MSD warns public to avoid part of Meramec River

[SpoonDog]

The Valley Park gauge was 4+ feet above the previous record and 12+ feet above the 1993 level at 12/31/15.  The term "100 year" and "500 year" flood doesn't reflect the frequency of the event, the chances of either happening in any given year are basically the same and they don't accumulate- whether you're 5 years since the last big flood or 400 years from the fast big flood, the chances of it happening the next year are the same.  The only thing that really reflects the frequency is folks building higher levees that prevent the river from spreading out onto its floodplain, so that the only place for the water to go is up and over. 

 

Trust me, a big flood can happen back to back to back on the Meramec, like in 1993, 1994 & 1995, carrying away promising little-league careers in the process :).

[Born to Fish]

I try to avoid skin contact with most waters in the state of Missouri. There's just too many cows, pigs, chickens, turkeys, geese, and humans, to name a few, fertilizing these waters anymore!! 

[fishinwrench]

1 hour ago, Born to Fish said:

I try to avoid skin contact with most waters in the state of Missouri. There's just too many cows, pigs, chickens, turkeys, geese, and humans, to name a few, fertilizing these waters anymore!! 

When my skin becomes too sensitive or the water too polluted, and nobody cares enough to clean it up, then it is time for me to cash in my chips.  

[jdmidwest]

There has been poop in the water longer than there have been fish in it.  It will dilute itself out next big rain.

I think what made this flood monumental was all of the tributary flash flooding running into a swollen Mississippi.  93 was from flooding upstream on the Missouri and Mississippi backing up and spilling out into the Mississippi flood plain.  This time, most of the water locally came from local streams like Meramec and others.

[Al Agnew]

Yeah, there should be a different designation of floods and levee designs.  A 500 year flood means there is a 1 in 500 chance of having a flood that high in any given year, not that there won't be another one for 500 years.  A 1000 year flood would be a 1 in 1000 chance of it happening in any given year.  Point to take from that is, no levee, no matter how high, will protect from any possible flood.  And as has been mentioned, building more levees just means the river has less room to spread out, and therefore will go higher, so the more levees you build, the more chance there is that a flood will overtop them.  What was once a 1 in 500 chance suddenly becomes a 1 in 250 chance...which means it doesn't take as much rain or as much volume of water to go higher.  Plus, weather runs in cycles, and it's not unusual to have several wet years in a row and several huge floods in a row.

Every sewage system is built in a flood plain, seems like.  Simple to see why...the lower it is the less need there is to pump the water into it.  Not to mention that flood plain land is cheaper to buy and develop.  But since that's the case, to really protect against stuff like this, you need to build a flood wall around it that's twice as high as you think you'd ever need, or else site it in an area where there are no other levees and plenty of room for the river to spread out, and then zone the whole area for nothing but agriculture and make it impossible to build any other levees in the area.  But we've never been smart when it comes to flood plain development.  In fact, we've been downright stupid, and I see no chances of that changing in the foreseeable future.

[moguy1973]

I wonder what happens when the Chesterfield Valley levee is breached after they've spent billions of dollars to build all that area up since the flood of '93.  It's bound to happen.  And probably in our general lifetime.

[Mitch f]

7 hours ago, moguy1973 said:

I wonder what happens when the Chesterfield Valley levee is breached after they've spent billions of dollars to build all that area up since the flood of '93.  It's bound to happen.  And probably in our general lifetime.

That'll probably be the only time I'll be able to get a Table at Annie Gunns ?

[mjk86]

7 hours ago, moguy1973 said:

I wonder what happens when the Chesterfield Valley levee is breached after they've spent billions of dollars to build all that area up since the flood of '93.  It's bound to happen.  And probably in our general lifetime.

I thought the same thing.  Just doesn't seem wise to me.  Like everything else I guess.....if there is money to be made in short term go for it.

[SpoonDog]

13 hours ago, moguy1973 said:

I wonder what happens when the Chesterfield Valley levee is breached after they've spent billions of dollars to build all that area up since the flood of '93.  It's bound to happen.  And probably in our general lifetime.

Exactly- putting ball fields in a river bottom is one thing, but building a Maserati dealership seems to be just asking for God's wrath.  If there's a bright side it's that feds and state agencies bought up a fair bit of MO river bottomland after the 93 and 95 floods and that may allow the river to spread out more- but more likely those re-built levees will be overtopped at some point and folks will wring their hands calling it a tragedy.

[snagged in outlet 3]

Lived here all my life and have watched this over and over  

Don't build in the flood plain.

Thats why they call it a FLOOD plain. 

If you do, don't look here for sympathy. 

Pete