How To, Why To Save Water

Posted on | May 16, 2009 | No Comments


A Grace Phillips garden from

A Grace Phillips garden from

By Grace Phillips

RECENTLY, the Metropolitan Water District reduced water allocations to Southern California by about 20%. While we in Santa Monica are cushioned, the City will probably ask for further voluntary 10% reductions. That raises the question: Can you afford to reduce your water use? I have come to realize that it is very difficult for Santa Monica water users to answer that, because when you get your water bill, you have no way of knowing whether you are a good, careful water user, or a major water waster.  

So, I thought I would share some information to help you figure out what kind of water user you are, and some more information on how to be a better one. 

PART ONE: Some Interesting Factoids

  1. Santa Monica gets more than 80% of its water from far, far away. Pumping water up and over mountains and through the desert uses 30% of the state’s electricity, much of that provided by coal-fired power plants.
  2. In other words, getting us water is hugely polluting. 

  3. Getting new water from something like desalination is really, really expensive – like $16 per gallon expensive.

  4. Sixty to seventy per cent of single family home water use is on  landscaping.
Most homeowners over-water their gardens by 300%.

  5. Traditional sprinklers were designed for the sandiest, fastest-draining soil in the US, not for our slightly clay-like soil here in Southern CA. These sprinklers put out water three to five times faster than our soil can actually absorb it. 

  6. Santa Monica is fined by the Environmental Protection Agency for contaminants in the Bay,  60% of which come from sprinkler overspray and runoff hitting dirty streets on its way to the storm-drain. The fine is big, and we are paying for it.

  7. Sprinkler overspray and runoff (from things like hosing driveways) are  illegal, and can result in a $500 per day fine, accruing daily until  the problem is fixed. This is different from the water waste fee, which is a fine of $250 and up.

  8. Most older sprinklers lose up to 40% of the water that they put out to wind and evaporation. That mist you see when your  sprinklers are on is all lost water. 

  9. The city has issued about 5,500 water violation notices in its efforts to get residents to stop watering the streets and the Bay.
  10. For further reference, here is a good article from Water and Wastewater News.

PART TWO: How to Read Your Water Bill (when they don’t tell  you how much you should be using)

Get the bill and look at three things:

1. Usage/HCF

An HCF is a hundred cubic feet, a 10′ x 10′ x 1′ box of water, or 748 gallons. Let’s say your bill shows that your usage is 33 HCF (the average for Santa Monica). That  means you have used 33 x 748 = 24,684 gallons in this two-month billing period. That translates to 411 gallons per day, or 150,000  gallons per year.

Your toilet uses 1.6 gallons per flush. Your shower is about 2.5 – 5 gallons per minute. Your dishwasher probably uses between  7-12 gallons per cycle. Your clothes washer uses anywhere from 10-30 gallons.  At that rate, it is hard to get to 411 gallons/day unless you are using it outside. Bottom line, a family of four should be using  something like 125 – 150 gallons/day inside the house. Everything else is garden, leaks or waste.

2. Water Charges: Which tier are you in?

The tiers get more expensive as your usage goes up. Tier 1 is $1.65 per HCF for the first 14 HCF, Tier 2 is $2.47 per HCF for 15-40 HCF,  and Tier 3 is $3.70 per HCF for 41-148 HCF.  Obviously, if you are in Tier 1, you are in good shape. Tier 2 means you are moderate, and Tier 3 means you are a water hog (not to mince terms!)  

3. The Graph: It is rough, yes, but it still should contain cycles due to weather. So the scale of the graph changes depending on your bill. For example, the axis on the left of mine goes up to 700 gallons per day, while friends have scales up into the thousands. What you are looking for here is steep ups and downs depending on the months. July through September should be considerably higher than November through February. If your  graph is basically flat, it means that you are not adjusting your water use to the weather. Most likely, you are delivering July water to plants most of  the year. If your gardener is really good, you might have a chunky up and down.

The upshot: flat = bad, spiky = good.

PART THREE: How to Improve / Lower Your Water Use

Santa Monica got a break this time due to past good behavior, i.e. the MWD rewards our previous conservation by not cutting our allocation. But if we ever go into a water-saving advisory phase, residential use will be budgeted at something like 132 HCF per year.  If you are using 33 HCF per 2-month billing cycle, you are about 50% over. Rather than wait for emergency cut-backs, this is a great time for easy fixes, which will have the added benefit of achieving good marks to save the city from cuts next time.

A key easy fix is getting a weather-based irrigation controller (WBIC). That will save about 30% of your outdoor use, and won’t require  re-landscaping.

WBICs look like regular irrigation controllers, but they take current weather information and adjust your system to compensate. In the summer, when it’s hot, they water more. In the winter, when it rains, they turn the system off.  They will do this with no visible changes — except that the plants will be happier not  being drowned. 

To get a WBIC, you  just need to ask your landscaper or knowledgeable gardener. I have been a guinea pig installer for  the city’s landscape water folks, and the WBIC type I like best is from ETWater. These WBICs require a monthly download fee of a few dollars. You program them online, and then, if you are in Bora Bora, say, and you get a call from your neighbor that there’s a broken head, you can go online and suspend the system.

You can also go online and see when it will water next, how much rainfall there was last month, and other interesting stuff. Or the  gardener can learn to control the system at the box. These are available at AquaFlo (a local irrigation supply chain) and cost about $925 or from Imperial Irrigation for $640. (For exactly the same thing.)  It is sophisticated, but it is a great machine and will pay for itself over time. Besides that one, any WBIC that is approved by SWAT (Smart Water Application Technologies) should do the trick. 

The  second thing is to retrofit your traditional spray heads with MP Rotors. The  City will rebate this. They put out water more slowly, and in a rotating arc, so the ground has time to absorb it before runoff develops. The heads go right on your existing sprinklers, and are about $4 a piece.

And if you need help with the installation of either of these devices, the City of Santa Monica has a list of landscape installers who can do the job.

There are also City of Santa Monica grants of up to $5000 if you upgrade your  irrigation and remove lawn. 

Finally, the reason I’m writing this is that we, the customers, have to check our own bad habits. If we have gardeners maintaining our properties, then we have to ask them to get with the program too. That means not to use the hose as a broom or expecting your gardeners to suggest that you upgrade your own irrigation system. It’s not  your gardener’s job to save you water. Change has to come from customers reading the bill.

That’s my two cents.

Grace Phillips is owner of  Gracescapes, a Santa Monica landscape design firm. Those outside of Santa Monica should contact their local water authorities to investigate rebates offered in their areas.



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