Geoscience Reference
In-Depth Information
Considering perceptions at the neighborhood scale, the findings are very similar
to the household-level patterns.
In the aggregate analysis,
the majority of
neighborhoods (58%, or n
9) exhibited a disconnect between perceived water
use and actual demand rates, with most perceiving water use to be lower than it
actually is. While only 13% collectively overestimated the rate of demand relative
to actual metered usage rates, 45% of neighborhoods underestimated water use. For
the high-use neighborhoods in our intensive sample, all five exhibited perceptions
indicating low to typical rates of consumption. None of the neighborhoods in our
typology sample appeared to exhibit a shared awareness of relatively high water-
use rates locally, even though metered data reveals that a quarter were located in
areas with high consumption rates.
Moreover, all of the neighborhoods where perceived water use corresponded
with metered demand (44%) were located in areas with low to average consumption
rates. Statistically, perceptions and actual environmental conditions were not
correlated at either the individual level of residents (Spearman's rho
¼
¼
0.018,
p
¼
0.751) or the aggregate level of neighborhoods (Spearman's rho
¼
0.289,
p
0.278). The overall lack of a significant relationship between perceptions and
actual neighborhood water demand indicates that cognitive judgments may have a
tenuous influence on actual water use. Also, the small sample of neighborhoods
with both survey and metered data available limits our understanding of the
perception-outcome relationship, as discussed further below. Yet the patterns in
perceptions and actual water demand—generally and in relation to each other—are
informative, especially considering the structural factors that may explain neigh-
borhood water use.
Next, in order to further reveal determinants of water demand (beyond human
judgments), we complement our quantitative analysis of perceptions and actual
water demand with a typology of our 16 in-depth neighborhoods for which we have
both types of data. By characterizing local water use rates, related perceptions, and
structural determinants of demand, our approach informs targeted conservation
planning based on the factors most likely to influence water use and conservation
in residential neighborhoods, especially for 'hot spots' with excessive consumption.
¼
2.4.3 Typology of Neighborhood Water Demand
and Determinants
In linking perceptions and other critical determinants to water consumption—
namely, age of housing, annual median household income, and vegetative ground
cover, the high-demand neighborhoods (n
4) in our typology encompassed older
homes and higher income residents compared to areas with lower water-use rates
(Table
2.3
). The one low-income ($20-40,000) neighborhood with high water
demand was the oldest neighborhood in this category and the second oldest in the
typology sample (n
¼
16). Similar to other areas, and in spite of high local demand,
residents in the high water-demand neighborhoods exhibited the widespread
perception of low to normal consumption. The mismatch was most extreme
¼
