Here are some Fall Turnover reports from Paul Mauck. He also explains the smell at the Dam is because the lake has not turned over.  I thought might be helpful to those who do not understand Fall turnover and to those that do fishing the BASS event.

These reports are posted on the six old geezers web site

(This report is from 2002)

I had asked Paul Mauck, Southcentral Region Fish
Supervisor, to give us a report on the "lake turnover".
The following reports are provided by the
Oklahoma Department of Wildlife Conservation,
Southcentral Region Fisheries Personnel. I wish to thank Paul for the following reply.

Your questions regarding how and when the water in Lake Texoma
"turns over" is often asked by many people and is not understood
by many folks. A lot of people believe that during the summer time
when their drinking water ( if it comes from a lake or river) begins
to taste and smell "lakey" for lack of a better term, that the
lake is turning over when, in fact it is probably related to algal
blooms and a general decline in water quality.

In most southern climates where lakes do not freeze over for an
extended time only a fall overturn is experienced each year.

Typically Lake Texoma stratifies in late spring (late May or early
June) at which time the warmer upper water layer does not mix with the
lower cooler water level. During this time the oxygen below 40 or 50
feet is used up. Often anglers using juglines or trotlines set in
deeper water will find dead fish on their lines during this time.

Anglers that are fishing for striped bass usually will observe fish
concentrations in the thermocline ( the area of water just above the anoxic
zone ), usually around 35 - 45 feet deep. Texoma usually stays stratified
until the last week of September, when the fall weather change begins.
As the temperature of the upper layer of water cools and approaches
the temperature of the lower layer, accompanied by strong wind action,
the entire lake begins to circulate and the lake "turns over".

Water, that has remained trapped in the lake depths all summer, again
comes in contact with the surface layers where free and dissolved carbon
dioxide has an opportunity to escape and the dissolved oxygen supply is
replinished.

Following the renewal of oxygen in the lower levels fish can again
inhabit the entire lake from top to bottom.

Another simple way to know if the lake has destratified, is to visit
the area of the Red River below the dam. If there is no sulfide smell
from the lake water discharge, then the lake has probably turned over.

Note: The lake oxygen level was checked on September 26th, and the
lake had turned over as of that date.

The following two charts show the tempature and oxygen contents at
various levels taken on September 26, 2002 and August 7, 2002.

2004 Report

(This report is from 2004)

I had asked Paul Mauck, Southcentral Region Fish
Supervisor, to give us a report on the "lake turnover".
The following reports are provided by the
Oklahoma Department of Wildlife Conservation,
Southcentral Region Fisheries Personnel.

Southcentral Region Fisheries personnel took water profiles (oxygen and
temperatures) at one meter increments at two locations ( in front of the
dam and just south of the railroad bridge) today, September 16, 2004. The
lake is currently stratified (has not turned over) but appears to be close.
Oxygen levels suitable for survival of fish (levels of 2 or greater) were
better near the dam. In fisherman terms (shad could live to approx. 70 ft.
deep at the dam but only to approx. 40 ft. near the RR bridge. Water temp.
varied from 76 F at the surface to 74 degrees F at 90 ft. at the dam vs. 78
F at the surface to 75 degrees F at 75 ft. at the RR bridge (see attached
water temp./dissolved oxygen profiles). When the water temperatures
equalizes from top to bottom the waters will mix and the lake will be
destratified. Then fish can live at whatever depths they desire. This
normally occurs near the end of September of each year. Usually it
coincides with the arrival of the sea gulls (give or take a week of
Sept. 21. according to my observations).

Hope this info. helps answer some questions. Better fishing is not far off.

Paul Mauck
Fisheries Biologist
Okla. Dept. Wildl. Cons.

Thank you Tim, great info