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ENGINEERS  PLANNERS  PROJECT MANAGERS

VIEWS: 4 PAGES: 9

									                                                                                                 TECHNICAL
                                                                                               MEMORANDUM
ENGINEERS  PLANNERS  PROJECT MANAGERS
400 West 15th Street, Suite 500
Austin, Texas 78701
(512) 472-4519
FAX (512) 472-7519




TO:    Rio Grande Regional Water        FROM:       Connie M. Hinojos for        PAGE            1     OF            6
       Planning Group (RWPG)                        Mike Personett
                                                                                                 Plus three appendices
SUBJECT:         Evaluation of Advanced Water Conservation For Municipal         JOB NO.:      37-00501-002
                 User Groups as a Water Management Strategy

                                                                                 DATE:        June 6, 2000


This project memorandum presents a summary of the evaluation of a water management strategy that would accelerate the
water conservation efforts by municipal water users within the Rio Grande Region from the currently approved Texas
Water Development Board (TWDB) “Expected Water Conservation Scenario” to the TWDB’s “Advanced Water
Conservation Scenario.”


TWDB WATER CONSERVATION SCENARIOS

The "Historical and Projected Population and Water Use Data for Regional Planning Groups", compiled by the Texas
Water Development Board (TWDB), provides water demand projections under various water conservation scenarios for
each municipal water user group (WUG) within each of the 16 planning regions. These scenarios are for "no
conservation", "expected conservation", and "advanced conservation." The municipal water demand projections adopted
by the Rio Grande Regional Water Planning Group (RWPG) and approved by the TWDB incorporates the “expected
conservation” scenario. The "expected conservation" scenario implements the replacement of plumbing fixtures in older
houses built on or before 1990 with those that meet the 1991 plumbing fixtures standards enacted in Texas Senate Bill
587. Approximately 50 percent of new homes built between 1990 and 1999 are assumed to have fixtures that meet the
new plumbing fixture standards and all homes built after 1999 are assumed to comply with the new standards. By 2040
it is anticipated that 90 percent of existing homes will have been retrofitted. The “Expected Conservation” scenario
assumes the following measures will be implemented:
    1. The implementation of the plumbing fixtures legislation (SB 587), which will result in a savings of 20.5
       gallons/capita/day (gpcd) when compared to the current mix of existing fixtures (toilets, showerheads,
       faucets);
    2. Continuation of current water conservation education activities at current funding levels;
    3. Continuation of current TWDB requirements to develop water conservation programs as part of loan
       requirements; and,
    4. Current and expected future levels of effort in the areas of leak detection, commercial water conservation,
       and trends in home appliance water use.

The "advanced conservation" scenario includes all of the measures of the "expected conservation" scenario. However, the
implementation of these measures occurs at an accelerated rate. Municipal water use is divided into three categories:
“plumbing fixtures retrofit”, “seasonal” (or “outdoor”) water use, and “other” municipal water demand factors. “Other”
municipal factors include commercial and utility conservation, public education, and the improved water-use efficiencies
of appliances. The “Advanced Conservation” scenario assumes the following measures will be implemented:


Rio Grande Regional Water Plan                                                                  January 2001
Adopted Regional Water Plan                                                                                                Technical Memorandum
Page 2 of 6

   1. The institution of a plumbing fixtures retrofit rebate program to save 21.7 gpcd (as is now being done
      successfully in many cities in California);
   2. Mandatory implementation of water conservation programs by all cities and utilities in Texas;
   3. Development of required landscape irrigation ordinances for all cities (as is now required in California);
   4. Intensified programs to promote commercial water conservation;
   5. Increased water audit/leak detection services by the State and regional water authorities;
   6. Required labeling of clothes washers and dishwashers with water use data and conservation information;
   7. A statewide water conservation education effort with funding similar to the "Don't Mess With Texas"
      program; and,
   8. A requirement that all utilities develop water conservation-oriented rate structures.

Measures 1 and 7 accelerate the time when plumbing retrofits and fixture replacements are accomplished (95% complete
timeframe from 2040 to 2030). “Outdoor” savings requires the use of measures 2, 3, 7, and 8. “Other” savings require
the use of measures 2, 4, 5, 6, and 7. Table 1 shows the key assumptions used for the “expected conservation” and
“advanced conservation” scenarios. Table 2 shows the percent savings and the timing of the TWDB water conservation
scenarios.

Table 1: Comparison of Assumptions for "Expected" and "Advanced" TWDB Municipal Water Conservation Scenarios
           Category                     Expected Conservation                                      Advanced Conservation1
                       New Standards result in 20.5 gpcd savings                   New Standards result in 21.7 gpcd savings

                       50 % of population increases between 1990 an 1999 in 35 % of population increases between 2000 an 2009 in
                       homes with older fixtures.                           homes with older fixtures.

