Drawing Down the St. Johns

SJRSunset The Saint Johns River Water Management District (SJRWMD) will meet Monday to vote on a Seminole County proposal to withdraw 5.5 million gallons of water per day from the St. Johns rivers.  Seminole County says they need the water to meet demand for water caused by growth in the region.  The county says it will use the water primarily for irrigation though some would be processed for drinking water.  The county has designed a facility that could eventually draw up to 50 million gallons daily from the St. Johns river in north central Florida.

Duval county officials are on record as opposing this withdrawal.  Environmental scientists say there has not been enough study on the possible effects of increased salinity of the river should hundreds of millions of gallons of fresh water be siphoned off and not allowed to make its way north to the ocean.

The St. Johns is not like the great inland rivers I grew up with.  The nearest to me was the Ohio, which forms the southern border of Indiana.  Water in that river moved steadily one direction … south and west to the Mississippi and eventually to the  Gulf of Mexico.  It rises and falls with annual rain and runoff, not with the tides.  The similarity is that it provides commerce and recreation to millions of people, as does the St. Johns.

But the St. Johns River is tidal.  When the current and the tide both flow to the north, it races along at several knots, and I’ve seen sailboats struggling to makeGulls on Posts their way up river against the flow.  But on an incoming tide, the river flows back to the south … bringing salt water from the ocean far up stream.  The further south, the more fresh the water, due to the natural springs and watershed that feed the upper, southern reaches of the river.  No one knows how the withdrawal of millions of gallons of that fresh water will effect that salinity, and how much further south salt water will intrude should that northern flow of fresh water be depleted.

That water is needed to flush out the St. Johns.  It flows slowly, with a total drop in elevation of only 30 feet over it’s 310 mile length.  Along the way, the watershed drains a huge area of Florida, much of which is developed.  That means a lot of nutrients running off fertilized lawns, golf courses, and the like.  The only way those nutrients can be removed from the river is if they’re flushed out by the water flow.  The water flows slowly anyway, and goes back and forth with the change of the tide.  Several years ago, the river was choked in several places by a blue-green algae that was attributed to an elevated level of those nutrients.

Then, too, there is the salt water intrusion.  The river has decreasing levels of salinity as you travel to the south.  The grasses and other aquatic plants which shelter the marine need certain levels of salinity to thrive.  Too much, and it can change the entire ecosystem of the river.

Now, I’m not marine biologist, but it doesn’t take a lot of research to learn these things. MathHart1

In the not too distant future, dredging will begin on the St. Johns from the mouth of the river to Jaxport’s Blount Island facility to accommodate the larger,  post-panamax ships that call here.  It’s very important to the region’s economy, but deepening the river will also allow a greater volume of salt water to make it’s way upriver.  But not accommodating those post-Panamax ships would put our port at such a competitive disadvantage that there’s very little doubt that it will be done.

But the water withdrawal is a little squishier.  It’s for irrigation at a time when mandatory water restrictions are in effect over pretty much the entire state of Florida, and for drinking water for an expanding population.  Growth has been such a huge issue for 40 or more years in Florida, and it has not always been as well planned as it might have been.  Still, an Administrative Law Judge has given his approval to the withdrawal plan, but there is an ongoing scientific study into the potential effects of withdrawing that much water.  Meanwhile, Seminole County is just the beginning.  There are proposals to withdraw as much as 262 million gallons per day from the river.

The meeting begins at 1:00 pm at the offices of the SJRWMD. The St. Johns Riverkeeper is planning to take a bus of people to Palatka.  Public comments will be heard.  For me, the question that has to be answered is: should the ecosystem of the river be potentially  jeopardized for green lawns in Seminole County?  We don’t know for sure that it will, but we don’t know for sure that it won’t either.  I would urge the water management district to not allow the withdrawal to begin until those and other questions about the ecosystem are answered.




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Filed under St. Johns River, Thoughts, Water Withdrawal

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