Municipal water use - Revision history

JeffreyJLukas: /* Overview */

2026-05-18T21:43:20Z

Overview

← Older revision		Revision as of 17:43, 18 May 2026
Line 7:		Line 7:
	While the U.S. cities that depend in full or in part on Colorado River water have, with few exceptions, experienced rapid population growth over the last 20-30 years, per capita water use has broadly and significantly declined over that same period. The work by Richter (2023) linked in ''Data and tools'' below indicates that Denver and other large cities in Colorado reduced their per capita water use by 20-40% from 2000 to 2020, with similar reductions in Salt Lake City (30%), Albuquerque (40%), the Phoenix area and Tucson (10-30%), and southern California (30-40%), and greater Las Vegas (47%). For most of these cities, this per-capita reduction has exceeded population growth, and ''overall'' water use, from all sources, has declined since 2000.		While the U.S. cities that depend in full or in part on Colorado River water have, with few exceptions, experienced rapid population growth over the last 20-30 years, per capita water use has broadly and significantly declined over that same period. The work by Richter (2023) linked in ''Data and tools'' below indicates that Denver and other large cities in Colorado reduced their per capita water use by 20-40% from 2000 to 2020, with similar reductions in Salt Lake City (30%), Albuquerque (40%), the Phoenix area and Tucson (10-30%), and southern California (30-40%), and greater Las Vegas (47%). For most of these cities, this per-capita reduction has exceeded population growth, and ''overall'' water use, from all sources, has declined since 2000.

	The recent change in these cities' total use of water specifically from the Colorado River is more mixed, since a number of them have shifted their sources since 2000 and have become ''more'' reliant on Colorado River water (e.g., several Phoenix suburbs, Tucson, San Diego), while other cities have shifted sources away from the Colorado River (e.g., greater Los Angeles). In aggregate, municipal use of the Colorado River, at least in the U.S., has stayed relatively constant since 2000 ~~(see Figure 1 in [[Consumptive uses and losses]])~~ even as the total population served by the river's water increased by over 20%. But this can also be put the other way: ~~basin~~-wide, population growth and ~~the shifting of~~ water sources ~~has~~ canceled out the gains from widespread reductions in per-capita water use.		The recent change in these cities' total use of water specifically from the Colorado River is more mixed, since a number of them have shifted their sources since 2000 and have become ''more'' reliant on Colorado River water (e.g., several Phoenix suburbs, Tucson, San Diego), while other cities have shifted sources away from the Colorado River (e.g., greater Los Angeles). In aggregate, municipal use of the Colorado River, at least in the U.S., has stayed relatively constant since 2000 even as the total population served by the river's water increased by over 20%. But this can also be put the other way: Basin-wide, population growth and shifts in water sources have canceled out the gains from widespread reductions in per-capita water use.

	The municipal use of water is highly seasonal, with a pronounced peak in the warm season, since about half of all municipal use is used to irrigate plants--grass lawns, trees, and other urban greenery. This component of municipal use, like agricultural use, is sensitive to weather and climate, typically increasing during warmer, drier periods if not checked by municipal restrictions or other constraints. Further warming of the climate will tend to drive municipal outdoor use upwards, as [[evapotranspiration (ET)]] losses increase, in the absence of changes in watering practices or the extent and type of urban greenery.		The municipal use of water is highly seasonal, with a pronounced peak in the warm season, since about half of all municipal use is used to irrigate plants--grass lawns, trees, and other urban greenery. This component of municipal use, like agricultural use, is sensitive to weather and climate, typically increasing during warmer, drier periods if not checked by municipal restrictions or other constraints. Further warming of the climate will tend to drive municipal outdoor use upwards, as [[evapotranspiration (ET)]] losses increase, in the absence of changes in watering practices or the extent and type of urban greenery.

	The effects of climate change notwithstanding, further reductions in municipal per-capita use may occur through the broader implementation of conservation measures such as "cash for grass" (payments for lawn removal), permanent restrictions on watering, and direct reuse of wastewater.		The effects of climate change notwithstanding, further reductions in municipal per-capita use may occur through the broader implementation of conservation measures such as "cash for grass" (payments for lawn removal), permanent restrictions on watering, and direct reuse of wastewater.