           Plumbing    All population increases after 2000 in homes with new                                  same
           Fixtures    fixtures.

                       18 % of 1990 and earlier homes are retrofitted with new 30% of 2000 and earlier homes are retrofitted with new
                       fixtures each decade so that 90 % are retrofitted by    fixtures each decade so that 90 % are retrofitted by
                       2040.                                                   2030.

                       7 % of average seasonal use is saved.                       20 % of average seasonal use is saved.

         Seasonal2,3 10.5 % of drought outdoor use is saved.                       20 % of drought outdoor use is saved.
       (Drought Year) 1/3 of savings occurs by year 2000, 2/3 by 2010, and                                    same
                       100% by 2020-2040.

            Other      5 % savings of average per capita use compared to no        7.5 % savings of average per capita use compared to no
           Factors     conservation.                                               conservation.
       Source: Texas Water Development Board
       1
        The advanced conservation program has been modified from the TWDB methodology to start approximately one decade after the expected
       conservation begins (instead of simultaneously).
       2
        Texas average seasonal use is defined by the TWDB as 20% of the average annual normal weather condition gpcd (12-year average between
       1977-1988).
       3
        Texas drought condition outdoor use is defined by the TWDB as the average seasonal use plus the difference between the average normal
       weather condition gpcd and the highest annual average gpcd during the 10-year period between 1979-1988.




Rio Grande Regional Water Plan                                                                                                        January 2001
Adopted Regional Water Plan                                                                                                        Technical Memorandum
Page 3 of 6


Table 2: Percent Savings and Timing of the TWDB Water Conservation Scenarios
                Category                 Expected Conservation                     Advanced Conservation1                    % Added Savings

       Plumbing Fixtures               18% each decade with 90%                   30% each decade with 90%                  12% (and 10 years)
           Retrofit                       completion in 2040.                        completion in 2030.
                                    10.5% of outdoor drought water 20% of outdoor drought water use
              Seasonal2,3                       use saved                             saved
                                                                                                                    9.5%
            (Drought Year)           1/3 of savings occurs by 1st decade, 2/3 by 2nd decade, and 100% during the last 10-30 years
                                      5 % savings of average gpcd               7.5 % savings of average gpcd
                                      compared to no conservation.               compared to no conservation.
                                            Commercial = 1.5%                   Commercial = 2.5%
                  Other                                                                                              2.5%
                                               Utility = 2.0%                      Utility = 2.5%
                 Factors
                                             Education = 1.0%                     Education = 1.5%
                                            Appliances = 0.5%                    Appliances = 1.0%
                                           1/3 of savings occurs by 1st decade, 2/3 by 2nd decade, and 100% by the 3rd decade
       Source: Texas Water Development Board
       1
        The advanced conservation program was modified from TWDB methodology to start approximately 1 decade after the expected conservation
       begins.
       2
           The average seasonal use is defined as 20% of the average annual normal weather condition gpcd (12-year average between 1977-1988).
       3
        The average outdoor drought water use is defined as the average seasonal use plus the difference between the average normal weather condition
       gpcd and the highest annual average gpcd during the 10-year period between 1979-1988.




REDUCTIONS IN MUNCIPAL WATER DEFICITS DUE TO IMPLEMENTATION OF THE
ADVANCED WATER CONSERVATION SCENARIO WITHIN THE RIO GRANDE REGION

The regional water planning groups have the option to provide updated population and water use information if they feel
the TWDB's projections are not accurate. For the Rio Grande Region (Region M) there are eight counties and 56
municipal water user groups. During the planning process, the Rio Grande Region adopted the "expected conservation"
scenario and population and water use projections were updated for this scenario. These revised projections have been
approved by the TWDB. To estimate the revised "advanced conservation" per capita water use rate, the same percent
decrease in per capita water use that exists between the TWDB's expected and advanced conservation per capita water use
rates was applied to the revised expected water use per capita rate for each municipal WUG within the Rio Grande
Region. In addition, the implementation schedule of advanced water conservation efforts was delayed approximately 10
years from the TWDB’s anticipated start date. Projections of the effects of the advanced water conservation scenario
were not prepared for municipal WUGs that do not show shortages during the planning period; nor for those
WUGs that would have attained a daily per capita water use rate below 115 gpcd during the planning period under
the “advanced conservation” scenario. This occurred because trying to attain significant additional water
conservation below this level is not a realistic expectation, which is a viewpoint shared by the TWDB. Previously,
two other RWPG’s (Regions C and O) have modified, with TWDB approval, the TWDB’s “expected conservation”
scenario to establish a floor of 115 gpcd for municipal water demand projections for these same reasons.

