Mt Whitney Webcam
Mt Williamson Webcam
Feature Topics
Who's Online
0 registered (), 23 Guests and 36 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
3702 Members
10 Forums
5555 Topics
50876 Posts

Max Online: 382 @ 11/07/12 05:45 AM
Page 1 of 4 1 2 3 4 >
Topic Options
#33773 - 10/13/13 09:29 PM Dr. Ken Murray on LA and water
AlanK Offline


Registered: 09/22/09
Posts: 583
Loc: Glendale, CA

Top
#33805 - 10/16/13 12:59 PM Re: Dr. Ken Murray on LA and water [Re: AlanK]
Harvey Lankford Offline


Registered: 11/10/09
Posts: 1019
Loc: Richmond, Virginia
hope some of the methods in Ken's article result in water staying in the Eastern Sierra... but that may be a pipe dream

Top
#33809 - 10/17/13 07:18 AM Re: Dr. Ken Murray on LA and water [Re: Harvey Lankford]
SierraNevada Offline


Registered: 09/05/11
Posts: 1139
Loc: NorCal
Good write up. These are all good ideas, but unfortunately, water independence is a pipe dream for southern Cal. There's a lot they need to be doing as described by Ken, but deserts don't support this level of population density without bringing in water.

Recycling water is a PR problem but it's moving forward in San Diego after years of being called "toilet to tap." It will help, but recycling half their water supply seems very optimistic.

Ken wrote, "Rainwater capture is also promising. In just one large rainstorm, 10 billion gallons of runoff, one-twentieth of our yearly need, end up in the Pacific Ocean. The technology to capture large quantities is not quite developed, but people are working on it.

What is this referring to? The "technology" of capturing rainwater is called a "dam". New dams built over the last 25 yrs have helped South Cal weather the fluctuations in imported supply and prepared them for an earthquake disruption.

Top
#33814 - 10/17/13 01:22 PM Re: Dr. Ken Murray on LA and water [Re: SierraNevada]
Harvey Lankford Offline


Registered: 11/10/09
Posts: 1019
Loc: Richmond, Virginia

here in VA, one guy proposed piping Hampton Roads Sanitation District treated sewage/storm water "clean as tap water" to industrial users like paper mills, otherwise they will suck all the well water another 100 ft lower, or until it is all gone.

This usage sounds easier to sell than drinking it.

Top
#33836 - 10/20/13 08:55 AM Re: Dr. Ken Murray on LA and water [Re: Harvey Lankford]
SierraNevada Offline


Registered: 09/05/11
Posts: 1139
Loc: NorCal
There's a lot of recycled water being applied to golf courses in SoCal and I think in Arizona as well. This can require dedicated new pipelines if the water doesn't meet drinking water standards, which are getting more strict all the time. The new pipelines can add a lot of cost. If they treat it to drinking water quality, then they can mix it into the established distribution system without new pipes.

Back to Ken's main point, there's only so much rain that falls in SoCal, and it gets contaminated as it travels the stormwater system, so the numbers don't add up for full "water independence" in today's society. Eventually, conservation efforts hit a point of diminishing returns (we still have a lot we can do to conserve) and population growth becomes the critical factor. No harm shooting for this as a goal and getting as close to it as possible, but don't lose credibility along the way. SoCal will need to import and store large quantities of water for the foreseeable future. They're getting smarter about it all the time.

Top
#33855 - 10/21/13 03:33 PM Re: Dr. Ken Murray on LA and water [Re: AlanK]
Ken Offline


Registered: 10/29/09
Posts: 742
Loc: Los Angeles
Alan, thanks for the post.

This has been getting a lot of attention, particularly since it was reprinted on the Times Mag site.

I serve in a volunteer capacity on a couple of committees devoted to water for LA, and as I have gained expertise in the understanding of institutional issues, it's been an education. There is currently proposed a recycled water project for the San Fernando Valley. Very straight-forward, only involves advanced treatment of already highly purified water, then spreading to percolate into the ground. Already own the land and easements, already have the full technology and expertise within LADWP. Assuming no delays, not a drop of water will be produced before 2022. It takes astonishing time to build infrastructure.

Rainwater harvesting is an interesting problem. LA is in a unique situation, unlike many cities whose runoff simply goes to a downstream user. Harvesting for them means a shortage for someone else. Not so, LA....it runs into the ocean.

