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Are there different permanent datum references for lake and river level measurements? For instance the present level of the Red River at Shreveport is 37 feet, but the level of Lake Bistineau (now basically the same as the Red River) is around 175 feet. I assume one is mean sea level, and one is something else. Please enlighten me.
The ones I look at are the Vermillion River at Carencro by my house on the bridge and at Toledo Bend. Both based on MSL, which all should be. The Red River at Shreveport apparently (to me) is a level above either full pool or normal stage - don't know. Those folks may do that not to confuse the general public.
It would make more sense ( to me ) to just use msl for everything.
Rivers are measured in actual depth at a location (Shreveport is the railroad trussell)
lakes are measured at sea level
I use the USGS website for viewing the Vermillion gauge since they are the one's that maintain it. They utilize the NAVD elevation such as in today's elevation:
Attachment 205945
The North American Vertical Datum (NAVD) 1988 is based on orthometric height. Informally, this could be considered as a height above mean sea level (MSL).
George, here is the Red River in Shreveport at the USGS website at both datum's:
USGS Current Conditions for USGS 07348500 (COE) Red River at Shreveport, LA
Interesting that they use the NGVD which was superseded by the NAVD for MSL elevations. Same general information unless calculations are critical. Like you, I look at both river and lake elevations. So, it's easier to keep the same datum when I look at such things - just me.
Thanks Buster and Randy for the replies. I had run across a paper from Tulane last night that stated that most, but not all, rivers use a locally defined reference point.
Lot of folks along the Red still have a long way to go before this is over.At least at Shreveport/Bossier the crest finally arrived and it can start to fall.