The Rio Grande Region is projected to experience water supply deficits throughout the entire planning period. Table 3
shows the reductions in projected water supply deficits for the Rio Grande Region between 2000 and 2050, due to the
implementation of advanced municipal water conservation efforts. Six of the eight counties within the Rio Grande
Region are active in the regional advanced municipal water conservation efforts, each county having one or more WUGs
participating. The sequential implementation of the phases of the advanced conservation program increases the effects of
the water savings achieved during the planning period. Annual water demand reductions increase from approximately
4,500 ac-ft/yr in 2010 to more than 22,600 ac-ft/yr in 2050. This corresponds to an overall decrease in the region’s water

Rio Grande Regional Water Plan                                                                                                                   January 2001
Adopted Regional Water Plan                                                                                            Technical Memorandum
Page 4 of 6

supply of more than 13 percent and 10 percent, respectively. Appendix A provides the detail of water demand
reductions for each participating WUG and county in the Rio Grande Region.

Table 3: Reduction of Water Demand Due to Implementation of Advanced Municipal Water Conservation
                                                                           Municipal Water User Group (WUG) Projections 1,2,3
     Regional Water Demand/Conservation Information
                                                                         2000     2010      2020     2030    2040        2050
Rio Grande Region:
Expected Conservation Water Demand (ac-ft/yr)                           226,201      265,955      310,313     372,952      410,788     454,394
Advanced Conservation Water Demand (ac-ft/yr)                           222,365      255,666      292,651     347,294      385,316     427,235
Expected Conservation Water Supply Deficit (ac-ft/yr)                   (12,281)     (33,831)    (68,718) (131,293) (171,112) (220,318)
Advanced Conservation Water Supply Deficit (ac-ft/yr)                   (12,281)     (29,329)    (58,152) (111,984) (150,253) (197,668)
                      Net Demand Reduction (ac-ft/yr)                          0        4,502      10,566    19,309    20,859    22,650
       Decrease in Regional Water Supply Deficit (%)                       -           13.3%       15.4%     14.7%     12.2%     10.3%
1
    negative numbers are in parentheses and are equal to the water supply deficit; deficit/surplus values are current as of 5-22-00.
2
 advanced conservation water demand values for each WUG were calculated as a percentage of the expected conservation case water
demand projections.
3
 the advanced conservation scenario was not applied to WUGs that would have attained a per capita water use rate <115 gpcd using
advanced conservation; nor to WUGs for which there is no deficit projected during the planning period.



IMPLEMENTATION COSTS FOR A REGIONAL MUNICIPAL ADVANCED WATER CONSERVATION
PROGRAM

Accurately deriving costs to establish and operate an active municipal water conservation program requires a site-specific
study to determine the characteristics of the current residential and commercial water users involved, the capacities of the
utilities providing water and wastewater services, and the ability of the region to finance the various program components.
For a reconnaissance-level estimation of the costs for the TWDB-required components of an advanced water conservation
program in the Rio Grande Region, the City of Houston’s 1997 Final Draft Water Conservation Plan was used as a guide.
The City of Houston has similar population projections to the Rio Grande Region, making it possible to extrapolate
program services to the Rio Grande planning region. The City of Houston’s plan used 1995 present value costs, which
have been updated to the ENR’s second quarter 1999 Construction Cost Index where appropriate, for the Rio Grande
regional advanced water conservation program. Table 4 lists the program components and associated costs for the Rio
Grande regional advanced water conservation plan during the 50-year planning period. Appendix B provides a
summary of the population statistical estimations for counties in the Rio Grande Region that were used in calculating
these program costs. Appendix C provides costing details for each program component.

Six of the eight counties within the Rio Grande Region are involved in the advanced water conservation efforts. The other
two counties, Jim Hogg and Maverick, are projected to participate in the level of water conservation prescribed by the
TWDB in the “expected water conservation” scenario. The WUGs within Jim Hogg County are not projected to have any
water supply deficits during the planning period. The WUGs within Maverick County either do not have water deficits
projected or their daily per capita water use falls below the established floor of 115 gpcd, as discussed previously. As
Table 4 shows, total water conservation program cost estimations are highest in 2010 (~$5M) and decline each
succeeding decade, down to approximately 2.7 million dollars in 2050. This corresponds to a per capita cost of $5 per
person and $2 per person, respectively, for those involved in the advanced water conservation efforts. The higher costs in
2010 are due to the startup costs associated with establishing the various components of the conservation program, which
then decrease to operation and maintenance costs in later decades. The low per capita costs for decreasing water demand
through advanced conservation make this one of the more attractive water management strategies available to the Rio
Grande Region.

