WaterWired

From RMSAWWA & RMWEA: How to Save the Colorado River and Other Tales

I just saw a copy of the November 2020 issue of the magazine Rocky Mountain Water, which is published by the Rocky Mountain Section of the AWWA and Rocky Mountain Water Environment Association. The issue has articles Impacts of Wildfires on Water Quality and Water Treatment (page 16) and How to Save the Colorado River (p. 25).

Download RMW__November_2020

Here is an electronic copy: click here.

I won't divulge the endings, but here is the last section of the Colorado River article.

Intuition vs. Facts

“The experiment is important to us,” Thompson said. “We want to make decisions based on the science and the data, not a gut feeling.”

Much of the work is grueling, like cutting hay samples week after week, and low tech, like measuring water levels in rain gauges.

But dramatic advances in satellite imagery and global evapotranspiration databases are helping people like Perry Cabot create science-based templates that eventually will be useful not just in Colorado, but Wyoming, Utah, New Mexico and perhaps even farther downstream, on cotton fields in Arizona and avocado groves in California’s Central Valley.

“We now have the ability to measure the whole field, ” Cabot said. “It’s becoming more accurate and it’s tremendously convenient if you’re trying to get a good understanding of patterns. We don’t have to rely on one data point anymore.” [Editor’s note: Cabot sits on the board of Water Education Colorado, which is a sponsor of Fresh Water News.]

Enjoy!

"He that will not apply new remedies must expect new evils." - Francis Bacon

Colorado River Blues Redux: Going, Going...Gone? (2008 --> 2021)

This is a repost of an article I published on 2 December 2008: Colorado River Blues: Going, Going...I did not intend to add 'redux' to the title and repost it until a few minutes ago. I read a Tweet from friend and colleague Michael van der Valk, who re-Tweeted the post preceding this one, Ground Water: The Water Budget Myth, one of my all-time favorites. I had been reading current depressing articles about water woes in the Colorado Basin. So I thought it might be enlightening to see what was occurring in late 2008. Some of the links may be broken. I added a CRB map, which was absent from the original post.

Interesting to see Wall Street's current interest in the CRB. Could The Water Knife be far behind? 

Enjoy! 

This post is appropriate, given that I am in Las Vegas for the NGWA's Ground Water Expo. The year 2008 marks the 60th anniversary of the NGWA. I'll be curious to see whether the economy affects attendance. The Expo is in Las Vegas every other year, and I think we broke 6,000 attendees in 2006.

I am staying at the venerable Las Vegas Hilton, which, when I arrived in Nevada 32 years ago, was the second-largest hotel in the world after a Moscow hotel. Now I doubt if it is in the Top 15 in Las Vegas, much less the world. That's how this town has changed. The State of Nevada had fewer than 500,000 residents when I arrived in 1976; now, the Las Vegas area alone has over 2 million.

But the LVH has kept up with the times, though - Barry Manilow is playing the showroom. Awesome, dude!

I'm ensconced in a huge suite on the third floor, all for just $125 per night. I'm not sure what I did to deserve this treatment. But I'm still being charged $13.99/24 hours for WiFi, so I guess I'm not THAT special.

Great seeing Kevin McRay, NGWA's Executive Director, and Brent Murray, chair of AGWSE, NGWA's largest division. Two good guys.

Sorry for the digression.

So here is the "appropriate" post, but it's is not good news. Bad enough the economy is tanking, but alas, the Colorado River is not doing much better, according to Patty Henetz's article, published in the 29 November 2008 edition of the Salt Lake Tribune.

Here are the first few paragraphs:

The drought gripping Utah, Southern California and the rest of the Southwest this century shows no sign of ending. Scientists see it as a permanent condition that, despite year-to-year weather variations, will deepen as temperatures rise, snows dwindle, soils bake and fires burn.

That's grim news for all of us in the West, perhaps most especially for the 10 million residents along the northern stretch of the Colorado River -- Utah, New Mexico, Wyoming and Colorado -- whose water rights are newer, and therefore junior, to those in Southern California, Nevada and Arizona.

