Section 4
Comparison of Supply and Demand to Determine Needs
4.1 Water Needs Projections by Water User Group
For purposes of this regional planning project, and in accordance with TWDB Rules, water supply projections and water needs (shortages) projections are tabulated by river and coastal basin, county or part of county located within the river or coastal basin, and city and rural areas of each county or part of county for the South Central Texas Region (Tables 4-1 (4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-10 4-11 4-12 4-13 4-14 4-15 4-16 4-17 4-18 4-19 4-20 4-21) through 4-22 ).[1] For each county, the water demands by river and coastal basin and water user group were brought forward from “South Central Texas Region Water Management Plan — Introduction, Description of the Planning Region (Task 1) and Population and Water Demand Projections (Task 2), Table 2-12; South Central Texas Regional Water Planning Group, HDR Engineering, Inc., San Antonio, TX, August 1999.” These projected demands were compared to projected water supplies of Section 3, and if projected demands exceeded projected supplies for a water user group, the difference or shortage was identified as a water need for that water user group.
An illustration of how to read Tables 4-1 (4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-10 4-11 4-12 4-13 4-14 4-15 4-16 4-17 4-18 4-19 4-20 4-21) through 4-22 is given below; however, each table will not be verbalized here. For example, as shown in Table 4-1, a portion of Atascosa County is located in the Nueces River Basin, and a portion is located in the San Antonio River Basin. That part of Atascosa County located in the Nueces River Basin contains the cities of Charlotte, Jourdanton, Lytle, Pleasanton, and Poteet. In addition, rural areas of Atascosa County are located in the Nueces River Basin. The projected municipal water demand for Lytle is 559 acft in 2000 and 811 acft in 2050, while the projected municipal water supply for Lytle is 234 acft in 2000 and 234 acft in 2050 (Table 4-1). [Section 3.3 describes the methodology of computing water supplies for water user groups.] Comparing the projected demands with the projected supplies for Lytle in Atascosa County results in a shortage (need) of 325 acft in 2000 and 577 acft in 2050. Since the other cities of Atascosa County are projected to have more water supplies than demands, they have surpluses as opposed to needs.
Total projections for counties and parts of counties of each river and coastal basin area located in the South Central Texas Region are shown at the end of each county’s supplies and needs analysis table. The total projected water supplies available to Atascosa County in 2000 are 51,486 acft, of which 50,786 acft is located in the Nueces Basin and 700 acft is located in the San Antonio Basin. The counties projected water supplies are shown by river basin for each decade of the planning period (Table 4-1). This type of analysis is shown for each water user group for each county located within the South Central Texas Region.
The basin totals are listed in Table 4-22. For example, total water supply in the Nueces River Basin is projected to be 352,655 acft in 2000, of which 41,087 acft is for municipal purposes, 3,864 acft is for industrial purposes, 22,400 is for steam-electric power purposes, 218,245 acft is for irrigation purposes, 3,327 acft is for mining purposes, 8,942 acft is for livestock purposes, and 54,790 acft is unallocated groundwater supplies (Table 4-22). In 2000, the Nueces River Basin part of the South Central Texas Region is projected to have an irrigation water shortage of 309,465 acft and a mining shortage of 182 acft and in 2050 is projected to have a municipal water shortage of 2,366 acft, an irrigation shortage of 270,870 acft, and a mining shortage of 1,438 acft (Table 4-22). The reader can readily see the projections for water demand, water supply, and projected surplus/shortage, by type of demand, for the Nueces, San Antonio, Guadalupe, Colorado, Lavaca, and Rio Grande River Basin areas as well as the Colorado-Lavaca, Lavaca-Guadalupe, and the San Antonio-Nueces Coastal Basin areas of the South Central Texas Region (Table 4-22).
Total projected water supply in the South Central Texas Region in 2000 is 1,241,453 acft and in 2050 is 1,094,887 acft (Table 4-22). The projected water supply in 2050 is 319,379 acft for municipal use, 221,937 acft for industrial use, 123,279 acft for steam-electric use, 259,887 acft for irrigation use, 4,566 acft for mining use, 28,521 acft for livestock use, and 137,318 acft of unallocated groundwater. In 2050, the South Central Texas Region is projected to have a municipal water shortage of 450,144 acft, an industrial surplus of 19,558 acft, a steam-electric power shortage of 3,381 acft, an irrigation shortage of 256,461 acft, a mining shortage of 9,742 acft and a livestock surplus/shortage of 0 acft (Table 4-22). Of the 189 water user groups of the region with projected demand (104 municipalities and rural domestic users, 16 industry groups, 8 steam-electric users, 20 counties with irrigation use, 20 counties with mining water use, and 21 counties with livestock use), it has been calculated that 66 user groups will have a need sometime during the 50-year projection period. Of the estimated 66 user groups showing needs, 47 are municipalities or rural areas, four are industrial groups, two are steam-electric power groups, seven irrigation groups, and six mining groups.
