There’s hope on the horizon as El Niño is expected to strengthen, bringing unseasonably heavy rain to Florida during the typically dry winter months. If it fails to materialize, though, Tampa Bay may be in for its worst drought ever because the region’s lakes, rivers and aquifers are only slightly above where they were when the rainy season started in June.
But this year, we have an ace in the hole – the C.W. “Bill” Young Regional Reservoir has nearly 14 billion gallons of water stored in it. Last year at this time, it was nearly empty. New studies showing the cracks in the reservoir posed no danger to nearby residents allowed Tampa Bay Water to take advantage of heavier than normal rains in May to skim additional water from the Alafia River. In December, the Southwest Florida Water Management District eased water restrictions from extreme to severe because Tampa Bay Water had made substantial progress in reducing its groundwater withdrawals.
Although the utility exceeded permitted levels for groundwater pumping this spring, they set a new daily record low on Nov. 14 of 39.92 mgd. Even at their worst, a daily peak of 143 mgd per day in March, it’s still far less than the average 153 mgd pumped every day in 1996.
Pull up a chair and listen in as we pose questions about the current drought and the long-term plans for water supplies to the people who live and breathe them. We’ll start with Granville Kinsman, SWFWMD’s hydrologic data manager.
Q: How far below average rainfall are we for 2009 and how does that compare to recent years?
As of the end of October, the 12-month deficit district-wide is 6.7 inches and the 36-month deficit is 21 inches. The 21-inch deficit is essentially unchanged from the end of the dry season – that is, we didn’t see any improvement during our rainy season. Of course, we didn’t get the above-normal rainfall that was predicted for the summer. The 12-month deficit improved only slightly in September, every other month it increased.
In fact, if it weren’t for the extreme rainfall that we received in May, we would not have seen the improvements to streamflow that allowed Tampa Bay Water and Peace River Manasota Water Supply Authority to refill their reservoirs. They weren’t able to fully fill them, but they did maximize capture of water to fill them as much as possible.
Lakes are a good indicator of rainfall deficit. This summer we saw the best improvement in the northern and Tampa Bay lakes, but they never returned to normal levels (Tampa Bay lakes reached the very bottom of their annual normal range in September, but have again fallen below normal). The bottom of the normal range correlates to levels we should see at the end of our dry season in May, not end of the wet season. By mid-November, the lakes in the Polk Uplands and Lake Wales Ridge regions had already lost approximately half of the water level rises that they gained during the summer.
Q: How long has this drought lasted and how does it compare to earlier severe droughts?
If you use 12-month rainfall as an indicator of drought, the current drought has lasted 43 months. That has only been exceeded one time since our record began in 1915 – the period from February 1999 through November 2002, a period of 46 months. Although we haven’t experienced the extreme rainfall deficits this time that we saw during the ‘99-‘02 drought, the duration has taken a toll on lake levels, streamflow, and ground water levels. Lake levels in May 2009 in the northern region reached the same lows recorded at the height of the earlier drought.
Q: Which areas of the district are faring the best?
The central counties of the district, particularly the Tampa Bay area, saw the best improvements in lakes, streams and groundwater, although all indicators are either below normal or headed sharply downward. The upside is that sufficient surface water was available to very nearly fill the C.W. “Bill” Young reservoir, and also the new Peace River Reservoir 2 in Arcadia.
For a look at the more-distant future, we talked to Paula Dye, the TBW’s project manager who directs the long-term planning process at the regional utility.
Q: Tampa Bay Water completed an updated master water supply plan in late 2008. What’s included in that proposal?
We identified potential project ideas to evaluate for long-term water supply needs. Along with that, the board also adopted a source water protection plan and an updated demand management plan. We’re very, very fortunate that our member governments have been pro-active in conserving water. The statewide average per capita water usage is 160 gallons per day. In Tampa Bay, it’s 109.
Demand has flattened so we actually have more time to look at projects for future needs. We’ll continue to plan in five-year cycles but we probably will continue further evaluation of the projects in this plan in 2013. We’re also planning for climate variability and more severe droughts that we’re already starting to see.
Q: What new sources are likely to come online in the future?
We’re moving ahead with small footprint RO (reverse osmosis desalination) plants in Pinellas County. We have a new in-house project engineer who is monitoring efforts in Oldsmar and Tarpon Springs. We also are looking at expanding the desal plant at Big Bend and building the Gulf Coast desal plant adjacent to the Anclote Power Plant in southwest Pasco County. We’d done extensive studies in the early 2000s on the new plant, including a year of pilot testing. We’ve got some more in-house work to complete, including coordinating with Progress Energy, but it looks like it’s something we can do very successfully.
We’re looking at some additional groundwater over the very long term. The Thonotosassa wellfield is owned by the City of Tampa. We’re working with them on some of the contractual requirements they have and the land agreements we need to have in place to use the property.
Q: Aquifer recharge wasn’t part of the plan in 2007, but it’s there now?
It wasn’t on our screen in 2007 but in 2008 the district did a very thorough study of aquifer recharge and as a result of that, we added the idea to our list of projects to evaluate. We’ll start looking at specific projects next year.
Q: What about the reservoir?
The reservoir is the work horse of our water system. It’s got nearly 14 billion gallons of water in it now that should get us through the dry season. It’s very important that we do the long-term renovations but the cracks are not a safety issue. We’re looking at the siting for a second reservoir now. It’s been narrowed down to four sites, but we’ll probably defer it for three or four years with the flattened demand. We’re also looking at the possibility of expanding the current reservoir while we’re doing the renovation.
Article originally published Winter 2010.
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