Making matters worse, the Colorado -- the 1,450-mile-long lifeline that sustains more than 30 million souls and 3.5 million acres of farmland in seven states, 34 tribal nations and Mexico -- is in decline, scientists warn.

But the best is yet to come.

Dozens of scientific studies issued since 2004 have documented the Colorado's decline.

The river's annual flow has averaged 11.7 million acre-feet this decade, according to federal records. In 2002, the U.S. Bureau of Reclamation measured only 6.2 million acre-feet passing Lee's Ferry below Glen Canyon Dam, the lowest flow of the decade. Even after this year's above-average precipitation, Lake Powell and Lake Mead combined are at 57 percent capacity.

A 2007 U.S. Geological Survey report found that, by 2050, rising temperatures in the Southwest could rival those of the nation's fabled droughts, including the Dust Bowl of the 1930s. Hotter weather is expected to reduce Colorado River runoff by at least 30 percent during the 21st century.

If the USGS is correct, and if this century's trend persists, average annual flow in the Colorado could fall to 8.2 million acre-feet per year.

Imagine that. The Law of the River requires 9 million acre-feet to pass Lee's Ferry on the way to the Lower Basin and Mexico. Under a strict interpretation of the law, the Upper Basin could be left with nothing.

You can read the rest of the article. Even Peter Gleick and Pat Mulroy would not be able to make things right.

But at least Las Vegas is using less water these days.

Meanwhile, elsewhere in the CRB...I was in the Phoenix area (Tempe, actually) several weeks ago with some colleagues. At Arizona State University's remarkable Decision Theater we got a taste of high-tech decision-making. It is part of the Global Institute of Sustainability (GIOS).

We heard some interesting things, but one in particular made an impression on me. One of the folks told us that in the Greater Phoenix area, if you go to a local politician/water manager with a predictive model that shows a future with less precipitation, you're out of luck. They're not even thinking about that possibility. Heads in the sand, or what?

I think I am getting close to finding someone who is "thinking about the unthinkable" regarding Southwest water and depopulation, particularly in the Colorado River Basin.

"Las Vegas is Everyman's cut-rate Babylon.  Not far away there is, or was, a roadside lunch counter and over it a sign proclaiming in three words that a Roman emperor's orgy is now a democratic institution - 'Topless Pizza Lunch'."  ~Alistair Cooke

"Do you know what we call tourists in Las Vegas? We call them 'marks'." - desk clerk, San Remo Hotel, Las Vegas, NV

This is a repost of an article I published on 2 December 2008: Colorado River Blues: Going, Going...I did not intend to add 'redux' to the title and repost it until a few minutes ago. I read a Tweet from friend and colleague Michael van der Valk, who re-Tweeted the post preceding this one, Ground Water: The Water Budget Myth, one of my all-time favorites. I had been reading current depressing articles about water woes in the Colorado Basin. So I thought it might be enlightening to see what was occurring in late 2008. Some of the links may be broken. I added a CRB map, which was absent from the original post.

Interesting to see Wall Street's current interest in the CRB. Could The Water Knife be far behind? 

Enjoy! 

This post is appropriate, given that I am in Las Vegas for the NGWA's Ground Water Expo. The year 2008 marks the 60th anniversary of the NGWA. I'll be curious to see whether the economy affects attendance. The Expo is in Las Vegas every other year, and I think we broke 6,000 attendees in 2006.

I am staying at the venerable Las Vegas Hilton, which, when I arrived in Nevada 32 years ago, was the second-largest hotel in the world after a Moscow hotel. Now I doubt if it is in the Top 15 in Las Vegas, much less the world. That's how this town has changed. The State of Nevada had fewer than 500,000 residents when I arrived in 1976; now, the Las Vegas area alone has over 2 million.

But the LVH has kept up with the times, though - Barry Manilow is playing the showroom. Awesome, dude!