4.2 Water Needs Projections by Major Water Provider
For purposes of this regional planning project, and in accordance with TWDB Rules, water supply projections and needs projections are tabulated for each Major Water Provider identified by the South Central Texas RWPG (Table 4-23).[2] For each Major Water Provider the water demands were brought forward from “South Central Texas Region Water Management Plan; Introduction, Description of the Planning Region (Task 1) and Population and Water Demand Projections (Task 2), Table 2-13; South Central Texas Regional Water Planning Group, HDR Engineering, Inc., San Antonio, TX, August 2000.”
Of the six Major Water Providers identified by the South Central Texas RWPG, five (SAWS, BMWD, CRWA, NBU, and the City of San Marcos) are projected to have a water shortage during the planning period (Table 4-23).
4.3 Social and Economic Impacts of Not Meeting Projected Water Needs
Section 357.7(4) of the rules for implementing Senate Bill 1 requires that the social and economic impact of not meeting regional water supply needs be evaluated by the SCTRWPG. TWDB is required to provide technical assistance, upon request, to complete the evaluations. SCTRWPG requested technical assistance of TWDB to perform the required analyses. TWDB conducted the required analysis of the impacts of the identified needs for the South Central Texas Region using the same methodology that was used for all other regions.
The purpose of this element of Senate Bill 1 planning is to provide an estimate of the social and economic importance of meeting projected water needs or, conversely, provides estimates of potential costs of not meeting projected needs of each water user group. The social and economic effects of not meeting a projected water need can be viewed as the potential benefit to be gained from implementing a strategy to meet the particular need. The summation of all the impacts gives a view of the ultimate magnitude of the impacts caused by not meeting all of the projected needs.
The projected total water demands for the South Central Texas Region increase from 1.32 million acft in 2000 to 1.50 million acft in 2030, and 1.66 million acft in 2050 (Table 2-10). Under historic drought of record water supply conditions, and with no water management strategies in place, water shortages amount to 495,000 acft/yr in 2000, increasing to 670,900 acft/yr in 2030 and to 785,700 acft/yr by 2050 (Table 4-24).
The water needs (shortages) of the region amount to about 39 percent of the projected demand by 2020, increasing to 47 percent in 2040, and to 48 percent in 2050. This means that by 2050 the region would be able to supply only 54 percent of the projected water demands unless supply development or other water management strategies are implemented.
The SCTRWPG
identified 66 individual water user groups that showed an unmet need during
drought-of-record supply conditions for each decade from 2000 to 2050 (Table 4-24). Of the 21 counties of the South Central
Texas Region, 14 have water user groups with projected water needs
(shortages). The water user groups
having projected water needs, together with the quantities of projected needs
(shortages), are listed by county and river basin of location in the region (Table 4-24).[3] For example, the projected municipal needs
for the City of Lytle (Atascosa
County) in the Nueces River Basin are 325 acft/yr in 2000, 467 acft/yr in 2030, and 577 acft/yr in 2050 (Table 4-24). The projected needs for irrigation in Atascosa County in the Nueces River Basin are 37,557 acft/yr in 2000 and for Atascosa County in the San Antonio River Basin in 2000 are 861 acft/yr, bringing the year 2000 projected need for irrigation water in Atascosa County to 38,418 acft/yr (Table 4-24). The projected water needs for irrigation in Atascosa County in 2030 are 43,726 acft/yr, of which 42,812 acft/yr are in the Nueces River Basin and 914 acft/yr are in the San Antonio River Basin (Table 4-24). The total projected need for Atascosa County in 2050 is 51,043 acft/yr, of which 50,210 acft/yr are in the Nueces River Basin, and 833 acft/yr are in the San Antonio River Basin (Table 4-24).
The water user groups having projected
water needs (shortages) of Atascosa, Bexar, Caldwell, Calhoun, Comal, Dimmit,
Frio, Guadalupe, Hays, Kendall, Medina, Uvalde, Wilson, and Zavala Counties are
tabulated in Table 4-24,
with summaries by user group, river basin, and the entire region presented at
the end of the table. For example, the
projected need (shortage) for the region is 670,946 acft/yr in 2030, of which
314,332 acft/yr is in the Nueces River Basin, 301,581 acft/yr is in the San
Antonio River Basin, and 54,181 acft/yr is in the Guadalupe River Basin (Table 4-24). Of the total projected need in 2030 of
670,946 acft/yr, 335,943 acft/yr is for municipal purposes, 2,913 acft/yr is
for industrial purposes, 920 acft/yr is for steam-electric power generation,
318,644 acft/yr is for irrigation, and 12,526 acft/yr is for mining purposes (Table 4-24). The quantities for each county and river
basin are shown in Table 4-24
and will not be repeated in the text.
The detailed results of the social and
economic analyses of not meeting the projected water needs (shortages) are
shown in Tables 4-24
(4-25
4-26 4-27)
through 4-28
. Each water user group with a need is
evaluated in terms of effects upon population,
school enrollment, gross business, employment, and personal income (see
Methodology in Supplement at end of subsection 4.3). Both the direct and indirect social and economic impacts on the
region resulting from the shortage were calculated. The effects of shortages on population and school enrollments are
the social variables of the analysis.
