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July 3, 2011

MSWD Board Meeting - UWMP - June 28

Urban Water Management Plan

You can download a copy of the Urban Water Management Plan here.

The Urban Water Management Plan must be updated every five years. The first paragraph of the document:

An Urban Water Management Plan (UWMP or Plan) prepared by a water purveyor is intended to demonstrate reliability of water service sufficient to meet the needs of its various categories of customers during normal, single dry or multiple dry years. The California Water Management Planning Act of 1983 (Act), as amended, requires urban water suppliers to develop an UWMP every five years in the years ending in zero and five. Under normal circumstances, all 2010 UWMPs would have been due for submittal to the Department of Water Resources (DWR) by December 31, 2010; however, Senate Bill (SB) 7-7 (or SBX7-7) provided an additional six months to retail urban water supply agencies to allow them to conduct additional required water conservation analyses. Thus, the District's 2010 UWMP must now be adopted by July 1, 2011 and submitted to DWR within 30 days of adoption.

Mike Swan from PSOMAS Engineering presented the plan to the board. There were major changes mandated by the state this year. The two most important were SBX7-7 which "sets an overall goal of reducing per capita urban water use by 20% by December 31, 2020;" and a requirement that low income housing demands be reported separately. Mr. Swan said he had been having trouble getting information from the city of Desert Hot Springs on low income housing. He said he was going over to the city later that day. He has been leaving messages with Martín Magaña, but hasn't heard back.

The 20% reduction in per capita water use, which they call "20x2020" includes these three requirements:

  • Baseline water use (gallons per capita per day) needs to be developed.
  • 2020 and 2015 water conservation target developed using one of four methods.
  • Public hearings on how to achieve the targets and financial impacts.

Baseline water use is determined by measuring the TOTAL water entering the distribution system, but excluding recycled water, agricultural water, water delivered into long-term storage and water conveyed to another retailer. None of those exceptions apply to MSWD.

Here are methodologies that may be used to determine baseline water use:

  • 10-year average for a ten-year period ending no earlier than 2004 and no later than 2010.
  • 15-year average, if 10% of demand in 2008 was met by recycled water [doesn't apply to MSWD].
  • Minimum 5-year average, if...
    • Ending no earlier than 2007 and no later than 2010.
    • if 100 gal/capita/day, then no further reduction is required.
    • If more than 100 gal/capita/day then a 5% reduction is required.

He presented this table of baseline water use from 1996 through 2010.
MSWD Baseline Water Use

The figures in the second column are pumped water in acre-feet/year. Here are charts illustrating the three columns on the right.

Water Use (Gallons/Day)
Total water use in gallons per day

Population Chart
. This has not yet been updated to reflect the 2010 census.

Water Use Per Capita (Gallons/Day)
Water use per capita in gallons per day.

Some of the water included in the chart and graphs above is construction water. The UWMP law does not allow that to be excluded.

There are four methods by which the 20% reduction target can be determined:

  1. 20% reduction from baseline.
  2. 55 gpcd indoor + landscape @ 70% evapotranspiration + 10% reduction of commercial-industrial-institutional demands. This requires the water purveyor to know how many square feet of landscaped area is on each lot. Mr. Swan said he doesn't know of any agency using this method, and there are only a few agencies who have the data that would allow them to use it.
  3. 5% reduction of DWR hydrologic region target. For us in the Colorado River Region that would put our goal at 200.5 gpcd.
  4. DWR's Best Management Practices method. DWR provides an Excel spreadsheet calculator for this.

Method 2 cannot be used in MSWD, but these would be the targets using the other three methods:
1. 261.7 gpcd
3. 200.5 gpcd
4. 264.9 gpcd

You want to come up with the highest baseline, because that will make it easier to achieve. Referring to the chart above you will see that we have already been meeting the 2020 goals since 2008.

Mr. Swan provided a table of inflows and outflows of the Mission Creek Sub-basin. Figures are in acre-feet/year.

