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There have been droughts throughout history as Paleoclimatology tree ring investigations have discovered. In the 1200s in the Southwest United States in Anasazi territory, the drought lasted for multiple decades because of extremely low precipitation, according to Richard Heim, a meteorologist with the National Climatic Data Center (NCDC) in North Carolina, one of the divisions of the National Oceanic and Atmospheric Administration (NOAA).

In the 1930s, the drought in the Midwest lasted a decade. Serious drought conditions since then have peaked and gone away in the 1950s, the 1970s, and the 1980s. Since 1999, however, drought conditions have expanded, peaked, contracted, and peaked again. It is a drought that doesn’t want to go away—a balloon that expands and contracts like no other time—as Heim explains. Since 1980, major droughts and heat waves within the US alone have resulted in costs exceeding $100 billion, easily becoming one of the most costly weather-related disasters on the continent, according to a 2000 NCDC technical report penned by Neal Lott and Tom Ross.

Droughts in the US can be tracked for the past 100 years through the Palmer Drought Index. It is a soil moisture algorithm calibrated for relatively homogeneous regions and is used by many government agencies and states to trigger drought relief programs. At the end of January, the index calculated 24% of the US was in moderate to extreme drought.

With the development of geographic information system software and satellite imagery produced by the 16 meteorological satellites now orbiting the Earth, many different products and services have emerged, says Heim. NOAA’s National Environmental Satellite Data Information Service, NCDC’s parent agency, acquires and manages the nation’s operational environmental satellites, provides data and information services, and conducts related research.

The US Drought Monitor is a national publication prepared weekly as a collaboration between NOAA, the US Department of Agriculture, and the National Drought Mitigation Center (NDMC). It provides a synthesis of multiple indices and impacts that represent a consensus of federal and academic scientists. Heim is one of the regular authors. He says the Monitor is a bit more accurate, but given that it was started in 1999, it lacks the historical perspective of the Palmer Index. The Monitor reports that 21% of the continental US is in an exceptional drought.

Drivers of Drought
There are four compelling drivers of drought, says Heim: climate or the amount of sun we get; topography, i.e. the arrangement of continents and oceans; ocean temperatures; and, finally, the composition of the Earth’s atmosphere, which we are affecting with the release of carbon dioxide. According to Heim, humans are influencing the climate for the first time to a greater and greater extent.

Heim says global climate models are predicting that with overall temperatures increasing, the hydrological cycle is intensifying: Water demand should go up, but with warmth there is a greater capacity to hold water in the air, leading to more rain. We can expect more short interval droughts, more and heavier rains that cannot soak into the ground, and more floods that rivers cannot control.

Heim describes four kinds of drought: meteorological; hydrological in which the water table goes down; the agricultural drought when crops that need water at specific times don’t get it in dry land farming; and socioeconomic drought.

In socioeconomic droughts, people need water, factories need water for processing, power plants need water for cooling, and the demand keeps increasing. Pretty soon, there is not enough water to meet the demand. As the population continues to increase, Heim predicts this type of drought will become a real problem. It is beginning to impact the South. “People need to focus on being more efficient water managers and learn how to get more water into the system,” says Heim. “Drought needs to be an overall part of managing water more efficiently.”

“We’ve been around for thousands of years, but only in the last 300 years have we started affecting the global climate,” concludes Heim. “We need to be responsible players in the earth’s climate.”

What Is GIS?
In 1854, John Snow used points on a map of London to represent the locations of individual cases of cholera during the outbreak there, which led to the source of the disease—a contaminated water pump which Snow quickly dismantled. This was the first recorded use of cartographic methods to analyze clusters of geographically dependent phenomena.

The world’s first truly operational GIS was developed in 1962 in Ottawa, Ontario, Canada by Dr. Roger Tomlinson of the federal Department of Forestry and Rural Development. Features of the Canada Geographic Information System were successfully incorporated in GIS software developed by the early 1980s by M&S Computing (later Intergraph), ESRI, and Computer Aided Resource Information System (CARIS). These developments combined the first-generation approach to separation of spatial and attribute information with a second-generation approach to organizing attribute data into database structures.

Meanwhile, two parallel public domain systems began development in the late 1970s.  MOSS, the Map Overlay and Statistical System project, started in 1977 in Fort Collins, CO, under the auspices of the Western Energy and Land Use Team and the US Fish and Wildlife Service. In 1982, the US Army Corps of Engineering Research Laboratory in Champaign, IL developed GIS for use by the US military.