I'm ensconced in a huge suite on the third floor, all for just $125 per night. I'm not sure what I did to deserve this treatment. But I'm still being charged $13.99/24 hours for WiFi, so I guess I'm not THAT special.

Great seeing Kevin McRay, NGWA's Executive Director, and Brent Murray, chair of AGWSE, NGWA's largest division. Two good guys.

Sorry for the digression.

So here is the "appropriate" post, but it's is not good news. Bad enough the economy is tanking, but alas, the Colorado River is not doing much better, according to Patty Henetz's article, published in the 29 November 2008 edition of the Salt Lake Tribune.

Here are the first few paragraphs:

The drought gripping Utah, Southern California and the rest of the Southwest this century shows no sign of ending. Scientists see it as a permanent condition that, despite year-to-year weather variations, will deepen as temperatures rise, snows dwindle, soils bake and fires burn.

That's grim news for all of us in the West, perhaps most especially for the 10 million residents along the northern stretch of the Colorado River -- Utah, New Mexico, Wyoming and Colorado -- whose water rights are newer, and therefore junior, to those in Southern California, Nevada and Arizona.

Making matters worse, the Colorado -- the 1,450-mile-long lifeline that sustains more than 30 million souls and 3.5 million acres of farmland in seven states, 34 tribal nations and Mexico -- is in decline, scientists warn.

But the best is yet to come.

Dozens of scientific studies issued since 2004 have documented the Colorado's decline.

The river's annual flow has averaged 11.7 million acre-feet this decade, according to federal records. In 2002, the U.S. Bureau of Reclamation measured only 6.2 million acre-feet passing Lee's Ferry below Glen Canyon Dam, the lowest flow of the decade. Even after this year's above-average precipitation, Lake Powell and Lake Mead combined are at 57 percent capacity.

A 2007 U.S. Geological Survey report found that, by 2050, rising temperatures in the Southwest could rival those of the nation's fabled droughts, including the Dust Bowl of the 1930s. Hotter weather is expected to reduce Colorado River runoff by at least 30 percent during the 21st century.

If the USGS is correct, and if this century's trend persists, average annual flow in the Colorado could fall to 8.2 million acre-feet per year.

Imagine that. The Law of the River requires 9 million acre-feet to pass Lee's Ferry on the way to the Lower Basin and Mexico. Under a strict interpretation of the law, the Upper Basin could be left with nothing.

You can read the rest of the article. Even Peter Gleick and Pat Mulroy would not be able to make things right.

But at least Las Vegas is using less water these days.

Meanwhile, elsewhere in the CRB...I was in the Phoenix area (Tempe, actually) several weeks ago with some colleagues. At Arizona State University's remarkable Decision Theater we got a taste of high-tech decision-making. It is part of the Global Institute of Sustainability (GIOS).

We heard some interesting things, but one in particular made an impression on me. One of the folks told us that in the Greater Phoenix area, if you go to a local politician/water manager with a predictive model that shows a future with less precipitation, you're out of luck. They're not even thinking about that possibility. Heads in the sand, or what?

I think I am getting close to finding someone who is "thinking about the unthinkable" regarding Southwest water and depopulation, particularly in the Colorado River Basin.

"Las Vegas is Everyman's cut-rate Babylon.  Not far away there is, or was, a roadside lunch counter and over it a sign proclaiming in three words that a Roman emperor's orgy is now a democratic institution - 'Topless Pizza Lunch'."  ~Alistair Cooke

"Do you know what we call tourists in Las Vegas? We call them 'marks'." - desk clerk, San Remo Hotel, Las Vegas, NV

CRS Insight Report: 'FEMA Pre-Disaster Mitigation: The Building Resilient Infrastructure and Communities (BRIC) Program'

Diane P. Horn wrote this updated (28 December 2020) CRS Insight report: 'FEMA Pre-Disaster Mitigation: The Building Resilient Infrastructure and Communities (BRIC) Program'.

One of the features of the Insight report series is that there are hot links for those who wish more information. If you can't access the links in the PDF version (below), then click on the title (above) to access the online version. 