	==Cities using Colorado River water ==		==Cities using Colorado River water ==

JeffreyJLukas: /* California */

2023-11-25T19:02:49Z

California

← Older revision		Revision as of 15:02, 25 November 2023
Line 33:		Line 33:

	===California===		===California===
	More people receive municipal water from Colorado River ~~water~~ in California than in any other state. Metropolitan areas served by the Colorado River Aqueduct managed by the Metropolitan Water District of Southern California, including greater Los Angeles and San Diego, have used between 0.5 and 1.1 million acre-feet of Colorado River water per year in the period 2017-2021, with the amount of use depending on the yield from other water sources. The Coachella Valley Water District and Imperial Irrigation District, while primarily serving agricultural use, also deliver water to numerous municipal water agencies in their respective valleys.		More people receive municipal water from the Colorado River in California than in any other state. Metropolitan areas served by the Colorado River Aqueduct managed by the Metropolitan Water District of Southern California (MWD), including greater Los Angeles and San Diego, have used between 0.5 and 1.1 million acre-feet of Colorado River water per year in the period 2017-2021, with the amount of use largely depending on the yield from MWD's other water sources. The Coachella Valley Water District and Imperial Irrigation District, while primarily serving agricultural use, also deliver water to numerous municipal water agencies in their respective valleys.

	===Mexico===		===Mexico===

JeffreyJLukas: /* California */

2023-11-25T19:01:55Z

California

← Older revision		Revision as of 15:01, 25 November 2023
Line 33:		Line 33:

	===California===		===California===
	More people ~~use~~ Colorado River water in California than in any other state. Metropolitan areas served by the Colorado River Aqueduct managed by the Metropolitan Water District of Southern California, including greater Los Angeles and San Diego, have used between 0.5 and 1.1 million acre-feet of Colorado River water per year in the period 2017-2021, with the amount of use depending on the yield from other water sources. The Coachella Valley Water District and Imperial Irrigation District, while primarily serving agricultural use, also deliver water to numerous municipal water agencies in their respective valleys.		More people receive municipal water from Colorado River water in California than in any other state. Metropolitan areas served by the Colorado River Aqueduct managed by the Metropolitan Water District of Southern California, including greater Los Angeles and San Diego, have used between 0.5 and 1.1 million acre-feet of Colorado River water per year in the period 2017-2021, with the amount of use depending on the yield from other water sources. The Coachella Valley Water District and Imperial Irrigation District, while primarily serving agricultural use, also deliver water to numerous municipal water agencies in their respective valleys.

	===Mexico===		===Mexico===

JeffreyJLukas at 22:18, 8 February 2023

2023-02-08T22:18:28Z

← Older revision		Revision as of 18:18, 8 February 2023
Line 11:		Line 11:
	The municipal use of water is highly seasonal, with a pronounced peak in the warm season, since about half of all municipal use is used to irrigate plants--grass lawns, trees, and other urban greenery. This component of municipal use, like agricultural use, is sensitive to weather and climate, typically increasing during warmer, drier periods if not checked by municipal restrictions or other constraints. Further warming of the climate will tend to drive municipal outdoor use upwards, as [[evapotranspiration (ET)]] losses increase, in the absence of changes in watering practices or the extent and type of urban greenery.		The municipal use of water is highly seasonal, with a pronounced peak in the warm season, since about half of all municipal use is used to irrigate plants--grass lawns, trees, and other urban greenery. This component of municipal use, like agricultural use, is sensitive to weather and climate, typically increasing during warmer, drier periods if not checked by municipal restrictions or other constraints. Further warming of the climate will tend to drive municipal outdoor use upwards, as [[evapotranspiration (ET)]] losses increase, in the absence of changes in watering practices or the extent and type of urban greenery.

	The effects of climate change notwithstanding, further reductions in municipal per-capita use ~~appear likely~~ through the broader implementation of conservation measures such as "cash for grass" (payments for lawn removal), permanent restrictions on watering, and direct reuse of wastewater~~. There is also a movement in some basin states towards tighter coupling of land-use planning and water provision, e.g., new developments must demonstrate access to sustainable water supplies~~.		The effects of climate change notwithstanding, further reductions in municipal per-capita use may occur through the broader implementation of conservation measures such as "cash for grass" (payments for lawn removal), permanent restrictions on watering, and direct reuse of wastewater.

