0.02" rain; 1.38" total

10 Dec 2015 0.02"

It came down heavily for an short time and then just sort of fizzled.  I went out and watered the garden.  More rain is on the way, they tell me.


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Surge tanks vs. rain barrels III - storm intensity

In order to answer questions that I have about how large a surge tank is needed to accommodate a certain number of local storms, we need to know about rainfall intensity.  Intensity tells us how much rain we get in a unit of time.

Intensity has a simple answer when considering the duration of a storm as your time interval.  If a storm lasts T hours and it drops 1" of rain, then 1"/ T is the average rate of rainfall.  However, real storms of consequence don't behave like that.  Typically they start out slowly, have a peak rate of rainfall, and then taper off.  From what I've been able to tell, there are two main ways to estimate storm intensity: Using a model hyetograph or using Intensity Duration Frequency (IDF) graphs.

Skunks and possums, living together!

And under my house, too.

The current plan is to wake up at 3AM (there's a +1:12 error in the time stamp on the photos), block the opening with a screen, and then monitor through the screen with the camera trap to see if I've trapped any inside.  If so, let them out the following night.  A one-way door would work better if I can make or buy one.

There's a crawl space vent that is broken and I've blocked it with bricks.  Little good that does.

Surge tanks vs. rain barrels II

In this post I'm trying to estimate the usefulness of a rain barrel operated as surge tank. 

The valve is open all the time when a rain barrel is used as a surge tank.

This is a bit stream-of-consciousness, and engineering-estimate-like so just skip it if that bothers you.  It could very well be wrong too.  I'm not paid in anything other than pride for this writing gig, so fact cross-checking sometimes gets short shrift.  A little Googling provided the information used herein, and I'm sure you can find similar numbers for your area if you care to.

The first question I asked was how big must a surge tank be to capture rainfall effectively in a downpour?

Surge tanks vs. rain barrels I

 I received a few electronic solicitations to get a free rain barrel from my local water district which I promptly ignored.  As I've noted before, they aren't a particularly good investment for southern California.

However, there are a couple specific exceptions to normal situations in which a rain barrel might be a good use of resources in our climate.  One of those is when it's used as a surge tank.  Surge tanks might sound complicated, but the concept of operations for a rain barrel used as a surge tank is not that different than a rain barrel used as a reservoir.

You can have good policy or you can have good customer service

I live in a community that was given a 36% water use reduction target by the state.  Since I've always been careful with my water I thought that I would get credit for good behavior.  Not so, and poor policy is to blame.  So far as I can tell, my water allocation is determined by simple-minded application of the rule: Cut water usage from the 2013 average by 36%, but don't let the allocation drop below 6 hcf per month for any household.

Of course this benefits people who wasted water historically and penalizes those who conserved.  I was one who conserved, and so my water allocation was set at the floor of 6 hcf per month.  I've added a third person to my household, am now housing a teen, and water use is consequently up. Naturally, I petitioned to have a larger allocation.  I got it: Now I have 7 hcf per month, which adds up to about 57 gallons per person per day.  We would have to be reasonably eagled-eyed conservationists to hit that number, which is possible, but what about the fairness issue?  It doesn't take a super genius to intuit that most people aren't being held to similarly low requirements.  If we're all suffering together, then solidarity, brothers and sisters!  But if you are holding me to a tougher standard then f*** off, I'll sue.

A little Googling let me determine that the average usage in my zip code in the middle of last year was 24 hcf (bill insert in 6/2014).  Applying the state-mandated 36% reduction target to the average usage is 15 hcf, more than twice my increased allocation.  This is consistent with a neighbor's report (they are newly arrived in the neighborhood) that their allocation is 14 hcf.

Finally, I received a letter containing this graphic in my mail:

In case you are curious, the entire first page, minus my address information, is shown below in a clickable image.

So I'm using about half the amount of similar homes and I'm being chastised instead of lauded?  Really, I'd like to turn on a hose into the street just to protest.  The curse words flew but after I calmed down I called California Water Service where the nicest customer service person defused me.  She placed re-application for an additional allocation increase into review by management because that's what happens when you've been give the generous upper of 1 hcf already.  Apparently the backlog of management review cases is so large that it will take us into 2016, at which point something will happen.

The something they are probably hoping for is that El Nino will bring sufficient rain that our reductions will not be extended by Governor Brown (they are scheduled to end in February).  The something that I am afraid will happen is that I'll continue to be held to a higher standard than my neighbors and I'll have to participate in a class action lawsuit to change an obviously flawed policy.

0.23"; rain; 1.36" season total

We had a storm through last week which got the cold and wet season under way.  Earlier rain in September and October totaled close to an inch (as well as trace rainfall that I didn't track) which brings us to 1.36" so far at my house.  This isn't such an auspicious start to El Nino, but February is traditionally our wettest month, so we are by no means through with winter yet.