Download CRS_Insight_FEMA_BRIC_28Dec2020

I have pasted in the first section, then the final section.

Changes to Pre-Diasater Mitigation Funding
The federal government has historically provided resources to assist in recovery after a disaster and reduce future risk. The Disaster Recovery Reform Act of 2018 (DRRA, Division D of P.L. 115-254) introduced an increased emphasis on pre-disaster mitigation, authorizing a new source of funding for pre-disaster mitigation called the National Public Infrastructure Pre-Disaster Mitigation (PDM) Fund. For each major disaster declaration, the President may set aside from the Disaster Relief Fund (DRF) an amount equal to 6% of the estimated aggregate amount of funding awarded under seven sections of the Stafford Act.

There is potential for significantly increased funding following a year with many big disasters, but funding could also be less in a year with few disasters. FEMA anticipates that the new fund will receive $300-$500 million per year on average. As of November 30, 2020, there was $962 million available in the 6% set-aside from the DRF. This includes a $500 million set-aside associated with COVID-19; FEMA estimates up to $3.7 billion for BRIC as a result of the COVID-19 major disaster declarations.

Cutting to the chase...

Considerations for Congress 
The majority of funding for hazard mitigation comes from the Federal Emergency Management Agency (FEMA), which administers three Hazard Mitigation Assistance (HMA) programs: the Hazard Mitigation Grant Program (HMGP), the Flood Mitigation Assistance (FMA) Grant Program, and the Pre-Disaster Mitigation (PDM) Grant Program. These three programs are described in CRS Insight IN11187, FEMA Hazard Mitigation Assistance. Over the years, post-disaster mitigation has received significantly more funding than pre-disaster mitigation. For example, in FY2017 FEMA obligated $5.4 billion for HMGP. In contrast, Congress appropriated $90 million to PDM. According to GAO, annual HMGP grants have reached $2.9 billion while PDM and FMA have never exceeded $300 million. Despite the substantial increase in overall funding for pre-disaster mitigation that the 6% BRIC set-aside represents, the post-disaster mitigation approach embodied in HMGP still receives more resources. 

States are no longer guaranteed a minimum amount as they were under PDM. However, according to FEMA, projects submitted in category (1) should be funded up to the $600,000 maximum if they submit eligible applications up to this limit. The $50 million cap for an individual mitigation project in BRIC also represents a significant increase; the largest amount available for PDM activities in FY2019 was $10 million. Since the PDM program was established in 2000, two projects have been awarded more than $4 million, and 280 projects (approximately 7%) have been awarded more than $1 million. Some stakeholders have expressed concern that smaller or more traditional projects may be less likely to obtain support in BRIC, and that small, impoverished, or rural communities may not have the capacity to apply for and administer the larger amounts which could be funded by BRIC. 

FEMA has not yet decided whether they will use all of the 6% set-aside funds each year or keep some back for years with fewer disasters and thus less funding. 

Enjoy!

"As we approach the new year, we wanted to remind faculty and staff that, when it comes to academic administration, it can always get worse. So make it a New Year's resolution to appreciate your ass deans!" - @ass_deans

CRS InFocus Report: 'Water Resources Development Act of 2020'

From Nicole T. Carter and Anna E. Normand - an updated (29 December 2020) CRS InFocus report: Water Resources Development Act of 2020. This two-pager provides a great overview of the WRDA 2020, just signed into law on 27 December 2020.

Download CRS_InFocus_Report_WRDA_2020_29Dec2020

Overview
Congress commonly titles omnibus legislation that authorizes U.S. Army Corps of Engineers (USACE) civil works activities as a Water Resources Development Act (WRDA). Since WRDA 1986, Congress often has considered a WRDA biennially. Drivers for enactment typically include nonfederaland congressional interest in new studies and construction projects and adjustments to existing projects, programmatic authorities, and policies. Congress passed the Water Resources Development Act of 2020 (WRDA 2020) as Division AA of H.R. 133, an omnibus appropriations and authorization act, signed by President Trump on December 27, 2020. The116th Congress had considered other versions of a USACE authorization bill. For example, the House passed S.1811 in early December 2020 and H.R. 7575 in July 2020. The Senate Committee on Environment and Public Works reported S. 3591 in May 2020.

