Olmos Basin Park - Lowest water area in San Antonio? (Devine: 2013, hotel)

[OzzyRules]

Do you think that Olmos Basin Park is the lowest water area in San Antonio?

It always seems to get completely submerged during the big floods we have had. Like the one yesterday (Saturday May 25, 2013) or the one in 1998?

Does it ever get submerged at other times?

Whenever I drive past the area on Devine Road, it always seems so lush and green compared to the rest of San Antonio. I'm not even sure I would want to venture into the walking trail I've seen near the OBP sign near Devine close to where it passes under 281 (just a little north) because I can only imagine the spiders or other creatures that exist in that area. It makes me wonder if it is actually (1) underwater or (2) in a "swampy" condition a lot of times, even during more normal rains.

Thanks for any information.

[Bo]

It's in a flood plain. That's why there's a golf course on that land instead of a subdivision or shopping center.

Think about what a prime commercial or residential location that would be if it were developed. If it could have been developed, it would have. But it's needed for flood control.

[flourpower]

Hence the need for a dam.

[RedNeckRick]

As Bo said, It is a flood plain and is intended to flood, due to the dam that was built after the early 1900's flood that decimated downtown, to hold back the flood waters from Olmos creek and be released slowly so not to cause catastrophic damage to the downtown area.

[TrapperL]

This is why we have the Olmos Dam and the Olmos Flood Basin.
St Marys and Navarro


St Marys St. You can see the water line on the building. Probably got to about 8feet deep in downtown SA. My grandfather said it got up into the second story of the hotel he was staying at.


Travis St. All dated Sept 10, 1921

[WilGar]

To answer the original question, the Olmos Basis is not the low point in the runoff of flood waters. It is a "catchment" to avoid or minimize flooding downstream.

Consider that San Antonio International is 809' and Stinson is 577', that is a drop of 232' from the north side to south of downtown. Consider all the runoff from the downpour and flooding is inevitable.

The Olmos Dam prevents in small rain instances, and slows in heavy rain instances, such as we had this time, the deluge going down stream. It can not prevent, nor was it designed to prevent, all flood water from going down stream.

Does anyone else remember the city councilman during the 1998 deluge accusing the city of releasing flood waters to submerge his district? The accusations are happening again.

The dam is to contain and, in so doing, must systematically release the water. The greatest fear is a topping of the dam; thus waters are released to keep the flood waters contained by the dam and prevent that disaster.

[huckster]

Most locations on the north side are well over six hundred feet above sea level
there where the Hill Country begins Wil Gar, you are right. Some higher.
There are flood control dams built from limestone all over the north side outside Loop 1604. One near 1604 and I-10 and another on the southwest intersection of 1604 and Culebra where Leon and Culebra Creeks intersect.
I have pictures of these... floodwaters used to tear through really bad around here years ago before these dams were built.
If you go for a hike there off Culebra Rd. , down in the riverbottom you will find what looks like a
paved concrete two lane street 200 feet long fifty feet in the air , in the middle of nowhere. The pavement is the top of a diversionary dam down there to form a temp. flood water retention pond.
I found a mamoth's tooth in that dry creek bank one time , that I still own.

Originally Posted by WilGar

To answer the original question, the Olmos Basis is not the low point in the runoff of flood waters. It is a "catchment" to avoid or minimize flooding downstream.

Consider that San Antonio International is 809' and Stinson is 577', that is a drop of 232' from the north side to south of downtown. Consider all the runoff from the downpour and flooding is inevitable.

The Olmos Dam prevents in small rain instances, and slows in heavy rain instances, such as we had this time, the deluge going down stream. It can not prevent, nor was it designed to prevent, all flood water from going down stream.

Does anyone else remember the city councilman during the 1998 deluge accusing the city of releasing flood waters to submerge his district? The accusations are happening again.

The dam is to contain and, in so doing, must systematically release the water. The greatest fear is a topping of the dam; thus waters are released to keep the flood waters contained by the dam and prevent that disaster.

[StanStelle]

Why is 281 still underwater as of this morning? I've been looking at pictures to see if it is just a low point in the highway or is it floodwater that reached all the way to the dam and now started backing up to lower elevations which just happens to run by Hwy 281 & Basse?
Here is a picture from the Express News: http://ww1.hdnux.com/photos/21/67/70.../7/628x471.jpg

Here's a Google Street View of the afflicted area: https://maps.google.com/maps?q=basse...180.83,,0,7.02

It seems there are some lower pockets to the right as you're going southbound on 281. Were these meant to catch water and when they fill up they flow over the highway or is it just backed up water from Olmos Dam?
It seems the regulated release of water from the dam is the only way to get the water off 281?

Either way, it seems this portion of the highway should have been built a lot higher.

[L210]

It's still closed? It looks like I'll be taking IH-35 to work for a little while longer.

[TrapperL]

I don't think you understand just how large the catchment area is. It's over 33 square miles. Lots of water run off. It extends past the airport to near 1604. Here's the dam after it was completed before we turned most of it to concrete and asphalt which adds to the issue.


If you are at the dam and can look north, you'd see where the waters from a large area are funneled to this small opening. As the water builds in height, it builds in speed which caused all of the damage in previous floods. There's a lot of water that naturally drains via the Olmos Dam.