Army Corps of Engineers: deficient levee list

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yzer

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This page takes you to the Feb. 1, 2007 Army Corps of Engineers (ACE) press release listing the nation's top deficient levees. The actual list is a linked PDF near the bottom of the page. California levees begin near the bottom of page 2 and take up almost all of page 3.

http://www.hq.usace.army.mil/cepa/releases/leveesafety.htm

Our boat is on Lower Andrus Island facing the San Joaquin. There was a lot of levee work done there during 2006. [^]

Here is an ACE map showing California Delta zones that flooded during the last 40 years.

http://www.spk.usace.army.mil/organ.../delta_reports/Plate 1 Delta Flooding Map.pdf

Here is where ACE is has focused "high priority" problems:

http://www.spk.usace.army.mil/organ...rts/Plate 3 Map of Priorities of Projects.pdf

Here is the site for Sacramento area ACE local activities:

http://www.spk.usace.army.mil/
 
Wow, the real impact is when you consider that is only, only, the last 40 years.
 
Yep. Some of the tule berms in the Delta are all that remains of old levees. After a break it was easier sometimes to make a new levee by sacrificing a little land and making the new one in back of the old.
 
Or leave it flooded, like Franks Tract, Little Mandeville, and Rhode Island.

I saw a TV report on this survey. They said that any levee which could not be completely visually inspected got a failing grade. That means all trees, bushes and grasses must be removed to pass. And if it doesn't pass and the levee breaks, no federal funds will available for victims or repairs.

How is erosion from rains and high tides to be prevented w/o even some grass on the banks???? And how ugly with they all look! Can imagine Georgana Slu if it is barren????? But folks seem to have no choice.

I think this approach by the Corp of Engineers is all wrong or the media is misreporting the facts.
 
Flood control and nature are sometimes at odds with each other. Old photos of the Delta taken back in the fifties and earlier tell the story. All of those treeless, riprapped levees along Delta sloughs were lined by trees and dense growth in the old days. As the trees grew, matured and eventually died; they fell over taking chunks of the earthen levees with them. Trees have a habit of falling over at exactly the wrong time, like during a heavy storm. Sometimes root systems simply decayed leaving voids in the levee to leak and cause failures.

Grasses are usually not a problem. They are a big help in reducing erosion. Some districts run sheep on grassy levees or mow a few weeks before the inspection team arrives. That's fine with ACE.

One solution that provides safe levees and habitat at the same time are setback levees. Setbacks allow space for trees, bushes, grass and critters between the waters' edge and the levee bank. This approach is benficial for pelagic species as well. But, building a setback levee requires some expensive engineering with less than immediate benefits as a result. That's not the engineering we have on most private levees. Some are over 100 years old and sit on a foundation of compressed peat.

I won't try to speculate about what problems ACE is trying to fix. I don't have the details. I haven't heard the levee districts' side of the story, either. Each district has its own set of conditions and problems.

After hurricane Katrina and our high water a year ago, everyone wanted to get the levees fixed. The time to fix the levees has arrived. Restoring the Delta's natural environment will cost still more, and that issue hasn't been fully addressed yet.

Now that President Bush has decided that global warming is real, I guess everyone has to consider the problems we may encounter in the not-so-distant future. There are a couple of global warming effects predicted for the California Delta. Sea level will rise slightly putting more strain on the levee system. Storms will become less predictable and stronger. The state must be prepared to move large amounts of runoff out of the system quickly. Right now the Delta is the weak link in that system.

Remember how stressed some levees were with the New Year's storms last year? That was nothing compared to what happened in 1986 or the storm systems we will get in the next decades.

I'll never forget 1986 when I stood on the back levee of the American River at Watt Avenue and saw the river a few feet from the top. Or when I drove home that afternoon and saw water from the Yolo bypass splash over the causeway guard rail and onto I-80.
 
Yzer, it sounds like you are well informed and have better information then a 3 min TV interview. Thanks for helping us to stay informed.
 