Photo: Green World Solutions A map type plot of bad design, with red meaning too little water, blue meaning too much water, and green meaning an average amount of water

Photo: Green World Solutions A map type plot of good design, with green and blue, no red

The Private Sector Innovates
Companies have sprung up or reoriented their business to create and market GIS data products to state and local agencies, municipalities, and private companies for all kinds of uses, such as scientific investigations, archaeology, environmental impact assessment, criminology, and geographic history. Water management, long-range planning, and weather tracking is high on the list.

ESRI, headquartered in Redlands, CA, is acknowledged by many to be the world leader in GIS technology. It was founded in 1969 as a consulting firm that specialized in land use analysis projects. By the 1980s, it was devoting its resources to developing a core set of application tools that could be applied in a computer environment to create a GIS technology.

Steve Kopp, program manager for geoprocessing and analysis at ESRI, says the company has over 90% market share in water resources. Its water community customers have a pretty broad base, spanning everything from federal agencies doing broad scale resource management to water districts, basin, and aqueduct managers, people who do water distribution, and civil engineers doing flood modeling. Furthermore, there has been a strong integration between ESRI’s software and the Army Corps of Engineers’ hydrologic modeling software as well as commercial water modeling software.

NOAA and the National Weather Service, as well as the national meteorological agencies of the United Kingdom and Australia use ESRI GIS software, in conjunction with numerical predication models, to understand the spatial and temporal distribution of precipitation, and, therefore, the potential for drought or floods. 

For example, they might be interested in knowing how much rain would fall within a watershed over a period of time, given the shape of the channel, and the chance that flooding might occur and its extent, Kopp explains. The Federal Energy Management Administration has a project called HAZUS that uses flood and other hazard models set on top of ESRI software for natural disaster damage assessment.

GreenWorld Solutions, in Riverside, CA, was established two years ago to promote GIS technology. It created a product called “Green World Solutions GPS Audit Technology.” The company uses it to assist developers and water districts in complying with California law AB 1881, which went into effect January 1, 2009. This law updated the state’s “water efficient landscape ordinance” and requires 71% efficiency for landscape irrigation designs of areas 5,000 square feet or larger. Subsequent regulations have mandated high-efficiency requirements for landscape irrigation equipment including irrigation controllers, moisture sensors, emission devices, and valves. The new law also requires audits every five years.

Geza Kisch, a consultant with GreenWorld explained that water districts typically ask his company to work with private developers to comply with the new law. While the private water users pay them, the water district typically reimburses the users as part of an incentive program.

Kisch says when landscaping is being designed for a new park or school site, for example, the design submitted to the city has to guarantee that the performance of the physical irrigation system will match what the design promises. Once the landscaping is installed, the water district will monitor the water usage. This process will reduce water usage 50% on average, Kisch says, depending on specific locations and consumption.

Furthermore, Kisch explains, information on evapotranspiration (ET) will be free and provided by the state of California. Every controller can be adjusted on a daily basis by downloading the latest ET data. 

Before GIS and satellite imagery were available, the correct distribution of water coming from sprinkler heads was hard to determine and led to wasted water. Electronic water audits were inaccurate and unrepeatable, because they sampled only certain areas, offering a very limited view of water distribution. “The two largest causes of water waste have been between design and installation, and in the operation,” he says. Water usage can be two to three times more than the design intended.

Kisch explains that now, using his company’s GIS software, every sprinkler head can be located accurately. It eliminates the gap between design and installation and operation. All kinds of data, such as rainfall, soil infiltration, and content, are digitized and fed into the software, even aerial photographs, to create a three dimensional model of the area to be irrigated. Once controllers equipped to handle these data are installed the design model is downloaded into them. The controllers are then driven by the software-modeled climate data to turn the sprinklers on and off accordingly. “If you don’t connect spatial distribution to a controller, the controller is useless,” he says.

Smart controllers that can handle GIS modeling data have been coming on the market in the last two years, Kisch says. There are now perhaps three models that qualify. Furthermore, these controllers can be connected to a Web site that monitors all sites on a daily basis. Managers then can see which sites are under the water budget and which are over. The Metropolitan Water District in southern California already has a $15-million rebate program to replace old, non-compliant controllers free of charge.