There are two major river systems running through the LA basin: LA River, and the San Gabriel River. Nearly 0% of the LA River stormwater is captured, nearly every drop of the San Gabriel River stormwater is captured.

The Center and West Coast basins, to the south and east of Los Angeles have already planned such a program out for independence from distant sources. It is supported by the population, strongly. It is being build now.

http://www.wrd.org/news/water-articles.php?url_nws=water-independence-network

In terms of capturing storm water, the traditional methods are quite problematic in the LA basin. Only 20% of the water is from "rural" watersheds, where traditional approaches such as dams might work. Problem is, there are no dam sites in our earthquake prone region in the watershed. So that requires different thinking about how to capture the water.

I've been particularly interested in a technology called "sand dams", which are a transformational approach used widely in Africa and Asia.

http://en.wikipedia.org/wiki/Sand_dam

About 80% comes from impermeable surfaces, that direct the water into the cement lined LA River.

So we have to look at innovative ways of managing storm water. One way has been the development of "permeable" street, driveway, and sidewalk surfaces, and the development of codes that require their use. Another way has been the development of the "green street" concept, possibly best developed by Portland. This short video shows what is possible, in capturing most water at the street level:

http://media.ci.portland.or.us/greenstreets/greenstreets.html

It is well to remember that 100 years ago, more people died from drowning in floods than anything else in LA. But the pendulum swung too far, and everything was created to get the water to the ocean.

Top
#33856 - 10/21/13 07:26 PM Re: Dr. Ken Murray on LA and water [Re: Ken]
Bee Offline


Registered: 09/22/09
Posts: 1261
Loc: Northern California
Excellent collection on the subject of water conservation.

I am intrigued by the drowning deaths in LA -- is it because the area used to have flash floods/monsoon conditions much like Az?
_________________________
The body betrays and the weather conspires, hopefully, not on the same day.

Top
#33858 - 10/21/13 08:52 PM Re: Dr. Ken Murray on LA and water [Re: Bee]
Steve C Offline


Registered: 09/22/09
Posts: 7680
Loc: Fresno, CA
I am amazed at the sand dam technique.

Top
#33862 - 10/21/13 11:21 PM Re: Dr. Ken Murray on LA and water [Re: Ken]
SierraNevada Offline


Registered: 09/05/11
Posts: 1139
Loc: NorCal
Originally Posted By: Ken
Assuming no delays, not a drop of water will be produced before 2022. It takes astonishing time to build infrastructure.

Nice groundwater recharge project. What is the hold up on this one? Is funding the issue? The most common delay is environmental permitting - years for an EIR and related permits for anything major, and then a few lawsuits on top of that usually.

Originally Posted By: Ken

The Center and West Coast basins, to the south and east of Los Angeles have already planned such a program out for independence from distant sources. It is supported by the population, strongly. It is being build now.

http://www.wrd.org/news/water-articles.php?url_nws=water-independence-network

Let's be clear here, it's another great project, but this is not water independence. The project you linked to is trying to stop importing water for the purpose of recharging the groundwater. A lot of that goes to stop saltwater intrusion into the aquifer. They're importing 11,500 acre-feet, which is a drop in the bucket for that population.

I don't want to rain on your parade, these are all great projects, but let's get the numbers straight. This graphic says it all - look at the south coast. The unimpaired water availability is much lower than the use. If they captured all the rainfall, the urban use would still have to drop in about half from what it is now. Those are two huge goals that are worth struggling for, but not likely to ever happen.

Top
#33863 - 10/21/13 11:52 PM Re: Dr. Ken Murray on LA and water [Re: Bee]
Ken Offline


Registered: 10/29/09
Posts: 742
Loc: Los Angeles
Originally Posted By: Bee
Excellent collection on the subject of water conservation.

I am intrigued by the drowning deaths in LA -- is it because the area used to have flash floods/monsoon conditions much like Az?


Yes.

The numbers are quite impressive for what can be done.

Total water use for the City of LA is about 200 billion gal/year.

The stormwater can amount to 10 Bill Gallons/rainstorm, with about 10/year.

Quote:
"This isn't wastewater until we waste it," said Noah Garrison, an attorney with the Natural Resources Defense Council who co-wrote a 2009 paper on capturing and reusing storm water.

