GIS Maps, Computerized Sprinklers Help Munis During Drought

Historic droughts in California, Georgia and elsewhere prompt cities to turn to IT -- like GIS maps -- for conservation help.

by / February 9, 2009 0

As some states, like Georgia and California, cope with historic droughts, they're turning to technology to aid water conservation - not only for drought recovery, but also to prepare for a future of smaller water supplies.

Climatologists say climate change will worsen dry spells - so the problem isn't likely going away.

As weather patterns change, governments are creating initiatives that save water, time and money. These improvements include automatic water meter readers, satellite-based evapotranspiration monitoring and electronically controlled watering systems.

 

Smart Irrigation

Healdsburg, Calif., was seeking a more efficient way to water its athletic fields and instead found a solution that overhauled its water conservation initiatives. According to David Mickaelian, the city's community services director, many of Healdsburg's fields used manual water controllers. If a city worker needed to change the watering schedule, he or she had to visit the field to make the updates. Park Superintendent Matthew Thompson told Mickaelian about WeatherTRAK, a climatologically controlled irrigation system.

WeatherTRAK is a remotely managed sprinkler controller that automatically adjusts water schedules based on a landscape's needs - such as how much water specific plants living there require - and the local weather conditions. Mickaelian said the system has a one-day lag, using the previous day's weather information to modify watering times.

"It has a satellite; it tracks the weather patterns," he said. "So what it does, it really tracks the weather for us. On really hot days, it automatically adjusts to irrigate based on the temperature readings from the previous day."

The city installed the technology in 2007 in selected parks to ensure the system worked properly. After comparing the park's water usage between 2006 and 2007, the city calculated water savings in the range of 5.5 percent to 18 percent. "We started to realize this is more than we're looking for as far as the payback because now we're starting to see significant savings, and that correlates with reduced water use," he said.

The system is enabling the city to update its entire water system. By tracking water metrics Healdsburg is finding that some meters are tied together that shouldn't be - such as athletic fields' irrigation systems that are connected to bathrooms. Mickaelian said when the metric doesn't match the expected savings it prompts them to investigate the issue. The technology also reports water leaks in real time, allowing officials to fix problems immediately and reduce the amount of wasted water. Another bonus is that man-hours have decreased because the systems can be remotely controlled.

Healdsburg's water use was down 11 percent in 2007 through a combination of city-led efforts and citizens who voluntarily reduced their water consumption. The city plans to upgrade all athletic fields, parks and pools with the irrigation system technology within the next two years for less than $40,000.

"This WeatherTRAK system, it kind of goes into our toolbox if you will, so it allows us to be a leader in the community saying, 'We're practicing what we preach,'" Mickaelian said.

 

Extreme Drought

In fall 2007, Gov. Sonny Perdue declared that most of northern Georgia, including Atlanta, was in a Level 4 drought and he required all water utilities to cut back production by 10 percent. Atlanta had already enacted outdoor watering restrictions, which reduced water use by 14 percent. "We had already taken care of all the low-hanging fruit," said Melinda Langston, director of water conservation for Atlanta's Department of Watershed Management, "and we really had to go to some drastic measures at that point."

According to the National Drought Mitigation Center, Level 4 is the most severe drought classification. Atlanta is working on many initiatives to mitigate the drought's impacts.

As part of the city's $3.9 billion Clean Water Atlanta infrastructure improvement program, an initiative was launched in

December 2006 to convert all water users - commercial and residential - to an automated meter-reading system. The change will reduce meter reading, customer service and operating expenses, while ensuring the accuracy of customer usage numbers. Langston said this switch, which is halfway complete, is the largest contributing factor to the city's success in moving toward water efficiency. Officials track water usage by monthly readings or at any time by using a radio system and driving by locations to pick up readings.

Langston said Atlanta also is encouraging citizens to purchase household water conservation aids, such as the HydroClean Fill Valve that cuts toilet water consumption as much as 33 percent. The city invested $1 million in a residential toilet rebate program that encourages residents to replace toilets that use 1.6 gallons of water or more per flush.

"The bottom line for us is we really need to be in a water conserving mode from now on," she said. "And this has been a good opportunity to teach people how to do it."

The city-owned Hartsfield-Jackson Atlanta International Airport is upgrading its 725 toilets, 338 urinals and 601 sinks to low flow, according to Al Snedeker, the airport's public relations manager. By switching toilets from 1.6 gallons per flush to 1.28 gallons per flush, the airport estimates it will save 44 million gallons per year.

The airport uses almost 1 million gallons of water per day and would like to reduce consumption by 15 percent in 2009. The airport's maintenance division installed three rain barrels each with a maximum capacity of 2,500 gallons. The barrels collect water that would otherwise be unused. Now it's used for washing maintenance vehicles and watering the grounds, Snedeker said.

 

Mapping Water Use

Idaho is using remote sensing and GIS to be resourceful with water. Instead of devising measures for drought recovery, officials are working toward being sustainable and preparing for the future.

Tony Morse, GIS manager of Idaho's Department of Water Resources, said the state uses a satellite-based evapotranspiration (ET) tracking model. ET is the water that's evaporated from soil or transpired from vegetation, and it represents the amount of water loss from a watershed. Tracking ET lets state officials see how much water is used by irrigated agriculture, like farms. This is an important measurement because irrigated agriculture accounts for more than 95 percent of Idaho's water. Morse said some states like Kansas use an honor system to report the amount of water farmers use each year. Idaho's ET tracking model can more accurately gauge their usage.

"It's about using the state's water resources in an efficient way," Morse said. "It has to do with how much water an irrigation district ought to get in order to satisfy its customers and users. It's about trying to allocate a scarce resource in as efficient way as possible."

Idaho uses its satellite-based Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) model to compute ET. METRIC uses digital images from Landsat satellites - the only operational satellites that have enough resolution to map ET in individual agricultural fields - which lets the state track how much water is used by each field. Temperatures are determined from the digital image's pixels, which creates a continuum between "no ET" and "maximum ET" to identify areas of water use.

Idaho's use of METRIC was one of the top 50 programs in the 2007 Innovations in American Government Award competition held by the Ash Institute for Democratic Governance and Innovation.

During a drought, the information the program provides would aid the state in determining how much water an entity should be allotted, Morse said. Officials can review an entity's historic water use and make an educated decision about how much water it can use under the new conditions. "During a drought, of course, you have competing interests, entities compete for water," he said. "And understanding the history of water use by an entity is very important."

Elaine Rundle Staff Writer