The gates are too short

POST UPDATED 8/25/12 - SEE BELOW

You are reading that right. The gates are too short.

I'm referring to the three outfall canal gate structures that the Corps built in 2006 and 2007. When the gates drop, their tops are 16 feet above the lake. That matches the top of the adjacent protection in Orleans Parish.

However, that does not meet the Corps' own design guidelines, which have been in effect since October 2007. From page 23 of chapter 1 of the Corps' Hurricane and Storm Damage Risk Reduction System Design Guidelines:

"Structural superiority is incorporated in the design elevation for those structures that would be very difficult to rebuild, if damaged, because of disruption in services. Examples are major highway and railroad gates that require detours, pumping station fronting protection that requires reductions to pumping capacity, sector gated structures, etc. These structures are to be constructed to the 2057 levels plus 2 ft. for structural superiority."

And then on page 3 of chapter 5:

"Structural Superiority – All new structures that are difficult to construct due to their nature, such as railroad and highway gates, pump station fronting protection, sector gates, utility crossings, etc., shall have a minimum 2 ft. overbuild."

The Corps is incorporating structural stability into all its major flood protection structures, like the IHNC-Lake Borge surge barrier, the West Closure Complex, and the Bayou Dupre gate in St Bernard Parish. In fact, Karen Durham-Aguilera crowed about it at the November 5, 2009 City Council hearing (at 2:09:09) when describing additional factors on top of the Corps' 100-year design heights:

"We project subsidence out over 50 years, we add numerous factors of safety so that we add more for that. We add more for what we call structural superiority if it's a hardened structure that we would have to rebuild that it would be too hard to add on to."

Most obviously and relvantly, the extra two feet show up in the proposed design criteria for the new permanent pump stations which will replace the current gates and pumps. On pages 9, 10, 15, 21, and 48 of those criteria, the height of the gates at all three future stations is required to be a minimum of 18 feet, or two feet higher than the current gates. Here's the reference on page 15:


On page 48, a full explanation is given, explicitly citing the structural superiority requirement:

"5.5.9 Structural Superiority
Any PPS [Permanent Pump Station] facilities, structures, civil works, or other components that form a structural portion of the storm surge barrier, or that will be located in areas subject to direct storm surge, shall include structural superiority design features as described below. Structural superiority is required to enhance the ability of the structure to survive potential overtopping events. Structural superiority refers to adding structure height to prevent overtopping of structures.

Structural superiority shall be included as follows:
1. Where structural superiority is required, tops of structures shall be a minimum of two (2) feet above the design grade of the adjacent levees/floodwalls. For this project, minimum structural superiority elevation shall be 18.0 feet."

So despite knowing
a) that the future gates will be 18 feet off the water,
b) what the current flooding threat is, and that it requires gates taller than 16 feet, and
c) that the current gates are 16 feet,

the Corps has not done anything to address this increase in risk. That is, they haven't moved to add two feet to the top of the current gates to protect the city in the intervening years before the permanent pump stations are built. Keep in mind the current gates are scheduled to be in service for at least four more hurricane seasons, and all that time the Corps apparently believes having gates that are too short is okay.

The Corps even knows that 18 feet probably isn't enough for the 100 year criteria. Earlier in the document, they call out the 100 year "still water elevation," (i.e. the surge without waves) in the lake as 10.2 feet. Then they call out the lake wave run up on vertical walls (how much above the still water level waves will wash) as 9 feet. Thus, they are expecting a 100 year storm (which roughly corresponds to a category 2 or 3) to have water go over even an 18 foot wall. Imagine what happens on the other side of a 16 foot one.

The scary thing is that when the gates were in the design phase, they were actually going to be two feet shorter than they are now. Take a look at this early design sketch of the 17th Street closure structure (likely from late 2005), taken from a 2007 presentation given by the design engineers on the closure strucutres, URS and Linfield, Hunter, and Junius:

That drawing shows the gates as topping out at only 14 feet. Scary.

Also, this is not simply an academic difference. There is a reason more height is required at structures like these gates. In this case, they need to protect the actual guts that make the gates work. The extra height would also help protect the equipment that locks the gates in place during a storm. Two extra feet would go a long way toward that protection.

But even without that extra two feet, there are robust systems in place to make sure the gates are protecting the city properly during a storm, right? I mean, surely those locking mechanisms are always operated correctly, right? It's not like the Corps would simply leave the gates unsecured and violate their own procedures, would they?

Um, yes, they would. More on that coming up...