Declining populations indicate a deprecation of social services in most
cases, while declining school enrollment indicates loss of younger cohorts of the
population and possibilities of strains on the tax bases, when combined with
economic losses. Economic variables
chosen by TWDB for this analysis
include gross economic output (sales and business gross income), employment
(number of jobs), and personal income (wages, salaries, and proprietors net
receipts).
The regional effects upon population,
school enrollment, gross value of business, employment, and personal incomes are stated below. The
values for individual water user groups, counties, and river basins are shown
in Table 4-24
for population, Table 4-25
for school enrollment, Table 4-26
for gross business value, Table 4-27
for employment, and Table 4-28
for personal income.
Population: The projected population growth of the region would be economically restricted by curtailed potential job creation. This would result in out-migration of some current population, reduced migration, and reduced future population growth. Compared to the baseline growth in population, the region could expect 807,923 fewer people in 2010, 1.30 million fewer in 2030, and 2.00 million fewer in 2050 (Table 4-24). The expected 2050 population under the unmet water need (shortage) conditions would be 44 percent lower than projected in the region’s most likely growth projection.
School Enrollment: School enrollment is related to the size of the population of childbearing age, which is dependent upon employment, as mentioned above. Failure to meet the projected water needs of the region, such that employment opportunities are affected, would result in lower population and reduced school enrollment. School enrollment estimates for the region are 206,369 less in 2010, 328,528 less in 2030, and 500,891 less in 2050 than if the projected water needs are met (Table 4-25).
Gross Business Value: The estimated effect of water shortages projected for the South Central Texas Region upon gross value of business, which includes the direct and indirect effects, are $31.9 billion per year in 2010, $52.4 billion per year in 2030, and $78.8 billion per year in 2050 (Table 4-26). The economic impact of unmet water needs varies depending on the water user group for which the shortage is projected. On a per acre-foot basis, the largest impacts result from shortages in manufacturing and municipal uses, while shortages for irrigation typically result in the smallest impact. Impacts for individual water user groups are shown in Table 4-26.
Employment Effect: The estimated effect of water shortages upon employment in the region is 461,698 jobs in 2010, 748,081 jobs in 2030, and 1.10 million jobs in 2050 (Table 4-27).
Personal Income Effect: Failure to meet the projected water needs would result in an estimated loss of personal income of $12.96 billion in 2010, $21.02 billion in 2030, and $31.14 billion in 2050 (Table 4-28).
The largest percentage of the economic and social impacts of unmet water needs in the South Central Texas Region results from municipal water shortages. In 2010, municipalities have unmet needs of 198,198 acft—38 percent of the total unmet needs. The economic impacts of this shortage (456,069 jobs, $31.4 billion in output, and $12.8 billion of income) represent about 98 percent of the total impacts (Tables 4-27, 4-26, and 4-28, respectively). By 2050, unmet municipal needs total 475,466 acft (60.5 percent of the total) resulting in 1.04 million jobs not created, reductions of $72.3 billion in potential output, and $29.3 billion in potential income (Tables 4-27, 4-26, and 4-28).
Unmet irrigation needs represent the largest category of need through 2030 but, due to the relatively small value of economic output added per acre-foot, the impacts of not meeting irrigation needs are considerably less. In 2010, irrigation has unmet needs of 308,275 acft, 59 percent of the total. The economic impacts of the shortage (1,710 direct and indirect jobs, $66.9 million in output, and $19.8 million in income) represent less than one-half of 1 percent of the total economic impact (Tables 4-27, 4-26, and 4-28, respectively).
The impact of not meeting manufacturing needs increases with each decade. In 2010, manufacturing has unmet needs of 1,201 acft, 0.23 percent of the total unmet needs. The economic impacts of this shortage include loss of 3,172 jobs (0.7 percent of the total employment impact) and $370 million in output (1.16 percent of the total output impact). In 2050, unmet manufacturing needs are 10,640 acft (1.4 percent of the total) resulting in 53,423 jobs not created, and reduction of $6.2 billion in output (7.9 percent of the total output impact) (Tables 4-27, 4-26, and 4-28).
If the water needs are left entirely unmet, the level of shortage in 2010 results in 461,698 fewer jobs than would be expected if the water needs of 2010 are fully met. The gap in job growth due to water shortages grows to 748,081 by 2030 and to 1.1 million by 2050.
The potential loss of economic production in the region amounts to about 37 percent less income to people in 2010, with the gap growing to 44 percent less than expected in 2030. By 2050 the region would have 51 percent less income than is currently projected, assuming no water restrictions.
[1] 31 Texas Administrative Code, Chapter 357, Regional Water Planning Guideline Rules, Texas Water Development Board, Austin, Texas, March 11, 1998.
[2] 31 Texas Administrative Code, Chapter 357, Regional Water Planning Guideline Rules, Texas Water Development Board, Austin, Texas, March 11, 1998.
[3]
If there is no water user group that has a projected water need (shortage) in a
county, then that county is not listed in Table 4-24. The following counties of the South Central
Texas Region that did not have water user groups with projected water needs are
DeWitt, Goliad, Gonzales, Karnes, La Salle, Refugio, and Victoria.