The report concluded that the region could increase local supplies by an amount equal to more than half of Los Angeles' annual water demand by incorporating relatively simple water-harvesting techniques in new construction and redevelopments


There is half of the replacement

I mentioned leaky pipes.

There are innovations in the pipes:

http://www.dailynews.com/general-news/20130221/earthquake-resistant-pipes-may-bring-leak-free-la

If we are like Singapore, we may loose as much as 40% of the imported water to leaks. That means that only 60% is reaching our homes. If we cut the loss from 40% to about 10%, as they did in Singapore, that means that we would get 30% more. Since the current total is 60% (not 100%, because 40% is lost), That would effectively make available 1/2 of the current total.

That's the other half. That replaces all of it.

Of course, nothing is 100% efficient.

But that doesn't even include any progress in conservation nor recycling, both of which can produce significant percentage savings.

But lets say we can't get any better than 75% off of distant sources.....I would not consider that a failure, but a huge success. The technology exists right now.


Edited by Ken (10/22/13 12:27 AM)

Top
#33864 - 10/21/13 11:55 PM Re: Dr. Ken Murray on LA and water [Re: Steve C]
Ken Offline


Registered: 10/29/09
Posts: 742
Loc: Los Angeles
Originally Posted By: Steve C
I am amazed at the sand dam technique.


quite to my astonishment, none of the water engineers I've talked to have ever heard of it, although it's use is widespread in the third world.

I would find it ironic if the advanced first world would end up borrowing a technique pioneered in the third world

Top
#33867 - 10/22/13 11:02 AM Re: Dr. Ken Murray on LA and water [Re: Ken]
Ken Offline


Registered: 10/29/09
Posts: 742
Loc: Los Angeles
A study conducted by NRDC and the University of
California, Santa Barbara, A Clear Blue Future, found that
implementing green infrastructure practices that emphasize
on-site infiltration or capture and reuse had the potential
to increase local water supplies by up to 405,000 acre-feet
per year by 2030 at new and redeveloped residential and
commercial properties in Southern California and the San
Francisco Bay area. This represents roughly two-thirds of the
volume of water used by the entire city of Los Angeles each
year.


These water savings translate into electricity savings
of up to 1,225,500 megawatt-hours—which would decrease
the release of carbon dioxide (CO2
) into the atmostphere
by as much as 535,500 metric tons per year—because more
plentiful local water reduces the need for energy-intensive
imported water.
And, perhaps most importantly, these
benefits would increase every year
.13

This analysis led to the inclusion of green infrastructure
as a strategy in California’s “Land Use Planning and
Management,” signifying the state’s recognition of green
infrastructure’s value in water supply planning in the State
of California.14 Green infrastructure was also included as
a strategy in California’s Global Warming Solutions Act
of 2006 (AB 32), in recognition of its ability to to reduce
energy demands associated with the transport of water.15
Similar benefits, at least in terms of water supply quantity,
are available throughout the country. An NRDC report on
rainwater capture released at the same time as this report
demonstrates that the volume of rain falling on rooftops
in eight different cities, if captured in its entirety, would
be enough to meet the annual water needs of 21 percent
to 75 percent of each city’s population.
Even under more
conservative assumptions, the study demonstrated that each
of the cities modeled could capture hundreds of millions
to billions of gallons of rainwater each year—amounts
equivalent to the total annual water use of tens of thousands
to hundreds of thousands of residents.16


http://www.nrdc.org/water/pollution/rooftopsii/files/rooftopstoriversII.pdf

Top
#33877 - 10/23/13 12:02 AM Re: Dr. Ken Murray on LA and water [Re: Ken]
SierraNevada Offline


Registered: 09/05/11
Posts: 1139
Loc: NorCal
Originally Posted By: Ken
Originally Posted By: Steve C
I am amazed at the sand dam technique.


quite to my astonishment, none of the water engineers I've talked to have ever heard of it, although it's use is widespread in the third world.

I would find it ironic if the advanced first world would end up borrowing a technique pioneered in the third world

A "sand dam" is just a notched weir in a dry river channel that eventually fills with sediment. As long as the ground is relatively impermeable, the weir will store water with or without the sand, more without it actually.