National Agencies 
At NCDC, where Heim works, weather data from across the country and the world is archived and compared with historical data to put our current climate into perspective.  NCDC’s motto is “Protecting the Past, Revealing the Future.” It produces numerous climate publications and responds to data requests from all over the world. NCDC also supports a three-tier national climate services support program in partnership with the Regional Climate Centers and State Climatologists.

Heim says several different offices create satellite products. For example, VegDRI, the Vegetation Drought Response Index, which Heim describes as “a wonderful little product,” uses satellite observations coordinated with actual weather conditions, topography, and soil types to monitor and assess vegetation health.

The NDMC was established in 1995 to help people and institutions develop and implement measures to reduce societal vulnerability to drought. It is headquartered at the University of Nebraska–Lincoln and is independent of state or federal government. However, it is a major collaborator with NOAA’s NCDC.

Mark Svoboda is a climatologist at NDMC who specializes in remote sensing and GIS technology. “Our overall mission is to plan for risk vulnerability to drought,” he says.  “We will never have a dense enough coverage of...the whole US using ground data. We have to use other remote sensing tools to gain a full snapshot of what is going on [throughout the country].”

Overlaying satellite imagery with what he calls “ground truth,” i.e. weather station data, soil types, and such, gives planners a better feeling with what modeling is telling them. “The more tools at our disposal, the more knowledge we will have,” says Svoboda.

Svoboda says that adoption of these tools by water districts will likely vary depending on the agency. A drought plan is a comprehensive risk assessment of all water uses, he explains. But creating a baseline—determining what is normal water use—is apparently a problem. “We need a lot more people and data to create baselines,” he says. “The biggest challenge is turning over to operational control the tools NDMC and NCDC have created—how to make them mainstream,” he concludes. “The key is early warning through these sorts of tools. It is a good way to keep an eye on drought conditions.”

What Are Water Districts Using?
Sean Cronin, Water Resources Manager for Greeley, CO, says his department uses GIS software and satellite imagery for a variety of tasks. Ground truth is not useful when crafting 50-year time horizons, he says. The industry is getting away from what he described as lines and polygon file information, and going to high-resolution satellite imagery. But, he adds, GIS is just one tool in the toolbox. 

Water rights in Colorado are controlled by the state constitution and every drop of water is claimed by someone, Cronin says. For example, when people file water use permits, “we use GIS to identify how that water use will affect Greeley.” Satellite imagery might be called on to identify areas with water supplies in high growth areas where new pipes may need to be laid, he adds.

Brian Sullivan, head of the GIS group in Greeley’s Information Technology department described how GIS software and integrated aerial photography are used to maintain the city’s water assets, including the locations of pipes, meters, manhole covers, and sprinklers, to name a few items. The software can tie into utility billing systems, and since each meter has its own number, the system can watch over each residence or business’s water consumption.

Users’ consumption data are integrated into citywide consumption reports where customers that don’t have efficient water usage can be identified. “Most likely, they don’t have water efficient toilets,” says Sullivan. Instead of being fined the first time, violators are usually allowed to become part of the toilet replacement program. 

Sullivan says his department does not use satellite imagery. Instead, four-band aerial photography reveals irrigated areas where plants are growing, and this information is used in the water budget program. The department buys the GIS software from ESRI that upgrades it every quarter under a management agreement between the city and the company.

The Southern Nevada Water Authority (SNWA) is a cooperative agency formed in 1991 to address Southern Nevada’s water needs on a regional basis. It is a descendent of the Southern Nevada Water System developed in the 1950s to provide water supplies for southern Nevada’s burgeoning growth. It provides wholesale water to seven water agencies, including two serving Las Vegas, and another in North Las Vegas.

SNWA operates two water treatment facilities that divert raw Colorado River water from Lake Mead and delivers potable water to its member agencies. Its responsibilities also include managing regional water resources and conservation programs as well as long-term water resource planning.

SNWA has created aggressive landscaping watering restrictions accompanied by water-waste fees for transgressors. It also has turf restrictions, golf course water budgets, and heightened water-waste enforcement. All this because the Colorado water system, which is the source of water for Southern Nevada, including Las Vegas, is facing the worst drought on record. Lake Mead’s water level has dropped approximately 100 feet since January 2000. 

Thanks to community compliance with conservation measures, the Las Vegas Valley is continuing a trend of declining water use. Southern Nevada’s annual water consumption decreased by nearly 21 billion gallons between 2002 and 2008, despite a population increase of 400,000 during that span.