Yes, 86 was something else. I had just put my boat in the water at Folsom Lake Marina. The water was low, just above the winter elevation of 425'. The next day I called Ken Christiansen, the manager/operator and he said my boat was not in any danger, but most of the boats that were still on there trailers in the parking lot where in danger if the lake came up any more. I rushed out to the lake, and the water level was at 466', the fill point. That is 40' of water overnight. Many of the people in Sacramento and downriver of Folsom dam, have no idea how close they came to disaster. Funny thing is that most of them are opposed to the Auburn dam. If it happened once, its going to happen again.
 
It seems to me that the man made islands in the delta may have outlived their viability.

There are many areas where the levees are protecting massive areas, or areas that are densly populated and these levees should be getting a lot of attention. But a large portion of the "high priority" areas are farmland that I frankly don't see the value in spending taxpayer dollars to keep up.

They say that global warming is going to raise sea level and there is nothing we can do to stop it. How high sea level raises seems to be in dispute, some reports say 6 inches while others say a few feet. I look at a lot of the levees at high tide, add three feet and see a massive problem!

Back when the levee system was built the delta was PRIME and essential farm land. Without extensive irrigation systems the delta was a much needed source of water for the crops. Without freeways and 18 wheeler trucks the sloughs provided transportion. Today it seems that we might be struggling in a vain attempt to fight mother nature.

Another interesting aspect of the levee system is that the land on the "dry" side has fallen over the years. I forget the exact numbers but the elevation of the ground has dropped a fair number of feet over the years since the tracts were first created. The dry side is getting deeper, the wet side is getting higher, the strain on the levees has got to be getting enormous.

When Jones tract flooded a couple of years ago it happened at a fairly un-exceptional time. The levee wasn't breached, it didn't fail because water flowed over it, or break through it. It failed because it was undermined, a leak path developed under it. The failure didn't happen on the highest of tides, or during a storm, or during exceptionally heavy runoff.

I wonder what would happen if we were hit by a massive tropical storm in early April, centered on the day of the highest of high tides. A very wet storm that would drop a lot of rain on its own, and a warm rain that would rapidly melt the Sierra snow pack. Add to that even a slight raise in sea level and it seems like the current levee system is doomed.

Some areas we need to fix. But some areas I believe we need to let go as they have outlived their usefullness.

Rod
 
Quite a few of the Delta Islands are very productive farmland. Some are successful corporate farms that have no intention of pulling out. Its difficult to justify flooding all Delta islands that have become unproductive because environmental effects of island flooding are not fully understood. There are a lot of studies going on right now, though.

Take Franks Tract as an example. It's too deep to return to its original tule state, deep enough to screw up the saltwater intrusion situation, and shallow enough to grow a lot of underwater invasive species weeds. The shallow and warmer water adds more mercury compounds to water that is piped south for drinking and agriculture.

The thinking now is that a wholesale flooding of Delta islands will make more problems than it solves. Some dry islands may be deliberately flooded and some flooded islands may get drained or partially leveed.

The islands are subsiding, but the rate varies from island to island. Different soil types play a role, too. I think the lowest island point is something like 33 feet below sea level, but I may be off on this.

A lot of peat was simply cut out, bagged and sold in stores around the world as potting soil. Plowing the soil causes some loss to wind, and oxygenates and drys the high organic content, causing the top soil layer to actually shrink. You are right, subsidence is a process that will continue as long as the islands are plowed.
 
Many of those delta islands are planned as future housing developments, so the levees need to be maintained and improved or the developers told "no". Fat chance of that happening!

You should go to Bethel Island by car and see all the dirt which has been hauled in to build up the new Delta Coves project! I think the new levee must be 20 or more feet higher then the island's "ground". There are rumors that broaching the current levee to fill the basin is going to make BI a floating island. The peat will be floated off of the bottom underneath. Guess we will know in a year or two.
 
In the Pineapple Express storm of 1997 which sent torrents of melting snow down through the delta along with the storm's rain, what saved the delta were the flooding around Yuba City, Wilton and Lathrop. Also there was no wind to overtop the levees. I watched the water come within inches of the top of the levee at Bethel Island at high tide. Levee patrols were driving the island in 15 minute shifts, looking for bubbling and keeping vehicles off. It was quite a site. I'm sure BI, Jersey and several other islands would have flooded if the others upstream had held.
 
quote:
Originally posted by Flutterby

Many of those delta islands are planned as future housing developments, so the levees need to be maintained and improved or the developers told "no". Fat chance of that happening!

