§ 3.0. Water conservation goals.

Municipal per capita water use is defined by the TCEQ as "the sum total of water diverted into a water supply system for residential, commercial, public and institution uses divided by the actual population served". In Irving, municipal per capita water use includes industrial water sales though we anticipate having the ability to show industrial use separately in future conservation plan updates. It is common to use municipal per capita water use for water supply/conservation planning and to assess the long-term effectiveness of water conservation programs. However, the inclusion of industrial water sales diminishes the applicability of the municipal gpcd statistic. At this point, examination of the trend in residential water use will be more useful to provide an indication of the effectiveness of the city's water conservation program.

Regardless of the effectiveness of this water conservation plan, municipal per capita water use in Irving is expected to increase in the future. This is because residential growth and related water use in Irving is expected to increase substantially less than the amount of non-residential growth and its related water use. The 2008 Comprehensive Plan Update includes a future land use plan which has been accepted by the Irving City Council. The intent of the updated comprehensive plan is to promote land use in a sustainable form, work toward more cohesive development and to improve mass pedestrian and mass transit connectivity in the community. Based on the comprehensive plan, about one-third ( 1/3 ) of the remaining developable land in Irving will be for residential or mixed use developments, and about two-thirds ( 2/3 ) of the remaining developable land will be for commercial, office, retail, and light industrial uses. This ratio of future residential land use to non-residential land use is substantially less than the ratio between existing residential and non-residential land uses.

Because of the anticipated mix of future development, commercial/industrial water uses are expected to increase much more than residential/apartment water uses. This will cause overall municipal per capita water use to increase. As a result, it is anticipated that municipal per capita water use may not show the long-term effectiveness of the city's water conservation efforts and the municipal gpcd is not expected to decrease at the same rate as the residential gpcd. Based on this, municipal gpcd goals are less aggressive than residential gpcd goals as shown in the chart below.

In keeping with this line of thought, Irving residential water use should be a better barometer than total municipal use to gauge future water use changes on a per capita basis. Over the past five (5) years, residential per capita water use (including apartments) has ranged from ninety-eight (98) gallons per capita per day (gpcd) to one hundred twenty-three (123) gpcd. The average residential per capita use during these five (5) years has been 107.6 gpcd. The goal is to reduce the residential water use as shown in the following table.

Table 3.1 Current and Historical Water Use Goals and Projected Per Capita Use

2004 - 2008 Water Use Vs. Current Goals	Previous 5 Years 2004-2008		2004-2008 Goal	5-Year Goal 2009-2013	10-Year Goal 2014-2018
	Year	Gpcd	Gpcd	Gpcd	Gpcd
Highest Residential Per Capita Use	2005-06	123	127	123	117
Average Residential Per Capita Use		108	116	112	107
Highest Municipal Per Capita Use	2005-06	202	230	219	219
Average Municipal Per Capita Use 1, 2		176	212	202	202

 

 

2000 - 2004 Water Use Vs. Previous Goals	Historical 5 Years 2000-2004		5-Year Goal 2004-2008	10-year Goal 2009-2013
Highest Residential Per Capita Use	1999-00	130	127	123
Average Residential Per Capita Use		118.6	116	112
Highest Municipal Per Capita Use	1999-00	230	230	230
Average Municipal Per Capita Use 1, 2		212.2	212	212
Notes: The number listed is an average for a span of the five fiscal years indicated. Irving's municipal per capita use includes industrial sales since it could not be separated in previous billing system. Values (gpcd) will increase in the future despite water conservation due to projected higher commercial/industrial growth.

 

Importantly, the city was able to exceed expectations by recording lower gpcd residential and municipal rates than targeted. With regard to residential use, this achievement can be largely attributed to the emphasis on water conservation due to drought conditions which have persisted during the previous five (5) years. Because the ten-year goal levels for residential use were met for the previous five-year time span, the future five-year and ten-year goals have been set at a one (1) percent per year rate of decrease. With consistent public education and media application regarding water conservation, the city hopes to continue the positive trend.

The expectation for municipal per capita use is more conservative. As noted above, the five-year data shows a significant drop. During the past five (5) years, the municipal per capita water use ranged from one hundred sixty (160) gpcd to two hundred two (202) gpcd with an average of 175.8 gpcd. Based on current city land-use planning, as indicated earlier, these numbers will almost certainly increase in the future despite water conservation because two-thirds ( 2/3 ) of development will be commercial or industrial, and they may increase even with water conservation efforts. Therefore, the established five-year goal allows for some improvement, but represents only a small change in order to accommodate the higher level of commercial/industrial development. For the ten-year goal, the intention is to maintain water use at the reduced target level.

The city's water conservation goals include the following:

• Reduce the highest residential per capita use to one hundred seventeen (117) gpcd. Reduce average residential per capita use to one hundred seven (107) gpcd.

• Drop the highest and average municipal per capita use by one (1) percent per year over five (5) years and hold at that level through the ten-year timeframe (over time, levels are expected to increase with or without water conservation).

• Continue the meter replacement program as discussed in section 5.2.

• Maintain level of unaccounted water below 10 percent as discussed in section 5.3.

• Build the existing leak detection program and surveys of the water distribution system to include a comprehensive plan for system review every five (5) years.

• Persist in the use of a water conservation coordinator to continue implementation of and sustain a comprehensive conservation program including the components discussed in this report as well as others deemed appropriate.

• Encourage and promote replacement of plumbing fixtures with water conserving fixtures and appliances.

• Emphasize the use of water conserving landscaping and responsible irrigation of such landscaping by educating the public and enforcing recently passed ordinances regarding these items and promotion of alternative watering methods such as rainwater harvesting.

• Raise public awareness of water conservation and encourage responsible public behavior through a public education and information program as discussed in section 5.4.

(Ord. No. 2011-9302, § 1, 12-8-11)