Like most previously enacted WRDAs, WRDA 2020 not only authorized USACE studies and projects but also refined congressional policy direction for USACE and adjusted existing USACE civil works authorities. In addition to USACE-related provisions, a limited number of WRDA 2020 provisions are associated primarily with other agencies (e.g., §§507, 508, 510).

Cutting to the chase...

Processes for Identifying Studies and Projects
Adherence to earmark moratoriums has altered how Congress identifies activities for inclusion in a WRDA. In Section 7001 of P.L. 113-121 (33 U.S.C. §2282d), Congress established an annual process for identifying proposals for USACE studies and projects that are related to the agency’s missions and authorities that require specific congressional authorization. Congress has used the annual Section 7001 reports to identify activities for authorization in WRDAs.

USACE’s civil works activities historically have focused on three primary purposes: improving navigation, reducing flood risk, and restoring aquatic ecosystems. Many USACE projects are multipurpose—that is, they may provide water supply storage, recreation, and hydropower, among other benefits, in addition to one or more of the three primary purposes. WRDA2020(§127) directs that the Section7001 reports are to include proposals submitted for projects with municipal or agricultural water supply purposes that are consistent with the agency’s mission and authorities.

WRDA Implementation and Oversight
Congress establishes the broad structure for how USACE is to perform its water resource activities. After enactment of a WRDA, USACE often develops guidance that describes how the agency plans to implement various provisions, and Congress often engages in oversight.

Enjoy!

"Someone who comes more than 500 miles and uses colored transparencies." - Definition of an expert, c. late 1960s - early 1970s

Paper: 'Diverse Paradigms of Residential Development Inform Water Use and Drought-related Conservation Behavior'

I just caught this recent (18 November 2020) open-access paper by Kimberly J. Quesnel, Saahil Agrawal and Newsha K Ajami: 'Diverse paradigms of residential development inform water use and drought-related conservation behavior', Environmental Research Letters 15(12) (2020) 124009.

Read the article online by clicking here. The links below may not take you to the reference but to the original Quesnel et al. paper.

Download Quesnel_2020_Environ._Res._Lett._15_124009

Download ERL_15_12_124009_suppdata

Abstract
Widespread urbanization has led to diverse patterns of residential development, which are linked to different resource consumption patterns, including water demand. Classifying neighborhoods based on urban form and sociodemographic features can provide an avenue for understanding community water use behaviors associated with housing alternatives and different residential populations. In this study, we leveraged built environment data from the online real estate aggregator Zillow to develop neighborhood typologies and community clusters via a sequence of unsupervised learning methods. Five distinct clusters, spatially segregated despite no geospatial inputs, were associated with unique single-family residential water use and conservation patterns and trends. The two highest-income clusters had divergent behavior, especially during and after a historic drought, thus unraveling conventional income–water use and income–water conservation relationships. These clustering results highlight evolving water use regimes as traditional patterns of development are replaced with compact, water-efficient urban form. Defining communities based on built environment and sociodemographic characteristics, instead of sociodemographic features alone, led to 3% to 30% improvements in cluster water use and conservation cohesion. These analyses demonstrate the importance of smart development across rapidly urbanizing areas in water-scarce regions across the globe.

Introduction
Today, 55% of the world's population lives in urban areas with the percentage expected to grow to 68% by 2050 (United Nations Department of Economic and Social Affairs Population Division 2019). As residents move away from rural areas and into cities, suburbs, and towns, many different patterns of residential development and urban form are emerging, in turn affecting urban system sustainability (Jabareen 2006, Pandit et al 2017, Pickett and Zhou 2015). Variations in population density, housing structures, and neighborhood configurations are linked to different energy use patterns, transportation behaviors, and public health outcomes (Berrigan and Troiano 2002, Ewing and Rong 2008, Güneralp et al 2017, Stokes and Seto 2019). Housing features including urban versus suburban communities (Breyer and Chang 2014), infill development (Sanchez et al 2020), changing building and landscaping codes (Brelsford and Abbott 2017, Garcia and Islam 2019), and nontraditional housing arrangements (Barnett et al 2019) can also lead to heterogeneous residential water use behavior, which has direct implications for water resources management.