Rio Grande Regional Water Plan                                                                                                   January 2001
Adopted Regional Water Plan                                                                                          Technical Memorandum
Page 5 of 6


Table 4: Cost Estimations (1999 Dollars) for an Advanced Municipal Water Conservation Program in the Rio Grande Region
                                                                                                                                                                                           Projections
                                                                                        Participating Portion of Rio Grande Region - Municipal Projections 1,2,3
       Water Demand & Water Conservation Information Categories 4                                                                                                                        Averaged Over
                                                                                        2000             2010            2020             2030             2040             2050         Planning Period

Participating Portion of the Rio Grande Region (6 of 8 counties are participating in advanced water conservation efforts):
Expected Conservation Regional Water Supply Deficit                     (ac-ft/yr)        (12,281)        (33,831)         (68,718)       (131,293)        (171,112)        (220,318)           (127,511)
Advanced Conservation Regional Water Supply Deficit                     (ac-ft/yr)        (12,281)        (29,329)         (58,152)       (111,984)        (150,253)        (197,668)           (111,934)
Regional Water Demand Reduction (Expected - Advanced) 5,6                  (ac-ft/yr)           0           4,502          10,566           19,309           20,859           22,650              15,577
Decrease in Regional Water Supply Deficit                                      (%)                          13.3%           15.4%            14.7%            12.2%            10.3%               12.2%
Estimated # Households in Participating Portion of Region                                208,843         258,199          314,254          386,537          427,123          478,255
Estimated # New Households in Participating Portion of Region                             30,117          49,355           56,056           72,283           40,586           51,132
Total Population of Cities/Counties Participating in Water Conservation Efforts           771,130         954,843        1,163,913        1,433,564        1,583,571        1,773,147         1,381,808
                                                               7,8
Estimated Total Annual Conservation Program Costs                     ($/yr)               -         $ 5,008,290     $ 3,527,306      $ 3,757,814      $ 3,022,941      $ 2,774,741           3,618,218
    Residential Indoor/Outdoor Water Audit Program                 ($/yr)                  -         $ 658,697       $ 746,810        $ 860,430        $ 755,665        $ 751,758               754,672
    Residential Plumbing Fixtures Retrofit Program                    ($/yr)               -         $ 984,423       $ 984,423        $ 984,423        $ 328,141        $         -             656,282
    Residential Appliance Labeling Program                            ($/yr)               -         $     6,786     $     8,259      $    10,159      $    11,225      $    12,569              48,998
    Public Education Program                                            ($/yr)             -         $ 424,122       $ 525,164        $ 640,152        $ 788,460        $ 870,964               649,772
    Commercial Indoor Water Audit/Equipment Rebate Program ($/yr)                          -         $ 123,200       $ 123,200        $ 123,200        $         -      $         -              73,920
    Commercial Plumbing Fixtures Retrofit Program                      ($/yr)              -         $ 1,501,500     $         -      $         -      $         -      $         -             300,300
    Commercial Outdoor Water Audit Program                           ($/yr)                -         $    25,488     $    20,000      $    20,000      $    20,000      $    20,000             105,488
    Landscape Irrigation Ordinance (commercial/multifamily)          ($/yr)                -         $ 153,650       $ 153,650        $ 153,650        $ 153,650        $ 153,650               153,650
    Utility System Leak Detection and Repair Program                ($/yr)                 -         $ 965,800       $ 965,800        $ 965,800        $ 965,800        $ 965,800               965,800
    Utility Water Conservation Rate Structure                       ($/yr)                 -         $ 164,625       $         -      $         -      $         -      $         -              32,925
Estimated Annual Program Unit Costs               ($/ac-ft water saved/yr)                 -         $      1,112    $          334   $          195   $          145   $          123   $           232
Estimated Per Capita Annual Program Costs                            ($/person/yr)         -         $          5    $            3   $            3   $            2   $            2   $             3
1
 negative numbers are in parentheses and are equal to the water supply deficit; deficit/surplus values are current as of 5-22-00.
2
 advanced conservation water demand values for each WUG were calculated as a percentage of the expected conservation case water demand projections.
3
 estimations of cost for this advanced conservation program are based on data from the City of Houston's Final Draft Water Conservation Plan, March 1997.
4
    see Tables 1 & 2 for assumptions used in determining water demands based on the TWDB's "Expected" and "Advanced" Water Conservation Scenarios.
5
    water conservation programs require extended timeperiods to realize the water saving benefits and are also influenced by implementation schedules.
6
    see Appendix A for the details of the water demand reductions for each participating WUG and county in the Rio Grande Region.
7
    see Appendix B for a summary of the population statistical estimations for counties in the Rio Grande Region that were used in calculating these program costs.
8
    see Appendix C for costing details for each program component.