Update - 8/25/12

The Corps is actually planning on following this same strategy - i.e. violating their own guidelines by installing gates that are too short - with the permanent pump stations, as reported in the Times Picayune on May 14, 2012. At the very end of an article about the restarting of the bid process on the permanent stations after the first bids were thrown out as a result of successful protests, there's this mention of changes in the bid specifications:

"Three separate investigations by corps officials found no impermissible conflict of interest created by CBY's hiring of Richmond Kendrick, the former corps official. But the GAO found the other complaints were valid, and in October 2011, the corps decided to request the five finalists to respond to a proposal changed to reflect the GAO's recommendations. The changes included language that now says only that proposals over $700 million would not be accepted.


Also removed was a request to minimize impact of construction on the Coconut Beach volleyball complex, which had been located within the footprint of the proposed 17th Street Canal station. The complex is moving to Kenner's Laketown area.

Several other design changes, including reducing the required height of surge protection to 16 feet above sea level, from 18 feet, were included.

The corps' decision to reopen the bid process prompted CBY to file suit."

There's only one reason to do this: cost.

Poundfoolish, Part 1

Update - 12-9-09
Video of the December 9, 2009 City Council committee meeting is available here

[Update - 12-8-09
The Corps' appearance has been moved to Wednesday, December 9th, at 2 PM CST as part of a joint Recovery/Public Works City Council Committee meeting. The Corps is the only item on the agenda here. The meeting will be streamed on the City Council's website here.]

[NOTE: The Corps will be appearing before the New Orleans City Council on December 7 to speak about their $90 million work on the outfall canal walls, which is supposedly not actual modification. They will also be asked about the over half billion dollar property tax increase Option 1 drops on New Orleans over the next 50 years.

The press release is here. The agenda is here. Live video will be available here on the day of the meeting.]

At the November 19, 2009 meeting in which Colonel Sinkler revealed the Corps is planning on spending $90 million modifying the outfall canal walls and levees (despite their staunch adherence to the "we're not authorized to modify the canals" talking point), the Corps released part of the Phase One Request for Proposals for the permanent pump stations. It is a scope of work, with design criteria. The Corps' consultants, Black & Veatch, refer to it as a "Statement of Work." I'm going to call it a Scope of Work, which is the more common term.

Releasing this sort of thing for comment is not unusual, despite how the Corps might portray it. The difference is allowing the public to see it. Usually it is public agencies and contractors that get a sneak peek before it is officially issued. This particular document has been floating around behind the scenes since about March of this year. Note that the revisions (in the lower corner of each page) are already at "K," meaning this is at least the 11th version of this document.

As with many documents the Corps releases, parts are missing. At least three appendices ("A" through "C") are not included. Also, this document represents but a small sliver of the overall RFP. Among the things missing are drawings, other technical specifications and all the commercial terms, which together would likely dwarf the 82 pages released to the public by a factor of five.

Overall, I would call the document "choppy." You have to look in multiple places for some things, and there's a lot of vagueness where there should be certainty.

I thought I would go through the features I reviewed in the earlier "Pennywise" posts (Parts 1, 2, 3, and 4) and see how the Corps/Black & Veatch is specifying them. I've rejiggered the list a little, but the links still point to the correct posts.

1) Formed Suction Intake
2) Includes Floodwall/Levee Upgrades
3) Includes Gated Bypass
4) Canal Transitions
5) Deepened Sill
6) All Electric Pumps
7) Pump Station Sized for Future Pump Capacity
8) Pump Capacity Sized for Future Pump Capacity
9) Fuel Storage and Generator Sized for Future Capacity
10) Includes Siphon Recovery
11) Includes Breakwater
12) Stilling Basin at Discharge
13) Removal of ICS Facilities

Formed Suction Intakes, Spare Pumping Capacity, and Taxes

The area around the pump inlets is the best example of how Corps cost cutting gets out of control, and actually harms projects.

I wrote quite a bit about pump inlets in Pennywise, Part 2. To review, the Corps does not wish to install Formed Suction Inlets (FSI's) on the inlets of the Option 1 pumps, even though they would save costs in the future and make eminent sense to put in now. They wish to simply leave the pump inlets bare, similar to a straw in a drink. Formed Suction Inlets will be required in Option 2, when the canals are deepened. That is because they are the only inlet design (according to the Corps) that can handle the shallower depths of water that will come with the deeper Option 2 canals.

The Corps installed FSI's on the direct drives at 17th Street and London Avenue in 2007. They provided a graphic in the February 21, 2007 Task Force Hope Update:


The newly released Scope of Work codifies the Corps' twisted reasoning, but provides an even more dangerous dimension to the problem.