27 Nov 0.20"
25 Nov 0.03"


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0.63" of rain; season total 9.92"

19 Jul 0.43"
20 Jul 0.20"

There's probably some more rain in the near future, but I thought I would note that over a half inch of rain fell locally.  0.38" fell in July of 2007, which is the next highest recent L.A. area rainfall total for the month.  Blame is placed on / credit is given to El Nino for the recent storm.  July of 2007 looks like it was the opposite of El Nino, La Nina, where ocean temperatures are cooler than average.

Earlier I wrote: This is a rainfall total that is exceeded in recent decades only by 1983 (1.25" fell in the L.A. area in August) and 1977 ( 2.47")!  Mean rainfall in the L.A. area in August is 0.07", but most years bring no measurable rain.  Oops.  Those are August figures.

Someone's been eating my Cercis

I was admiring the fog on my Cercis occidentalis



When I noticed some leaf damage and a critter.


Who's been eating my Cercis?



Have some more there's plenty to go around.

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Possum, raccoon, skunk, house cat

I suspect that the raccoons are to blame for the immense piles of scat that have accumulated on top of my patch of Erigeron glaucus (Seaside daisy).  I set the trap in a likely area (not the toilet area, that seemed indelicate) to see who was visiting my yard.

Palo Verde tree

This is a Palo Verde tree in Phoenix, Arizona (Parkinsonia or Cercidium species). In that area these trees are planted all over and appear to reseed frequently. This photo was taken on Memorial Day weekend in Phoenix and it was typical of the trees we saw there - just beautiful. I see them planted more and more in my part of California, but the blooms never look quite like they did in Phoenix. Maybe I just haven't seen them at the right time of year, the weather isn't quite right, or the commonly used California garden selection doesn't have the prolific blooms of the (presumably) wilder Phoenix variety. That can happen - there are three Parkinsonia species and a grower may choose to produce a hybrid or garden selection en masse from cuttings or other method that produces clonal invariants. Bloom seems delayed here by a month or more compared to Phoenix.

Though I live in Palos Verdes, the "green sticks" where my hill gets its name are not the green sticks of the Palo Verde tree branches*: Parkinsonia is is only endemic to the southeastern desert part of the state. Nonetheless, native plant enthusiasts in my area sometimes use Palo Verde as part of their gardens and it looks good - beautiful blooms and striking branch structure.

 There's a Desert Museum selection that was once popular - I think it still is.

In the late 1970's Mark Dimmitt with the Arizona Sonora Desert Museum (ASDM) began noticing Blue Palo Verdes that exhibited characteristics suggesting they were hybrids of other Palo Verde species. He collected and planted seeds from the assorted trees he had observed and began evaluating them. By 1981 he had identified a thornless seedling as clearly superior to the others collected. Careful evaluation of the genetic composition of this hybrid, named 'Desert Museum', revealed it to be a complex hybrid having genetic characteristics from Mexican, Blue and Foothill Palo Verde. Dimmitt suspects that 'Desert Museum' gets it vigorous growth, sturdy, upright branching habit and bright flowers from P. aculeate, and its small delicate leaves from the Cercidium species. Trees have tolerated temperatures of 15 degrees without damage in Tucson. The most remarkable and unique feature of this hybrid is the absence of thorns. Flowers are slightly larger than those of P. aculeata and other Cercidiums and trees have been observed to flower abundantly as early as mid-March in southern Arizona with intense, full bloom lasting into late spring and early summer. Intermittent flowering can continue into the mid to late fall. Source: http://www.aridzonetrees.com

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*The green sticks in the place name Palos Verdes are thought to be the reeds that once surrounded the hill in the low lying (and navigable by canoe) marsh areas that are now parts of Lomita, Torrance, San Pedro, and other cities.

0.08" rain; seaon total 9.29"

On 9-Jun I received 0.08" of rain in my back yard for a season total of  9.29" of rain.  Once again, this is a totally normal number for Los Angeles, so if you had native plants in your garden instead of grass you wouldn't be overwhelmed with the water needs.

Rain 0.76"; 9.21" season total

We had a surprising amount of rain yesterday and overnight at my house: 0.7" and then a bit more on the following day.  This is quite late in the season for us to get this much rain - 75% of the time May has 0.25" or less rain in the LA area.  The rainfall total of 9.21" is normal for LA, which most frequently gets between 8 and 10 inches of rain per year.

If you have established native plants, they ought to do well in your garden this year with even a moderate amount of supplemental watering.  If you are establishing native plants, they will still need a bit of extra water to get through the summer.  Deep, infrequent, waterings are usually best.

Another 0.1" of rain; season total 8.45"

I predicted that we were done with rain for the year, but I was wrong. An overnight and early a.m. Storm gave us another 0.1" for a total of 8.45". This is not an unusual amount of rain for the Los Angeles area, so once again I say that this part of the state is having normal winter. If we landscaped with native plants we'd be sitting pretty in terms of keeping out yards alive.


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