almost gone, for so long, I'm not sure we even realize how much we miss them.

Why are Hernando and Pasco lakes so dry? 03/27/10 [Last modified: Saturday, March 27, 2010 3:37pm]

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