Simultaneously, sociodemographic characteristics like income and education levels often explain variations in residential water use (Schleich and Hillenbrand 2009, Shandas and Parandvash 2010, House-Peters and Chang 2011, Brelsford and Abbott 2017, Quesnel and Ajami 2017, Fan et al 2017). Together, built environment and social features provide the building blocks for defining neighborhoods and communities for urban water demand assessment and planning (Jackson-Smith et al 2016, Stoker et al 2019), which in turn dictate water supply and infrastructure investment decisions at city to neighborhood scales (House-Peters and Chang 2011, Stoker and Rothfeder 2014, Gurung et al 2016). These characteristics are also critical for understanding water conservation behavior during drought (Fielding et al 2012, Polebitski and Palmer 2013, Mini et al 2015), when strategic resource management is particularly critical.

Grouping residential customers for water resources planning and management requires linking bottom–up, household-level data about the built environment with top–down Census block-group or tract scale features. Built environment and social data can also be acquired through customer surveys (Randolph and Troy 2008, Harlan et al 2009, Willis et al 2013, Hannibal et al 2018), but these can be expensive, time-intensive, and limited in scope. Some researchers have successfully accessed assessor records on homes and parcels (for example: Chang et al 2017, Brelsford and Abbott 2017), but this data is generally challenging to obtain in bulk, digitized formats and must be acquired on a city-by-city or county-by-county basis. Around the US, a few agencies have moved to publicly available digital records like New York's Primary Land Use Tax Lot Output (PLUTO) database, which can be used for building-level water demand studies (Kontokosta and Jain 2015), although these are not yet common.

New websites like Zillow, Redfin, or Trulia that aggregate and digitize records from multiple sources, including public agencies, offer the possibility to overcome this historic obstacle, but these sources have yet to be leveraged as a tool for analyzing urban water use. Together with Census information, this housing data can be used as an alternative to traditional sources to develop a holistic depiction of communities within a city, a spatial-scale which provides the granularity of within-city information while being more practical than customer-level analyses. This research aims to demonstrate the value of combining data on single-family residential housing features and urban form from Zillow with Census data to identify residential community groupings. In turn, these classifications can help water resource decision-makers better understand their customers' water use behavior, design optimal conservation policies, and plan for future resources needs and allocation.

We performed our analysis within a single utility—exploring high-resolution data within a small area to gain insights into behavior not possible at more aggregated scales while discovering information that can be applied in a broader context. Our study area, the City of Redwood City (Redwood City) is situated on the San Francisco Bay peninsula in California and represents a microcosm of diversity—in 2017, block-group level median household income within the service area ranged from less than $40 000 (including several block-groups classified as Disadvantaged Communities) to over $220 000. The San Francisco Bay Area represents a region with varied and evolving water supply and demand regimes, making it a particularly valuable place to study urban water with lessons for other growing, semi-arid and arid regions across the Western U.S. and the world (Gonzales and Ajami 2017b). In our study, we focused specifically on single-family residential water use, which accounts for 65% of California's urban water use (California Department of Water Resources 2016) and about half of Redwood City's potable use (City of Redwood City 2015). Redwood City demand is seasonal, with higher use in the summer due to landscape irrigation.