	==Cities using Colorado River water ==		==Cities using Colorado River water ==

JeffreyJLukas: /* Overview */

2023-01-30T20:13:57Z

Overview

← Older revision		Revision as of 16:13, 30 January 2023
Line 9:		Line 9:
	The recent change in these cities' total use of water specifically from the Colorado River is more mixed, since a number of them have shifted their sources since 2000 and have become ''more'' reliant on Colorado River water (e.g., several Phoenix suburbs, Tucson, San Diego), while other cities have shifted sources away from the Colorado River (e.g., greater Los Angeles). In aggregate, municipal use of the Colorado River, at least in the U.S., has stayed relatively constant since 2000 (see Figure 1 in [[Consumptive uses and losses]]) even as the total population served by the river's water increased by over 20%. But this can also be put the other way: basin-wide, population growth and the shifting of water sources has canceled out the gains from widespread reductions in per-capita water use.		The recent change in these cities' total use of water specifically from the Colorado River is more mixed, since a number of them have shifted their sources since 2000 and have become ''more'' reliant on Colorado River water (e.g., several Phoenix suburbs, Tucson, San Diego), while other cities have shifted sources away from the Colorado River (e.g., greater Los Angeles). In aggregate, municipal use of the Colorado River, at least in the U.S., has stayed relatively constant since 2000 (see Figure 1 in [[Consumptive uses and losses]]) even as the total population served by the river's water increased by over 20%. But this can also be put the other way: basin-wide, population growth and the shifting of water sources has canceled out the gains from widespread reductions in per-capita water use.

	The municipal use of water is highly seasonal, with a pronounced peak in the warm season, since about half of all municipal use is used to irrigate plants--grass lawns, trees, and other urban greenery. This component of municipal use, like agricultural use, is sensitive to weather and climate, typically increasing during warmer, drier periods if not checked by municipal restrictions or other constraints. Further warming of the climate will tend to drive municipal outdoor use upwards, as [[evapotranspiration (ET)]] losses increase, in the absence of changes in watering practices or the extent and type of urban greenery.		The municipal use of water is highly seasonal, with a pronounced peak in the warm season, since about half of all municipal use is used to irrigate plants--grass lawns, trees, and other urban greenery. This component of municipal use, like agricultural use, is sensitive to weather and climate, typically increasing during warmer, drier periods if not checked by municipal restrictions or other constraints. Further warming of the climate will tend to drive municipal outdoor use upwards, as [[evapotranspiration (ET)]] losses increase, in the absence of changes in watering practices or the extent and type of urban greenery.

	The effects of climate change notwithstanding, further reductions in municipal per-capita use appear likely through the broader implementation of conservation measures such as "cash for grass" (payments for lawn removal), permanent restrictions on watering, and direct reuse of wastewater. There is also a movement in some basin states towards tighter coupling of land-use planning and water provision, e.g., new developments must ~~prove~~ sustainable water supplies~~. As overall basin supplies tighten, cities are brought into greater tension with agricultural users, who in many cases have more senior rights on the same reach or tributary that cities divert from~~.		The effects of climate change notwithstanding, further reductions in municipal per-capita use appear likely through the broader implementation of conservation measures such as "cash for grass" (payments for lawn removal), permanent restrictions on watering, and direct reuse of wastewater. There is also a movement in some basin states towards tighter coupling of land-use planning and water provision, e.g., new developments must demonstrate access to sustainable water supplies.

	==Cities using Colorado River water ==		==Cities using Colorado River water ==

JeffreyJLukas: /* Arizona */

2023-01-30T16:16:29Z

Arizona

← Older revision		Revision as of 12:16, 30 January 2023
Line 27:		Line 27:

	===Arizona===		===Arizona===
	Virtually all of Arizona is within the Colorado River Basin. The major cities in central and southern Arizona primarily receive water deliveries from the Central Arizona Project (CAP; Phoenix area and Tucson) and the Salt River Project (SRP; Phoenix area). Although the Salt River is a tributary of the Colorado River, ~~these~~ water uses do not administratively count towards Arizona’s Colorado River allocation.		Virtually all of Arizona is within the Colorado River Basin. The major cities in central and southern Arizona primarily receive water deliveries from the Central Arizona Project (CAP; Phoenix area and Tucson) and the Salt River Project (SRP; Phoenix area). Although the Salt River is a tributary of the Colorado River via the Gila River, SRP's water uses (and supplies) do not administratively count towards Arizona’s Colorado River allocation.