There are good reasons why they only use this desperate method in 3rd world countries. Putting weirs in the LA river (a concrete channel now) or any other flood control channel or dry riverbed would invite disaster by impeding flood flows.

The beaches of So Cal are starved for sand transported from upstream, so this would have unintended environmental consequences - the permit would involve creating a new desert somewhere or some other costly crazy mitigation. Also, the sand would be contaminated with the usual urban stormwater pollution - oil and gas, fertilizer, pesticides, etc. And lastly, how would they film those car chases in the LA aqueduct with all that sand blocking things? smirk

Lots of other ideas Ken posted are great even if the benefits are exaggerated, in my professional opinion. Rain catchments off roofs are widely used in Hawaii and could provide some additional water in SoCal. Groundwater recharge "conjuctive use" is really ramping up but legally dicey (no clear water rights law on how much you can pump out). BTW, leaky pipes are doing just that - recharging the groundwater, so not all that water dripping is "lost", which again means the benefits of patching leaks are overstated. But sediment laden weirs in flood channels? Ain't going happen here.

One of the big problems with most of these ideas is that water comes in big gulps over a few months and then it's dry for 8 months. Storage is the key, and the ground can only absorb so much when it's either paved or saturated. And the biggest problem goes back to that chart I linked to. You'd have to capture every single drop of rain and then cut all urban use in SoCal in half to achieve energy "independence" from outside sources. Do you really see that happening? Keep moving in that direction by all affordable means, but be realistic about it.

Top
#33887 - 10/24/13 11:07 AM Re: Dr. Ken Murray on LA and water [Re: SierraNevada]
Ken Offline


Registered: 10/29/09
Posts: 742
Loc: Los Angeles
The only thing is that other groups in the LA basin have done EXACTLY that:

http://www.sgvtribune.com/environment-an...heastern-county

Quote:
residents of 43 cities in southern Los Angeles County.

Four million residents from cities within the Water Replenishment District, from Montebello to Long Beach and Torrance to Cerritos, will have a local, reliable water source to boost well-head supplies. Soon, the WRD will no longer have to buy any water from the Colorado River or the Sacramento-San Joaquin River Delta in Northern California,


How did they do it? Stormwater capture, water recycling, conservation.

what I find frustrating is engineering types that inhabit water agencies, and elsewhere, that out-of-hand reject innovation and advancement. They are the types that can provide absolute scientific proof, with many references, that bees cannot fly.

Whereas anyone with eyes in their heads knows that she can. smile

South LA basin is doing it right now, and expect to be off distant water in 5 years. Cannot northern LA basin do the same?

http://www.wrd.org/news/water-articles.php?url_nws=water-independence-network

Top
#33891 - 10/24/13 06:12 PM Re: Dr. Ken Murray on LA and water [Re: Ken]
SierraNevada Offline


Registered: 09/05/11
Posts: 1139
Loc: NorCal
Originally Posted By: Ken
The only thing is that other groups in the LA basin have done EXACTLY that:

http://www.sgvtribune.com/environment-an...heastern-county

Quote:
residents of 43 cities in southern Los Angeles County.

Four million residents from cities within the Water Replenishment District, from Montebello to Long Beach and Torrance to Cerritos, will have a local, reliable water source to boost well-head supplies. Soon, the WRD will no longer have to buy any water from the Colorado River or the Sacramento-San Joaquin River Delta in Northern California,


How did they do it? Stormwater capture, water recycling, conservation.

what I find frustrating is engineering types that inhabit water agencies, and elsewhere, that out-of-hand reject innovation and advancement. They are the types that can provide absolute scientific proof, with many references, that bees cannot fly.

Whereas anyone with eyes in their heads knows that she can. smile

South LA basin is doing it right now, and expect to be off distant water in 5 years. Cannot northern LA basin do the same?

http://www.wrd.org/news/water-articles.php?url_nws=water-independence-network

Am I detecting an attitude about engineers, Ken? The very ones who are solving these problems and making this happen? The vast majority of us want to do these kinds of projects, but let's get the facts straight.

It's not that these districts are not importing water. They are just not going to be importing water TO RECHARGE GROUNDWATER. They still import water for direct use. So they are NOT "water independent." Let me say it again, this groundwater recharge FACILITY will not need to import water to percolate into the groundwater, but that's just a drop in the bucket compared to what the district actually uses.

