Necessity Breeds Invention

Sept. 1, 2009

The drought in California that began in 1987 and continued into the early 1990s was the catalyst for integrated resource planning at California water agencies. Much of the new demand and forecasting software technology grew out of the demand for water resource and conservation forecasting tools. With droughts now affecting areas east of the 100th meridian, utilities across the country are realizing the importance of what California found critical in planning its water future.

In 1991, nearly 100 urban water agencies and environmental groups that had formed the California Urban Water Conservation Council (CUWCC) signed a memorandum of understanding (MOU). They pledged to develop and implement 14 comprehensive conservation best management practices. Since then, the Council has grown to 398 members.

Implementing these best management practices produced, or spurred the development of, software technology for implementing and monitoring conservation measures. CUWCC’s resource center at its Web site,, provides a variety of guidebooks and software, including free best management practices (BMP) water audit software from the American Water Works Association.

As more utilities outside of California adopted water resource planning in response to droughts in the eastern US a decade later, a drive to form a national entity patterned after CUWCC led to the formation of the Alliance for Water Efficiency (AWE) to take the message of water conservation and efficiency national. Incorporated in 2006 as a stakeholder-based 501(c)(3), it opened its office in September 2007, in Chicago, IL. Mary Ann Dickinson, CUWCC’s first executive director, moved to AWE when it started up. She declares, “Software solutions is the name of the game [for water conservation].  Everyone is writing software!”

AWE advocates for water efficient products and programs and provides information and assistance on water conservation efforts. Its resource library, at, contains a wealth of information on water conservation programs, water loss control, drought, metering and submetering, codes and standards, toilet testing results, and much more. It asked David Mitchell, an economist with M Cubed, to develop the water conservation accounting tool discussed below.

First Came IWR-MAIN
IWR-MAIN is the ancestor of all water resource forecasting software. The original version was developed in 1968 by Hittman Associates for the US Office of Water Resources Research, based on efforts by academic researchers in 1966 and 1967. It was first identified as the MAIN system, an acronym for Municipal and Industrial Needs. The first version concentrated on variables affecting residential water use and had separate models for indoor use, summer use, and use in the eastern and western US. Its disaggregated water use forecasts were for metered and flat-fee residential, commercial, industrial (by Standard Industrial Classification codes), and unaccounted public use. Version 2, in 1969, included growth projection models.

By 1982, version 2.1 was modified to run on the CDC computer for the US Army Corps of Engineers Institute for Water Resources, and it developed follow-on versions 2.2, 2.3, and 2.4. IWR-MAIN Version 3.0, in 1985, provided new more sophisticated models for residential, commercial, and industrial water users.

The Army Corps’s IWR then contracted with Planning & Management Consultants Ltd (PMCL) to further develop IWR-MAIN applications including modifications that moved it from main frames to personal computer applications. In 1986, version 4.0 was released for use on personal computers with data entry screens.

Bill Davis, senior economist with CDM, was at PMCL during that time and participated in its development. He says the company developed conservation algorithms and produced a user’s manual for the Army Corps and IWR widely distributed version 5.1, released in 1987. The company continued to make other modifications and updates into the mid 1990s. By the time versions 6.0 and 6.1 were released in 1994 and 1996, respectively, the Army Corps attorneys told PMCL it could have the copyright, says Davis, and IWR-MAIN became the property of PMCL.

In 1999, versions for Windows 95, 98, and NT were developed, and are still available.  IWR-MAIN had operated on DOSS until that point. In 2003, PMCL was acquired by CDM. “We are now doing customized models that we develop with utilities,” says Davis.

Davis says the PMCL team was working with water utilities, using IWR-MAIN to do forecasting during its evolution. By the late 1980s and early 1990s, the company started developing customized software for water districts such as the City of Phoenix, AZ; the Metropolitan Water District in Southern California (MWD); and the Southwest Florida Management District. For example, he says, “We used their billing data and customized water demand models of residential water use to replace the standardized operating model.”

IWR-MAIN today is an advanced spreadsheet model used as a tool for water demand forecasting and assessing water conservation savings for integrated resource planning. It has two components: the forecast manager and the conservation manager. The forecast manager estimates water demand forecast by customer sector, based on modeled water use patterns. The conservation manager estimates water demand by end uses and provides estimates of water conservation savings. Davis pointed out that the much younger DSS model discussed below mimics the trademarked conservation manager component.