Rio Grande Regional Water Plan                                                                                                                                               January 2001
Adopted Regional Water Plan                                                                          Technical Memorandum
Page 6 of 6



NON-WATER SUPPLY BENEFITS OF MUNICIPAL WATER CONSERVATION 1,2

Although the impacts of advanced municipal water conservation are difficult to quantify, there are both economic and
environmental benefits associated with implementing these conservation efforts. Valuing conservation benefits is much
more conceptual and can be described as “avoided costs.” Avoided costs include water supply, water treatment and
distribution, wastewater treatment, and energy consumption. There is also benefit from improved reliability and customer
service, increased water demand hardening, and decreased environmental degradation.

While advanced water conservation does not create “new” water supplies, it does extend the availability of existing water
supplies so as to delay or prevent the need for developing additional new water sources. Obtaining new water supplies
will always be more expensive than existing supplies. Conserving water also allows more water to remain available as a
natural resource for freshwater inflow and bay/estuary inflow needs, as well as decreasing the destruction of habitat for
water supply projects.

In addition to the capital-outlay cost savings associated with developing new water supply sources, this water
management strategy also saves money by deferring the expansion of water and wastewater facilities that would be
required to handle the increased water demands in the Rio Grande Region. This is especially true for the municipal
irrigation water conservation efforts because these significantly reduce the peak daily water demand, which in turn
determines the capacity required for the water treatment and distribution system. There is also an energy and materials
savings from the operation and maintenance that would have occurred at the expanded facility. Energy will also be
conserved at the point of service due to the plumbing fixture retrofits that will use less hot water.

System reliability is improved due to the increase in the buffer between supply and demand, which reduces the probability
of the occurrence of water shortages. Customer service will be improved as more emphasis is assigned to responses to
shortage emergencies by water agencies. There is also increased demand hardening as water is conserved on a regular
basis prior to a water shortage, which results in deferring the onset of a water shortage.

It is felt that the most efficient way to implement the TWDB’s municipal “advanced water conservation” scenario in the
Rio Grande Region is by a cooperative effort within the region. The establishment of a river authority would create a
regional agency that could implement and manage a well-organized and complementary municipal advanced water
conservation program throughout the region. Another approach would be to have the three state-designated Municipal
Statistical Areas (MSAs) within the Rio Grande Region administer the advanced water conservation programs. Private
contractors could also be engaged on a regional or county basis to manage the program and perform the conservation
tasks. It should also be noted that in lieu of paying for a site-specific water conservation study to better quantify the water
conservation efforts before implementation, an alternative approach would be for the various water and energy utilities
and municipal WUGs to develop a Memorandum of Agreement that establishes a specified series of conservation efforts
that everyone agrees to participate in and contribute a prescribed amount of funding to implement and manage those
efforts. This has been done successfully in several cities in the state of California and results in more money being
available for actual water conservation efforts rather than losing a portion of the funding to pre-program studies. There
has been a sufficient amount of research conducted in the United States and Canada to validate the benefits that advanced
municipal water conservation has to offer.




1
  Chesnutt, T.W., et.al., 1997. “Valuing Conservation”, Annual Conference Proceedings: American Water Works Association;
Volume B: Water Resources (Atlanta, Georgia; June 15-19, 1997).
2
  Cote, G., 1996. “Using Net Present Value to Make Conservation Pay”, Annual Conference Proceedings: American Water Works
Association; Volume B: Water Resources (Toronto, Ontario, Canada; June 23-27, 1996).

Rio Grande Regional Water Plan                                                                                January 2001
Adopted Regional Water Plan                                          Technical Memorandum




                                    APPENDIX A



Advanced Conservation Water Demand Projections and Water Supply Deficits for Municipal
       Water User Groups Within the Rio Grande Regional Water Planning Area




Rio Grande Regional Water Plan                                              January 2001
Adopted Regional Water Plan                                                Technical Memorandum




                                        APPENDIX B



            Population Statistical Estimations For Counties in the Rio Grande Region




Rio Grande Regional Water Plan                                                    January 2001
Adopted Regional Water Plan                                           Technical Memorandum




                                     APPENDIX C



  Estimated Costs for a Regional Advanced Water Conservation Program in the Rio Grande
                              Regional Water Planning Area




Rio Grande Regional Water Plan                                               January 2001

								
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