Here's the link again so everyone can see that the total unimpaired runoff for the entire South Coast region of California is 1/2 of the urban water use. That means EVERY DROP of stormwater runoff would have to be captured AND urban water users need to cut their use in half. That's the big picture number that explains how difficult it would be to truly achieve "water independence."

Ken, we're on the same page about moving in this direction, as I've written above, but I think it's counterproductive to misrepresent the true picture.

How would you feel if I started making pie in the sky statements about completely eliminating heart disease and cancer, insult you and all other doctors, but the solution I'm proposing requires doctors. And yes, you do need engineers to make these things happen. And most all of them, especially the younger ones are 110% onboard with making the world a better place.

Top
#33897 - 10/24/13 09:14 PM Re: Dr. Ken Murray on LA and water [Re: SierraNevada]
Ken Offline


Registered: 10/29/09
Posts: 742
Loc: Los Angeles
whatever........


Edited by Ken (10/25/13 07:56 AM)

Top
#33899 - 10/24/13 10:37 PM Re: Dr. Ken Murray on LA and water [Re: Ken]
Bee Offline


Registered: 09/22/09
Posts: 1261
Loc: Northern California
Originally Posted By: Ken
They are the types that can provide absolute scientific proof, with many references, that bees cannot fly.

Whereas anyone with eyes in their heads knows that she can. smile



Yup! Compliments of a Cessna 152
_________________________
The body betrays and the weather conspires, hopefully, not on the same day.

Top
#33901 - 10/25/13 04:56 PM Re: Dr. Ken Murray on LA and water [Re: Bee]
SierraNevada Offline


Registered: 09/05/11
Posts: 1139
Loc: NorCal
Originally Posted By: Bee
Originally Posted By: Ken
They are the types that can provide absolute scientific proof, with many references, that bees cannot fly.

Whereas anyone with eyes in their heads knows that she can. smile



Yup! Compliments of a Cessna 152

You soar, Bee!

Ken, we agree on 95% of this. Maybe I was a little harsh on the sand dam idea, and I'm just trying to set the record straight on the scope of the challenge to achieve water independence in So Cal. Other than that, we're on the same page with water recycling, capturing stormwater, groundwater recharge, and we didn't even touch on desalination. There's a lot of green stuff that can be done to reduce importing water to So Cal. Let's just keep it in proper perspective.

Top
#33957 - 11/01/13 05:25 AM Re: Dr. Ken Murray on LA and water [Re: SierraNevada]
saltydog Offline


Registered: 02/03/11
Posts: 1563
Loc: Valley Ford CA!!!!
Originally Posted By: SierraNevada
These are all good ideas, but . . . deserts don't support this level of population density without bringing in water.


LA is not in a desert climate. Its not even semi-arid. At just under 15 inches per year of precip, and rain on about 10 percent of days annually, its classified as mediterranean/subtropical.

Regardless of the climate designation, there's a LOT more they can be doing with that 15 inches. The volume of storm runoff, for example, that ends up in the sanitary sewer system is ludicrous. Or at least was years ago when I was studying the problem. I don;t think any major infrastructure upgrades have been made in this regard. Would like to hear that I am wrong about this.
_________________________
Wherever you go, there you are.
SPOTMe!

Top
#33959 - 11/01/13 07:40 AM Re: Dr. Ken Murray on LA and water [Re: saltydog]
Bob West Offline


Registered: 11/13/09
Posts: 828
Loc: Bishop, CA, USA
Yes,LA climate is indeed mild. By about the year 1900 LA, population about 15,000, was beginning to outgrow it's water supply. The main source of LA water was probably from wells. The annual rain wasn't and isn't enough to support a huge population.

In order to facilitate further economic growth water had to be obtained from somewhere. So, why not the Eastern Sierra, where just a few farmers lived? It certainly made sense at the time, especially to land developers...

LA seems to be loath to do anything to obtain water from the ocean, via de-salinization, because it would cost $$$.

It's going to be really interesting to see what happens if the Sierra has to endure another drought winter and the water from the Eastern Sierra goes down to a trickle. Would LA then do what they should do regarding conservation?

Top
Page 1 of 4 1 2 3 4 >