Here's the relevant verbiage on pump inlets (ironically found in the section of the Scope dealing with adaptable features):

"PPS [Permanent Pumping Station] pumping station inlet, intake area, and gate structure [shall be] designed to accommodate Possible Future Condition pumps without structural modifications to the pumping station. Note that addition of formed suction intake (FSI) structures is not considered a structural modification if they can be added without demolition of the initial pumping station structure and if they can be added without requiring a pumping station shutdown. Shut down of an individual pump during modifications is permitted."

Taken in isolation, this statement might seem reasonable. But one needs to also consider that the Corps does not plan on including any spare pumping capacity beyond the bare minimum required to match the existing pump stations' flowrates (based on current flows at all three canals and future S&WB expansions at 17th Street and London Avenue). So without any spare pumping capacity, how exactly would a future pump-by-pump shutdown impact the ability of the Sewerage & Water Board to drain water from the city during a storm event? It would harm it, severely.

This is horrible, cut-costs-to-the-bone engineering that USACE seems to specialize in. It's bad enough they are:

- cheaping out on a component they are already designing for elsewhere (another paragraph on the same page as the passage above calls for the inlet channel to allow water flow velocities suitable for FSI's),
- moving those FSI fabrication and installation costs to Option 2 to make their Option 1 budget look better,

But to top it all off, they are hamstringing the future operations of the lakefront stations - and adding risk to the citizens of the city - while Option 2 is under construction.

And in the final analysis, they are likely putting in a technically inferior pump inlet which causes more vortices and will shorten the life of the pumps in the long term.

Spare Capacity - not so much
And just to go back to the point about no spare capacity, because I don't want to bury a lede. The Corps has always, public statements notwithstanding, intended to do the bare minimum on these stations. Their constant delays, the lack of attention, and the raiding of funds all point to how low a priority the pump stations are on their scale. But to now have their skimping then place the citizens at risk in the future is inexcusable.

The Corps plans (apparently) on installing pumps with peak flowrates of:

17th Street: 12,500 cubic feet per second (cfs)
Orleans Avenue: 2700 cfs
London Avenue: 9000 cfs

The 17th Street flowrate is based on a current flow of 10,500 cfs and a long-planned 2000 cfs expansion by the Sewerage & Water Board. The London Avenue flowrate is based on a current flow of 8000 cfs and a future S&WB expansion of 1000 cfs. So while there might be spare pumps at 17th and London initially, when the S&WB goes to expand their stations on those canals, the spare capacity at the lakefront stations will disappear, because of decisions being made now.

The flowrate at Orleans is based on the current flow. Oddly, the Corps doesn't seem to be considering future expansions at Orleans, even though the Sewerage & Water Board is. So any capacity increase along Orleans Avenue will be completely foreclosed by the Corps' plans on that canal.

It is foolhardy not to design in spare pumps, but that is what the Corps is doing.

Taxes
And one last point: now that we finally have in print exactly what the design flows are for the new stations, we can calculate the exact amount of extra property tax burden the City of New Orleans will incur. That's because the Corps will not be running these new stations, the Sewerage & Water Board will. And the Sewerage & Water Board gets its revenue for drainage operations from property tax millages.

The going rate for annual Operations and Maintenance of the S&WB drainage pumps is $500,000 per 1000 cfs of flow. The total proposed peak flow of all three lakefront stations is 24,200 cfs.

Thus the annual additional tax burden on New Orleans's propertyholders will be $12.1 million. Spread out over the theoretical 50 year lifespan of the stations, that is $605 million.

Along with so many other things, that is a true cost of Option 1 when compared to Option 2. That cost would not exist with Option 2, because Option 2 replaces the existing pumping stations, rather than simply duplicating them out at the lakefront.

Heads up

[Update - 12-8-09
The Corps' appearance has been moved to Wednesday, December 9th, at 2 PM CST as part of a joint Recovery/Public Works City Council Committee meeting. The Corps is the only item on the agenda here. The meeting will be streamed on the City Council's website here.]

The Corps wil be appearing before the New Orleans City Council on December 7 to speak about their $90 million work on the outfall canal walls, which is supposedly not actual modification. They will also be asked about the $500 million property tax increase Option 1 drops on New Orleans over the next 50 years.

Agenda is here. Live video will be available here on the day of the meeting.

Update 12-8-09
Media coverage from this brief appearance can be found at WWL-TV's site here, and Fox 8's site here (Fox 8 video here). The entire raw video of the appearance is at the City Council's website here.