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I'm sorry Flutter, but this statement is not correct. There will be no new developments in the Delta Primary Zone. The proposed Old Sugar Mill project in Clarksburg (Yolo County) was shot down by the Delta Protection Commission just days ago for that very reason. Here is a map of the Delta Zones. The Primary Zone (Delta agriculture only) is in buff color.

http://www.delta.ca.gov/atlas/zone.pdf
 
I estimate the sea rising due to global warming to be not at the top of the delta's flooding concerns. Older, less precise data over the last 600 years shows the oceans rising 6 feet in that amount of time. About a week ago in the SF Chronicle was a front page story about the rising sea at the golden gate, it's gone up about 9 inches over the last 150 years. It's a problem the delta will need to deal with, but I believe higher than that is the simple fact of the poor state of the levees in the first place. Islands dropping and rivers and sloughs silting in I'm sure are at least as much a threat as rising oceans from global warming.

I remember a few years back (maybe 1999?) driving along Georgiana Slough near the Oxbow Marina. The water level was extremely high. The levee road had slight elevation changes that you don't immediately notice, but when the river is there to meet it, it was very clear to see. The low parts of the road had maybe a foot high of sandbags, as the levee actually had a few low spots that were lower than the level of the river.
 
Yzer......as usual, you have more up-to-date info then I. But when I looked at the link you provided, I see that the specific area I had in mind when making my comments [but did not specify] is coded as secondary. That is the area from Rio Vista to Isleton to Potato Slu, along Hwy 12. That should be a primary zone, in my opinion, but developers have already purchased the property, so they were rewarded with a secondary zone designation!

westdelta......it was 1997. I'm curious in your comments about SF GG: did the total volume of water increase or did the waterline go up because more mud and silt settled there? With all of the hydrolic mining in the gold country in the 1800s, lots of earth was moved downstream and out the gate. That is what created the potato patch.
 
Flutterby: I might still have that Chronicle in the truck, I'll check it out. It showed a graph over 150 years, showing a steady increase throughout the whole time. I don't think the graph was volume of water, I think it was showing that both the high and low tides were getting higher at that spot. But I don't know if it was taking possible silting of the strait into account, which it might be hard to come up with reliable data for depths there going back more than about 50 years.
 
There should be data up to about 1930 when the GG Bridge was engineered.......
 
quote:
Originally posted by Flutterby

Yzer......as usual, you have more up-to-date info then I. But when I looked at the link you provided, I see that the specific area I had in mind when making my comments [but did not specify] is coded as secondary. That is the area from Rio Vista to Isleton to Potato Slu, along Hwy 12. That should be a primary zone, in my opinion, but developers have already purchased the property, so they were rewarded with a secondary zone designation!

Click to expand...

That secondary zone you are talking about runs from the east end of the Rio Vista bridge and includes everything north of Hwy 12 all the way to Georgianna Slough north to Isleton.

Clarksburg, Courtland, Locke and Walnut Grove are locked into the no-growth zone. Isleton got the secondary zoning. I suspect it's no coincidence that this leaves each county in the central Delta with one money-making piece of the Delta pie. Yolo has West Sacramento, San Joaquin has Stockton, Solano has Rio Vista and Sacramento has Isleton.

It's no coincidence either that Delta Chambers will be locating it's new welcome wagon east of the Rio Vista bridge and north of highway 12.

Like you, I would like to see this zone stay primary and farmland, but there are compromises that had to be reached. At least, the Delta Protection Commission got as much as it could, because uncontrolled growth would have trashed the Delta.

Army Corps of Engineers must consider zoning as it prioritizes its work. They don't do the zoning.

Someday in the not so distant future Isleton and Rio Vista will be two Delta communities clustered together and connected by a bridge. Hwy 12 will probably be a four-lane, unless a modern riverboat ferry system gets developed. That's not a bad idea but not likely, because Hwy 12 is a valuable short cut used by commuters, truckers and local residents.
 
quote:
Originally posted by yzer

I suspect it's no coincidence that this leaves each county in the central Delta with one money-making piece of the Delta pie. Yolo has West Sacramento, San Joaquin has Stockton, Solano has Rio Vista and Sacramento has Isleton.
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That is a very astute observation. Interesting how these decisions are made.
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