Our research takes place over a 10-year period from 2008–2017 which included two     historic droughts and an economic recession. In particular, the 2012–2016 drought was one of the most severe in California's history (U.S. Geological Survey: California Water Science Center 2018). The drought was not only exceptional hydrologically, but also in terms of state and local political actions, public awareness, and news media coverage that led to high drought saliency and has been associated with high conservation rates (Quesnel and Ajami 2017, Gonzales and Ajami 2017a, Bolorinos et al 2020). This historic drought provides an important setting for examining not only the drivers of water conservation, but also rebound once mandatory restrictions were lifted and the drought was declared over (Gonzales and Ajami 2017a, Bolorinos et al 2020). Evaluating water conservation during the 2012–2016 drought, an extreme event more likely to occur in the future, provides an opportunity to evaluate changing residential water use behavior across customers under escalating climatic and policy regimes.

Cutting to the chase...

Discussion and conclusion
This research demonstrates the coupled role of urban form and sociodemographic characteristics in water use and drought-related conservation behavior. A crucial finding of this study is the importance of the built environment when classifying urban water customers and creating residential neighborhood typologies useful for water use and conservation analyses and developing demand management strategies. Traditionally, many researchers have stratified customers by income, finding that affluence is associated with high water use, high levels of drought-related conservation, and subsequently high conservation backslide post-drought. These water use characteristics are typically linked to more wealthy customers having bigger lots and therefore using more water outdoors. However, this study proves that income does not always correlate to high water use, and that affluent residents choosing to live in dense, new developments have very different water use patterns and water use behavior.

We bypassed previous data constraints faced by researchers, utilities, municipalities and other public agencies trying to better understand how built environment factors are linked to water use by utilizing data from an online real estate aggregator. By obtaining customer-level information from the Zillow ZTRAX database, this research for the first time demonstrates the possibility for this kind of platform to serve as a new tool for incorporating housing features into water use analyses. City and county assessors are legally required to fulfill public record requests and provide data in response to inquiries, but acquiring these individual datasets for comparative regional, state, or national assessments can be prohibitive. Thus, using aggregated data generated by Zillow and similar websites can provide a gateway for widespread analyses, for example opening the door for multi-city or even multi-state studies. These new websites offer a way to access built environment data uniformly in one place instead of filing separate records request for each service area of interest. While this research presents an alternative to traditional methods for obtaining information about the built environment, water use data remains sparse and challenging to acquire (Chini and Stillwell 2016, Josset et al 2019).

As this is the first research to use Zillow in water demand research, there are a host of avenues for future research. For example, our study was set within one utility, but the potential for Zillow truly lies in its ability to cross administrative borders. For example, where cross-city and multi-city comparisons in different counties previously required obtaining data from each individual jurisdiction, Zillow or other online aggregators store this data in one central location. Having one central database also provides the benefit of data consistency.

Additionally, here we focused primarily on neighborhood clustering to inform residential water use modeling at the monthly scale, but future studies could explore how emerging databases, online platforms, and data aggregators with high spatial and/or temporal resolution can be coupled with higher temporal resolution water use data from smart meters to better understand and predict water use and conservation. These insights could then be used to develop short-term and long-term demand management strategies. Another avenue for future research would be to investigate how different emerging urban form paradigms including infill development, peri-urban, and suburban designs shift both short- and long-term water use behavior. Land managers and water managers often do not coordinate or even talk to each other (Gober et al 2013), but with these new developments and unprecedented urbanization, there is increasing pressure for integrated planning and management.

This research lays the framework for future big data-driven urban water research and provides evidence for the implications evolving urban form on water use. Our results also point out future paths of more water-efficient urban development. Cities all over the world are expanding at rapid rates, and there are many different ways for them to develop. Here, we showed that dense housing patterns and new houses, regardless of the size, can result in lower water use than traditional sprawl. However, these low water use communities also have lower conservation rates and sometimes faster post-drought water demand rebound, and actions must be taken to account for this reduced water system flexibility. City planners and water managers must work together to develop cities of the future that house an increasingly large portion of the population and meet the wide-range of sustainability-oriented goals critical to addressing 21st century urban challenges.

Good stuff!

Enjoy!

"You can't teach an old dogma new tricks." - Dorothy Parker (quoted in @TheMVTimes via @TheWeek)