	===Nevada===		===Nevada===

JeffreyJLukas: /* Municipalities using Colorado River water */

2023-01-30T16:14:12Z

Municipalities using Colorado River water

← Older revision		Revision as of 12:14, 30 January 2023
Line 13:		Line 13:
	The effects of climate change notwithstanding, further reductions in municipal per-capita use appear likely through the broader implementation of conservation measures such as "cash for grass" (payments for lawn removal), permanent restrictions on watering, and direct reuse of wastewater. There is also a movement in some basin states towards tighter coupling of land-use planning and water provision, e.g., new developments must prove sustainable water supplies. As overall basin supplies tighten, cities are brought into greater tension with agricultural users, who in many cases have more senior rights on the same reach or tributary that cities divert from.		The effects of climate change notwithstanding, further reductions in municipal per-capita use appear likely through the broader implementation of conservation measures such as "cash for grass" (payments for lawn removal), permanent restrictions on watering, and direct reuse of wastewater. There is also a movement in some basin states towards tighter coupling of land-use planning and water provision, e.g., new developments must prove sustainable water supplies. As overall basin supplies tighten, cities are brought into greater tension with agricultural users, who in many cases have more senior rights on the same reach or tributary that cities divert from.

	==~~Municipalities~~ using Colorado River water ==		==Cities using Colorado River water ==
	===Colorado===		===Colorado===
	The vast majority of the municipal water use of the Colorado River within Colorado occurs out-of-basin, in the Front Range urban area that is anchored by Denver. About 300,000 acre-feet of water are diverted annually from the headwaters of the Colorado River and conveyed east across the Continental Divide to cities spanning from Fort Collins and Greeley south to Pueblo. Within the basin, virtually all towns and cities on Colorado’s Western Slope rely on water from the Colorado River or its tributaries, including Durango, Montrose, and Grand Junction.		The vast majority of the municipal water use of the Colorado River within Colorado occurs out-of-basin, in the Front Range urban area that is anchored by Denver. About 300,000 acre-feet of water are diverted annually from the headwaters of the Colorado River and conveyed east across the Continental Divide to cities spanning from Fort Collins and Greeley south to Pueblo. Within the basin, virtually all towns and cities on Colorado’s Western Slope rely on water from the Colorado River or its tributaries, including Durango, Montrose, and Grand Junction.

JeffreyJLukas: /* Overview */

2023-01-30T16:13:12Z

Overview

← Older revision		Revision as of 12:13, 30 January 2023
Line 7:		Line 7:
	While the U.S. cities that depend in full or in part on Colorado River water have, with few exceptions, experienced rapid population growth over the last 20-30 years, per capita water use has broadly and significantly declined over that same period. The work by Richter (2023) linked in ''Data and tools'' below indicates that Denver and other large cities in Colorado reduced their per capita water use by 20-40% from 2000 to 2020, with similar reductions in Salt Lake City (30%), Albuquerque (40%), the Phoenix area and Tucson (10-30%), and southern California (30-40%), and greater Las Vegas (47%). For most of these cities, this per-capita reduction has exceeded population growth, and ''overall'' water use, from all sources, has declined since 2000.		While the U.S. cities that depend in full or in part on Colorado River water have, with few exceptions, experienced rapid population growth over the last 20-30 years, per capita water use has broadly and significantly declined over that same period. The work by Richter (2023) linked in ''Data and tools'' below indicates that Denver and other large cities in Colorado reduced their per capita water use by 20-40% from 2000 to 2020, with similar reductions in Salt Lake City (30%), Albuquerque (40%), the Phoenix area and Tucson (10-30%), and southern California (30-40%), and greater Las Vegas (47%). For most of these cities, this per-capita reduction has exceeded population growth, and ''overall'' water use, from all sources, has declined since 2000.

	The recent change in these cities' total use of water specifically from the Colorado River is more mixed, since a number of them have shifted their sources since 2000 and have become ''more'' reliant on Colorado River water (e.g., several Phoenix suburbs, Tucson, San Diego), while other cities have shifted sources away from the Colorado River (e.g., greater Los Angeles). In aggregate, municipal use of the Colorado River, at least in the U.S., has stayed relatively constant since 2000 even as the total population served by the river's water increased by over 20% ~~(see Figure 1 in [[Consumptive uses and losses]])~~. But this can also be put the other way: basin-~~wise~~, population growth and the shifting of water sources has canceled out the gains from widespread reductions in per-capita-water use.		The recent change in these cities' total use of water specifically from the Colorado River is more mixed, since a number of them have shifted their sources since 2000 and have become ''more'' reliant on Colorado River water (e.g., several Phoenix suburbs, Tucson, San Diego), while other cities have shifted sources away from the Colorado River (e.g., greater Los Angeles). In aggregate, municipal use of the Colorado River, at least in the U.S., has stayed relatively constant since 2000 (see Figure 1 in [[Consumptive uses and losses]]) even as the total population served by the river's water increased by over 20%. But this can also be put the other way: basin-wide, population growth and the shifting of water sources has canceled out the gains from widespread reductions in per-capita water use.