The SNWA Board of Directors has set a conservation goal of 199 gallons per capita per day (GPCD) by 2035. The community used 254 GPCD in 2008. SNWA and its member agencies have chosen to permanently implement the drought response measures as part of the overall conservation effort based on community desires to build up long-term water resources.

Big Brother Watches Over Thirsty Lawns
Doug Bennett, SNWA conservation manager, says GIS software, satellite imagery, and aerial photography are used extensively in management and conservation of its current water resources as well as hydrologic assessments of potential water resources.

Once a year, SNWA arranges for a fly-over of its service territory to monitor changes in urban vegetation, where 70% of its water is used, Bennett says. Aerial high-resolution 6-inch-per-pixel images are taken, as well as multi-spectral images. These images show what landscaping people have and how it has changed in the past year. “In 2003, we got very aggressive and now forbid turf (lawn grass) in commercial landscapes, and we limit residential use,” says Bennett.

Monitoring landscape watering is elaborate and dependent on GIS and aerial photography. SNWA uses multi-spectral imagery with full natural colors to identify parcels where vegetation grows. Staff has to accurately measure lawn areas, but this can be difficult since lawns are never exact rectangles. Instead, they take key reference measurements on the ground and transfer known ground locators, such as corners of the lawn, using ArcView, a computer-mapping tool, to overlay the information on the aerial map. By moving the cursor over the parcel, the square footage can be identified. A polygon is then drawn of the lawn on the aerial map.

“We can send the owner a picture with detailed polygons. It gives us a very high standard of credibility,” says Bennett.

Linking parcel numbers identified above to utility bills can identify water waster owners. Mailings are then targeted to those homeowners telling them about the WaterSmart landscape programs. Rebates are available to convert lawns to drought-tolerant landscaping at $1.50 for every square foot of grass replaced up to 5,000 square feet. Beyond that, homeowners can get $1 per square foot for a maximum of $300,000. Mailing targeted messages is much more effective than doing large direct mailings to all users, says Bennett.

The Eastern Municipal Water District (EMWD), headquartered in Perris in Riverside County, CA, provides freshwater, wastewater service and recycled water to a 556–square mile area in the Moreno Valley and southward, about a two-hour drive east of Los Angeles. EMWD supplements water to eight local water agencies and municipalities that have their own water departments. It also operates four water reclamation facilities.

Engineers rely heavily on land use and growth projections in a region that saw major development in 1990 rise to 21%. By 1996, development had dropped to 3.5% and rose again to 15% by 2003. EMWD needed to accurately predict domestic and recycled water demands and sewage flows for a complex system, but discovered deficiencies in its distribution system and its available water supply.

Before the advent of GIS, the staff colored map subareas by hand, based on general plans from all involved cities, counties, and other jurisdictional agencies to create a picture of their system. Once GIS technology arrived and ESRI created its core product software, Arc/Info, in the early 1990s, EMWD acquired these tools to organize, consolidate and analyze all the information. Later, it acquired H2OMAP from MWH Soft Inc., in Pasadena, CA, which read and shared native Arc/Info data and automatically constructed, skeletonized, and analyzed a network model.

This combination allowed EMWD to maintain a single detailed geospatial hydraulic model of its system that is easily updated and displayed. By 2003, EMWD was able to run the configuration on workstations and desktops using ArcView, a lighter, user-friendly version of Arc/Info.

Creating a new Water Facilities Master Plan with this capability meant no more hand coloring of maps, but it was still an ambitious job for the staff. Existing water system facilities, historic water use, and projected future demands had to be added to the GIS-based model. 

The master plan included an evaluation of the existing system, recommended new facilities, updated the phased water system improvement program, identified a strategic plan for future sources of water supply, and determined the total capital improvement costs proposed by the new master plan—over one-half billion dollars.

The eventual product was a four-by-five-foot map created from the Water Facilities Master Plan by EWMD’s Charles Crider. He loaded the H2OMAP data files into ArcView, color-coded them, and overlaid them onto a highly detailed set of more than 300 aerial photographs that were also pulled from the master plan model. The resulting map depicts the complex network of pipelines including nearly 100 storage reservoirs and as many pump stations. 

Since 2003, the software has been upgraded to InfoWater, another MWH Soft product, which integrates more easily and runs on top of ArcMap. The Water Facilities Master Plan is also being updated, using new aerial photography.