From Desert Hot Springs Sub-basin - 1,800
From septic and irrigation return flows - 2,900
From Horton WWTP and Desert Crest WWTP infiltration ponds - 1,000
From mountain front recharge and stream underflow - 10,500
Artificial recharge (Worsley Road facility) (average 2002-2009) - 7,300

Underflow to Garnet Hill Sub-basin - 7,400
Underflow to semi-water-bearing rocks in SE portion of MC Sub-basin - 3,500
Pumpage - 1,400
Evapotranspiration - 1,400

Annual Balance - 4,300 net outflow.

Vice President Bowman asked how we know how much flows from the hot water (Desert Hot Springs) sub-basin into the cold water (Mission Creek) sub-basin. The simple answer is "modeling." The information for the modeling comes from the Water Management Plans for those two sub-basins. Mr. Bowman asked if the district has monitoring wells in the Desert Hot Springs Sub-basin. General Manager Wallum said no. Brent Gray said that MSWD has proposed two monitoring wells in the Desert Hot Springs Sub-basin.

Mr. Bowman asked what the percentage of accuracy was on the model. Mr. Swan said it's not a science, it's an art. He speculated it would have a 10% error range.

Here's a graph showing projected water demand.
MSWD Demand Projections
The darker blue (left hand) columns are the projections made in 2005. The lighter blue (right hand) columns have been adjusted for the slump in the economy and are the new projections out to 2035.

Supply and demand:
MSWD Normal Year Supply & Demand
Supply consist of 40,000 acre-feet in the aquifer. Starting by 2020, it is assumed that the district will be recycling 2,000 acre-feet, which would give us a total supply of 42,000.

Conservative projections for 2015 and 2020:

Groundwater (AF)14,30014,400
Recycled Water (AF)02,000
Gross Water Use (AF)14,30012,400
Water Use/Capita (gal/day)309.2231.6
Target Use/Capita (gal/day)296.0264.0

The formula allows us to subtract recycled water from the overall water use, which makes it the key to hitting the target in 2020.

MSWD Water Balance
The 2005 and 2010 numbers for Mission Creek Sub-basin Recharge are real. Those are two years in which a LOT of water was recharged. We can't expect that every year. Mr. Wallum pointed out the surplus of 24,900 last year is equivalent to more than six years of the loss of 3,700 AF/year projected for 2015.

The final recommendations were to continue to encourage conservations, to seek funding for a recycled water project, and monitor per capita consumption annually to see if conservation is a permanent feature of our community or if it's just an effect of the economic downturn.

Director Furbee said the future should not be viewed through the glasses of pessimism. He expects more growth.

Mr. Wallum recommended reading the full UWMP document for a good understanding of how water is moved around in California.

The plan was adopted by a vote of 5-0.

General Manager Comments

Mr. Wallum said his interview in the Desert Sun would be delayed until next week.

Director Comments

Director Wright praised the quality of this year's UWMP.

Director Martin was pleased to find two pages of acronyms and abbreviations in the UWMP that he said would have been helpful when he first joined the board.

He said he had received the annual water report in the mail. He questioned whether every citizen reads it, and whether it has to be mailed to everyone. He thinks the content of the report could be made more understandable. He said the least educated among our population should be able to understand what the water district is trying to say. Director Wright said that she owns property in Texas and she just got their water quality report, and it reads exactly the same as MSWD's. The text is dictated by federal law. Federal law also requires it to be mailed to every household. The only things that vary from water purveyor to water purveyor are the numbers and the appearance of the document.

Vice President Bowman said he really appreciated the employee luncheon that all the directors attended last week. He said you can't beat the esprit de corps of the MSWD employees.

Filed under Desert Hot Springs | permalink | July 3, 2011 at 09:26 AM


You need to find something else to do with your time then attend all these meetings...

Posted by: DHS at Jul 5, 2011 12:35:30 AM

With respect to my comments on the Annual Water Report. The information in the report could have been included with the monthly bill thus saving postage. Federal guidelines offer a number of options for notifying those who are consumers, not customers (renters for example) which would also cut printing and mailing costs.
Having said that, the savings would be minimal. The Annual Water Report is an impressive looking document which illustrates the professionalism of MSWD. Considering the challenges facing the district in November, I withdraw any constructive cost saving criticisms I may have entertained.

Posted by: Russ Martin at Jul 3, 2011 2:31:09 PM

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