	The municipal use of water is highly seasonal, with a pronounced peak in the warm season, since about half of all municipal use is used to irrigate plants--grass lawns, trees, and other urban greenery. This component of municipal use, like agricultural use, is sensitive to weather and climate, typically increasing during warmer, drier periods if not checked by municipal restrictions or other constraints. Further warming of the climate will tend to drive municipal outdoor use upwards, as [[evapotranspiration (ET)]] losses increase, in the absence of changes in watering practices or the extent and type of urban greenery.		The municipal use of water is highly seasonal, with a pronounced peak in the warm season, since about half of all municipal use is used to irrigate plants--grass lawns, trees, and other urban greenery. This component of municipal use, like agricultural use, is sensitive to weather and climate, typically increasing during warmer, drier periods if not checked by municipal restrictions or other constraints. Further warming of the climate will tend to drive municipal outdoor use upwards, as [[evapotranspiration (ET)]] losses increase, in the absence of changes in watering practices or the extent and type of urban greenery.

JeffreyJLukas: /* Overview */

2023-01-27T15:47:41Z

Overview

← Older revision		Revision as of 11:47, 27 January 2023
Line 3:		Line 3:
	[[File: MunicipalUse.png\|thumb\|500px\|'''Figure 1.''' Major cities within the Colorado River Basin, and outside of the basin (red hatching), that receive at least part of their municipal water supply from the Colorado River and its tributaries. (Source: Figure ES-1 in [https://pacinst.org/wp-content/uploads/sites/2013/02/crb_water_8_21_2011.pdf Municipal Deliveries of Colorado River Basin Water], M. Cohen, Pacific Institute, 2011)]]		[[File: MunicipalUse.png\|thumb\|500px\|'''Figure 1.''' Major cities within the Colorado River Basin, and outside of the basin (red hatching), that receive at least part of their municipal water supply from the Colorado River and its tributaries. (Source: Figure ES-1 in [https://pacinst.org/wp-content/uploads/sites/2013/02/crb_water_8_21_2011.pdf Municipal Deliveries of Colorado River Basin Water], M. Cohen, Pacific Institute, 2011)]]

	Colorado River municipal water use (i.e., residential, commercial, industrial, and institutional uses within towns and cities, ''aka'' municipal and industrial or M&I) accounts for about 25% of the beneficial uses of the Colorado River and about 20% of all consumptive uses and losses. These municipal uses occur in both cities within the Colorado River Basin such as Las Vegas, Phoenix, and St. George, UT, and in many cities outside the physical watershed, including Denver, Salt Lake City, Los Angeles, and Tijuana. Of the 40 million people receiving at least some of their municipal water from the Colorado River, an estimated 70% live outside of the river basin, mostly in Southern California, and so that water is delivered via trans-basin diversions. Nearly all of these cities outside the watershed use additional water sources and do not rely entirely on the Colorado River and its tributaries.		Colorado River municipal water use (i.e., residential, commercial, industrial, and institutional uses within towns and cities, ''aka'' municipal and industrial or M&I) accounts for about 25% of the beneficial uses of the Colorado River and about 20% of all [[consumptive uses and losses]]. These municipal uses occur in both cities within the Colorado River Basin such as Las Vegas, Phoenix, and St. George, UT, and in many cities outside the physical watershed, including Denver, Salt Lake City, Los Angeles, and Tijuana. Of the 40 million people receiving at least some of their municipal water from the Colorado River, an estimated 70% live outside of the river basin, mostly in Southern California, and so that water is delivered via trans-basin diversions. Nearly all of these cities outside the watershed use additional water sources and do not rely entirely on the Colorado River and its tributaries.

	While the U.S. cities that depend in full or in part on Colorado River water have, with few exceptions, experienced rapid population growth over the last 20-30 years, per capita water use has broadly and significantly declined over that same period. The work by Richter (2023) linked in ''Data and tools'' below indicates that Denver and other large cities in Colorado reduced their per capita water use by 20-40% from 2000 to 2020, with similar reductions in Salt Lake City (30%), Albuquerque (40%), the Phoenix area and Tucson (10-30%), and southern California (30-40%), and greater Las Vegas (47%). For most of these cities, this per-capita reduction has exceeded population growth, and ''overall'' water use, from all sources, has declined since 2000.		While the U.S. cities that depend in full or in part on Colorado River water have, with few exceptions, experienced rapid population growth over the last 20-30 years, per capita water use has broadly and significantly declined over that same period. The work by Richter (2023) linked in ''Data and tools'' below indicates that Denver and other large cities in Colorado reduced their per capita water use by 20-40% from 2000 to 2020, with similar reductions in Salt Lake City (30%), Albuquerque (40%), the Phoenix area and Tucson (10-30%), and southern California (30-40%), and greater Las Vegas (47%). For most of these cities, this per-capita reduction has exceeded population growth, and ''overall'' water use, from all sources, has declined since 2000.

