Tuesday, January 15, 2013

It's Time For a Serious Study of the West Delta Intake Concept

I admit that I didn't pay much attention the first time I heard Bob Pyke describe the West Delta Intake concept nearly two years ago. 

Then I started talking to local fisherman, boaters and farmers for the DPC Economic Sustainability Plan.  I recall talking to one gent in Lodi who had been fishing the Delta for decades who said, "They should just put the intakes in the Carquinez Straight."  I asked, "Do you know Bob Pyke?"  "Nope."  Over the next few months, I heard some other comments from Delta locals suggesting intakes at the Antioch Bridge, Rio Vista, etc.  "Do you know Bob Pyke?" I asked.  No, they said.  While they claim not to know him, I am pretty convinced Bob stole his idea from some Delta locals while drinking in a local bar.  It involves too much common sense to spring from the mind of a Ph.D.

Seriously, these conversations made me realize that this was a conveyance concept that might get in-Delta support, and I can't recall ever hearing a local say they should just build a little pipe (or a 3,000 cfs tunnel).  West Delta intakes passes the common sense and fairness test of many people who actually live in the estuary.  That's nice I thought, but it isn't a good enough reason to build it.  I still mostly dismissed it as an expensive civil engineers' flight of fancy.

Over the past year, Dr. Pyke has been filling in details to the concept while the BDCP tunnel concept flounders, delivering less water and more cost with each iteration of the BDCP plan.  And the more I learn, the more I think West Delta intakes could be a viable option, and apparantly I am not alone.  At this point, it seems very likely to me that the West Delta concept delivers more benefits at lower cost than the BDCP tunnels.    

In the recent article in the Record, the sub-headline focuses on the potential cost savings, just like most coverage of the fat, seismic-resistant levees we recommended in the Economic Sustainability Plan.  But I think the key to appreciating both the fat levees and West Delta Intakes is to understand that they provide more benefits than the alternatives, rather than focus on the costs.

Of course, this all needs to be studied in detail.  I agree with Larry Ruhstaller in the Record article,
Simply studying the plan can't hurt, Ruhstaller said Friday.
"If there's a fatal flaw, let's find it," he said. "We think there's a lot of fatal flaws" in the governor's plan.
Why should we be looking at this alternative?  Take a quick look at the some of the more significant potential benefits and costs.  It certainly seems promising.  What's the harm in a study?

Potential Benefits of the West Delta Intakes Compared to the Tunnels

1.  More Water Exports.  For years, I have been hearing about the "Big Gulp, Little Sip" approach to the Delta; that we need to take more water in wet years and less in dry years.  That has been a selling point of the tunnels, but it appears that the tunnels aren't able to actually take that big of a gulp.  Bob's design would allow a bigger gulp by having significant storage between the intakes and the aquaducts, and having ten miles of "intakes" along wide channels on Sherman island feeding conveyance tunnels with 15,000 cfs capacity as opposed to 9,000 cfs in the current BDCP plan.  Because the intake location would create water quality issues in dry years, it seems there would be no choice but to take a little sip in dry years. 

Overall, it seems the average level of exports would be higher than the BDCP tunnels.  The failure of the current BDCP to significantly increase water exports in return for a $14 billion investment from water exports is a key reason why BDCP makes no economic sense, especially for farmers.  While the tunnels offer some water quality benefits for exporters, the water supply is more important.  By my rough calculations, average water exports need to get to 6.5 to 7.0 maf before a $14 billion investment in conveyance makes economic sense for water agencies.  We know BDCP can't get to those levels.  The West Delta concept has a shot, and it should be studied.

2.  More Benefits for Fish.  The West Delta "intakes" would be 10 miles of coarse sand and rock levees where water would be pulled in at much lower velocity than the proposed BDCP intakes, which might collectively add up to nearly a mile of screened intakes.  The channels are much larger near Sherman island too, so it intuitively makes sense to me that salmon and other fish would pass by much more easily.  And the design of the plan would put a physical constraint (not a rule that can/will be broken) on dry year water exports, which is said to be critically important to fish.

But I don't know anything about fish, so don't listen to me.  Let's get the biologists to study it.  While DWR has expressed concerns about Delta Smelt in this region, I seem to recall some environmental experts touted by DWR - and high-level Delta Stewardship Council officials saying things like we must accept that we might lose some species in order to improve the overall ecosystem and achive the co-equal goals.  I am not saying that we should let the Smelt go or even that the West Delta concept is harmful to Smelt.  I am saying that concerns about Smelt is not sufficient justification not to study the West Delta concept given that they have continuously studied conveyance concepts that are known to harm endangered species.

3.  Better for in-Delta interests.  There is no arguing this. And yes, they matter.

4.  Better for non-water concerns such as transportation and public safety.  Dr. Pyke's proposal talks about transportation improvements on Sherman Island, but I would make the larger point that his plan would build upon levee upgrades throughout much of the Delta as recommended in the Economic Sustainability Plan.  If you believe that the risk of a major seismic event in the Delta is high enough to demand action, then you must realize that transportation, life loss and other infrastructure and property loss in the event of a Delta quake is a much larger risk than water exports.  Real solutions to seismic risk in the Delta protect all these values, not just water exports, and the BDCP tunnels fail on this criteria.  West Delta intakes aligns the water exporters interests with the rest of the state when it comes to addressing seismic risk.  This is a critical issue that I will write about in the future.  These levee upgrades need to be done regardless of any conveyance solution that may be implemented, but there is a real risk it won't happen if the BDCP tunnel plan goes forward. 

In addition, it offers an advantage over the BDCP tunnels in that it improves all stakeholders relative to the so-called "status quo". That is an attribute with real societal value, and it also has practical value when it comes to navigating lawsuits, politics and getting a conveyance permitted and built. 

Potentially Lower Costs Than the Tunnels

Would the construction costs be lower than the tunnels?  I'm not sure, but it seems unlikely to be significantly higher.

The most obvious saving is that the conveyance tunnels would be less than one-half the length of the BDCP proposal.  That is a large cost saving on tunnels, but the West Delta concept also includes additional costs for new storage.  The reconfiguration of Sherman Island, dredging out the peat, building the 10 miles of permeable sand/rock levees and other improvements will be expensive, but might not be much more than the North Delta intakes and forebay in the BDCP plan, which are also really expensive.  

So what's my preliminary conclusion on the WDIC.  I think there is a significant probability that the concept has higher overall benefits than BDCP tunnels, and it is unlikely to cost more and might have lower costs than BDCP tunnels.  It definitely merits a rigorous study.   

For the details and a better explanation, check out Bob's accessible 13 page description of the concept and why it makes sense here.  He's got a brief addendum floating around to that gives more details on permeable levees too.  I don't have a link to the addendum, but will try to post one later.

Update:  Here is a link to the addendum.


  1. People understand numbers, so it's good to see an economist's support for vetting Dr. Pyke's proposal.

    Though the proposal seems well-grounded in common sense, it remains unclear whether the specifics will hold up to engineering and scientific scrutiny But clearly there many political advantages that the western conveyance idea has.

    Good work as always, Jeff.

  2. Well, there aren't too many numbers above and I don't have enough information to make a judgement.

    We need some independent numbers.