The Phatwater, today, on the Natchez gauge, registers at 39.25′.  The gauge, for those who have a “need to know” is located somewhere on one of the bridges which span the Phatwater from Natchez to Vidalia, La.  The gauge is at mile 363.3, as measured upstream from mile zero.  Mile zero is located at “Head Of Passes”. Head of Passes is the nominal “mouth” of the Mississippi River, down yonder, below Venice, Louisiana, some 10.8 miles.  Head Of Passes forms the “Birdsfoot Delta”, comprised of Southwest Pass, South Pass, and Loutre (East) Pass, as seen in this exceptionally-well-funded NASA archive image:

I don’t know when this image was captured, but something tells me it was well before the British Petroluem-White House arm wrestling began in earnest.

But, some of you may wonder, as I still do, “What does 39.25′ on the Natchez gauge actually mean?”

Seek and ye shall find.  I sought, and found this, as explained by Tim Rodgers, P.E., with the Corps Of Engineers:

Mr. Benoist,

Each gage has a gage zero which when added to the gage reading gives you an

elevation which is roughly related to mean sea level.  Most of these gages

were converted to this system in the early 1900s.  For example, the

Mississippi River at Natchez has a gage zero of 17.28 feet which you would

add to the gage reading to get an approximate sea level reading.  Over time

and with technological advances in surveying, the system has been updated.

It is now referred to the National Geodetic Vertical Datum which is

established and maintained by the National Geodetic Survey -

http://www.ngs.noaa.gov/.  The particular datum for a gage was set at the

lowest recorded gage reading of record at the time.

Tim A. Rodgers, P.E.

Water Control Management

Vicksburg District

CEMVK-ED-HC

4155 East Clay Street

Vicksburg, MS 39183

Phone: (601) 631-5669 Fax: (601) 631-7231

Email: Tim.A.Rodgers@usace.army.mil

This information was provided by Tim last October, just before the Phatwater, but I don’t recall posting it at that time.  It was confusing to me then, and is confusing to me now.   If I did post it, none of you engineers in our mix, and I know there are many, bothered to comment. Why? Because you’re sissies!

In any event, I don’t remember if I posted the info or not.  Perhaps by posting it now, one of you engineers out there, and I’m thinking of someone from Milwaukee, will un-sissify yourself and offer a more cogent explanation.  The door’s always open, good citizens.  Protest me.

Still planning for a Saturday Halph-Phat for anyone interested in shuttling with us.  We’ll be leaving the UTH area at 0600.  Shuttle fee is $20 per paddler, ducks and nutria exempt.

All For Now-KB