Designer’s Guide Confessions of a water waster


Timothy Allinson, P.E., Murray Co., Long Beach, Calif. I


n May, my family moved into a new home. Upon arrival, we discovered that the water had been turned off during the month-long escrow process. As a result, the land-


scaping was showing signs of water deprivation. I immedi- ately reprogrammed the irrigation controller to water gener- ously so that the landscaping would spring back to its former glory. In the interim, we discovered that our golden retriever


Bella was producing brown spots on the grass with her dog pee. It turns out that our new home’s beautiful sod was sen- sitive to the pH of her urine, a fact we did not previously know, since we had dog-friendly “faux grass” at our former home. In an attempt to combat this destructive problem, I left the irrigation settings of the sprinkler system in the “gen- erous” mode I initially programmed, with the hope that the water would dilute Bella’s urine and restore the brown spots. Months passed and our first utility bills started to arrive.


Water, despite our arid So Cal climate, has always been our least expensive utility bill, in the $20-odd range at our old house and the $40-odd range in our new home, the increase being expected with more landscaping. But not to worry, as it was still our cheapest utility. Then our August bill arrived and we were shocked. Suddenly, our bill was in excess of $120. It seems we missed a notification that the billing structure


of our water utility, the Moulton Niguel Water District, had changed dramatically in July. Since voluntary efforts toward water conservation had not achieved the desired result, the MNWD resorted to Plan B — hitting their customers in the wallet, and I’m sure it’s producing the intended results. The new water billing structure is a budget-based system.


Each household is given a water budget based on the num- ber of household members (four in our case) and the square footage of irrigated landscape. These two factors produce a billing unit (BU) budget, which varies by month due to sea- sonality. One BU is 100 cubic feet of water. The billing structure is then broken into tiers based around your water budget. In my case, for the month of August my water budget was


16 BUs. (In July it was 20 BUs.) My actual consumption was 26 BUs; that’s nearly 20,000 gallons of water in one month! Based on my water budget, my tiered billing sched- ule was as follows:


Conservation: 10 BUs @ $1.38 Efficient: Inefficient: Excessive: Wasteful:


6 BUs @ $1.54 4 BUs @ $2.75 4 BUs @ $5.51 2 BUs @ $11.02


The above, plus a basic water charge of $10.36, a basic


sewer charge of $11.14 and a sewer usage charge of 25 BUs @ $0.88 totaled $121.62. It’s interesting that there is a one BU credit in the sewer usage. I guess they assume that only one unit was used for irrigation, but that is a bad assumption. What bothered me most about the water bill was not the


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cost, but the fact that I had made it all the way to the top tier of Wasteful. As a plumbing engineer, this hit me where it hurts. But, to be honest, my irrigation schedule had been wasteful, and it is good that the MNWD is penalizing peo- ple for such behavior. I immediately reprogrammed my irri- gation controller for a 50% reduction; it will be interesting to find out how much of a difference that one change will make. I called the MNWD to speak with them about this billing structure, since I had many questions. First, I asked them how they determined the number of people in my home and was told that the information was taken from a recently con- ducted census. Next, I asked them how they determined my landscape area and was told that they have a satellite pro- gram similar to Google Maps that they use to take a mea- surement — pretty fancy and highly accurate. Then I asked them about the seasonality of the budget and why August had a lower budget allowance than July, when August is typ- ically the hotter month. I learned that the seasonality is based on actual weather data collected for the specific neighbor- hood, not the city as a whole. The MNWD has 110 weather monitoring stations in its


district that generate the weather related budget data for billing purposes —also fancy and accurate. Lastly, I asked why only one BU was figured for irrigation, and I was told that 25 is the maximum number of billing units they attribute to sewer, no matter how many more billing units you might use; it is not an irrigation assumption. This is the one aspect of their new billing structure that is inaccurate and needs fur- ther development. They know this and are working on it. Apparently, the MNWD is not the first water utility to use


such a billing structure. They developed their model based on a similar one that the Irvine Ranch Water District has been using for 19 years. I don’t know if the IRWD was the first to develop this model, but I would guess they were. Since starting this article I have received my August


MNWD Waterlines newsletter. In it the district claims that most customers already use water efficiently and have no trouble remaining within their water budget. Customers at risk of exceeding their water budget have been identified, and the district has been working closely with them to help reduce their water use and lower their water bills. This is not true, as I never received a phone call, and I would likely be near the top of their water-waster list. I imagine the former claim about most people being within their water budget is probably quite a stretch as well. In fairness, after speaking with the district about the


billing program, they offered to lower my August bill. This was not even the intent of my call, but they lowered it just the same.


Hopefully, my irrigation changes, coupled with some behavioral changes, will keep me within budget next month. I’ll keep you posted. n


The views and opinions expressed in this column are those of the author and do not reflect those of Plumbing Engineer nor its publisher, TMB Publishing.


October 2011


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