JeffreyJLukas: /* Overview */

2023-01-27T15:46:49Z

Overview

← Older revision		Revision as of 11:46, 27 January 2023
Line 3:		Line 3:
	[[File: MunicipalUse.png\|thumb\|500px\|'''Figure 1.''' Major cities within the Colorado River Basin, and outside of the basin (red hatching), that receive at least part of their municipal water supply from the Colorado River and its tributaries. (Source: Figure ES-1 in [https://pacinst.org/wp-content/uploads/sites/2013/02/crb_water_8_21_2011.pdf Municipal Deliveries of Colorado River Basin Water], M. Cohen, Pacific Institute, 2011)]]		[[File: MunicipalUse.png\|thumb\|500px\|'''Figure 1.''' Major cities within the Colorado River Basin, and outside of the basin (red hatching), that receive at least part of their municipal water supply from the Colorado River and its tributaries. (Source: Figure ES-1 in [https://pacinst.org/wp-content/uploads/sites/2013/02/crb_water_8_21_2011.pdf Municipal Deliveries of Colorado River Basin Water], M. Cohen, Pacific Institute, 2011)]]

	Colorado River municipal water use (i.e., residential, commercial, industrial, and institutional uses within towns and cities, ''aka'' municipal and industrial or ''M&I'') accounts for about 25% of the beneficial uses of the Colorado River and about 20% of all consumptive uses and losses. These municipal uses occur in both cities within the Colorado River Basin such as Las Vegas, Phoenix, and St. George, UT, and in many cities outside the physical watershed, including Denver, Salt Lake City, Los Angeles, and Tijuana. Of the 40 million people receiving at least some of their municipal water from the Colorado River, an estimated 70% live outside of the river basin, mostly in Southern California, and so that water is delivered via trans-basin diversions. Nearly all of these cities outside the watershed use additional water sources and do not rely entirely on the Colorado River and its tributaries.		Colorado River municipal water use (i.e., residential, commercial, industrial, and institutional uses within towns and cities, ''aka'' municipal and industrial or M&I) accounts for about 25% of the beneficial uses of the Colorado River and about 20% of all consumptive uses and losses. These municipal uses occur in both cities within the Colorado River Basin such as Las Vegas, Phoenix, and St. George, UT, and in many cities outside the physical watershed, including Denver, Salt Lake City, Los Angeles, and Tijuana. Of the 40 million people receiving at least some of their municipal water from the Colorado River, an estimated 70% live outside of the river basin, mostly in Southern California, and so that water is delivered via trans-basin diversions. Nearly all of these cities outside the watershed use additional water sources and do not rely entirely on the Colorado River and its tributaries.

	While the U.S. cities that depend in full or in part on Colorado River water have, with few exceptions, experienced rapid population growth over the last 20-30 years, per capita water use has broadly and significantly declined over that same period. The work by Richter (2023) linked in ''Data and tools'' below indicates that Denver and other large cities in Colorado reduced their per capita water use by 20-40% from 2000 to 2020, with similar reductions in Salt Lake City (30%), Albuquerque (40%), the Phoenix area and Tucson (10-30%), and southern California (30-40%), and greater Las Vegas (47%). For most of these cities, this per-capita reduction has exceeded population growth, and ''overall'' water use, from all sources, has declined since 2000.		While the U.S. cities that depend in full or in part on Colorado River water have, with few exceptions, experienced rapid population growth over the last 20-30 years, per capita water use has broadly and significantly declined over that same period. The work by Richter (2023) linked in ''Data and tools'' below indicates that Denver and other large cities in Colorado reduced their per capita water use by 20-40% from 2000 to 2020, with similar reductions in Salt Lake City (30%), Albuquerque (40%), the Phoenix area and Tucson (10-30%), and southern California (30-40%), and greater Las Vegas (47%). For most of these cities, this per-capita reduction has exceeded population growth, and ''overall'' water use, from all sources, has declined since 2000.