Davis says the Windows version requires that the user input the water demand numbers into IWR-MAIN for base cases and forecasted housing and employment units. This is represented most simply by the question, “What is the gallons per day, times the population forecast?” In the residential sector, this can be represented by water use per household, times projected households. In the nonresidential sector, it can be represented by water use per employee, times the number of projected employees.

The residential sector can be further identified by income, marginal price, precipitation, temperature, and lot size, for example. A model for lot size can be modified as lot sizes increase or units per acre increases. These numbers can then be multiplied to forecast future water demand. Different areas can be differentiated to model predicted water use in a variety of areas.

The conservation manager can be set up by sector, years, and unit area, similar to the forecast manager. Levels of efficiency for each end use, saturation by efficiency levels and intensity of use can all be specified by sector. For example, conversion of non-conserving toilets in households to conserving or ultra-conserving toilets and the resulting savings can be forecasted using the conservation manager.

“We have developed sophisticated models for the City of San Diego [CA], Miami Dade County [FL], and the Central Puget Sound Water Supply Forum,” says Davis. For example, Tampa Bay, FL has the most critical water supply shortages, but the Suwannee River District has a relatively abundant water source. The conservation, reuse, and restoration plans across Florida are quite varied, and the forecasting model must be adapted to reflect the needs of each district, Davis says.

Brandon Goshi, manager of resource analysis at MWD, touted the district’s adaptation of IWR-MAIN. MWD is a consortium of 26 cities and water districts that provides drinking water to nearly 19 million people throughout southern California.

After the district obtained IWR-MAIN 20 years ago, it changed the equations in the software to reflect southern California’s overall water use conditions. This customized version is being used at MWD today, he says. The methodology is an econometric model that measures the varying importance of various factors, Goshi says. Other newer software technologies use straightforward accounting of users. “To us, the econometric model is most robust and most scientific on water use,” he says.

Simulated Water Systems
“If you’re a water utility, and users are growing and supplies are shrinking, what do you do?” asks Gary Fiske. He and a colleague developed a software model, called Confluence, to answer that question. Gary Fiske and Associates is located in Portland, OR.

The idea of Confluence is to compare different strategies in a simulation of a water system assuming different hydrologic and weather systems, Fiske says, and allows decision makers to make informed decisions about what to do. “Basically, system supplies and configuration can be added and edited on an interactive system schematic,” he says. A variety of surface and groundwater supply alternatives, storage facilities, transmission links, treatment plants, demand nodes, and conservation programs can be added in an attempt to foresee the demands in each period, subject to the local flows and temperatures and precipitation in any given period.

For example, Fiske proposed that to see how a water system might perform in 11 years, assuming it had faced extreme drought conditions already, the simulated system can be beefed up, resources added, and various conservation programs instituted. Confluence could tell the utility’s planners how their system will function in 2020 and how far down the reservoir would be drawn.

Confluence does not develop a forecast, Fiske explains. The forecasting variables such as profiles of users and the different geographic areas in the service territory have to be developed by the utility planners and inserted in the software. Confluence allows the planner to ask questions, then find the answers in the simulation model: What is the least costly way to serve demand? What are the tradeoffs between cost and reliability? Should we spend a lot on conservation or on desalination?

The first primitive version of Confluence was developed about 12 years ago, says Fiske. In the beginning there weren’t models out there that could answer the questions different utilities were asking him and his colleagues. The software was developed in a very evolutionary and elemental process primarily at utilities in the western states, Fiske says. But the logic is applicable everywhere, he adds.

The latest version has the ability to deal with climate change. This module allows detailed definitions of different climate change scenarios to be added to the simulation software, and allows testing of the robustness of alternative strategies against future changes in climates.

A trial version of Confluence is on the Web site,, allowing water agency managers and planners to gain a better grasp of the model, including the new climate change capabilities, and a walk-through of how it might be used, with screenshots of model inputs and outputs. Fiske says it is not a full-blown version, but does contain data for a hypothetical utility to demonstrate how it would run. Actual utility data cannot be added. Anyone interested in buying a full version that includes technical support, can contact Fiske via the Web site.

Water Conservation Accounting Tool
Mitchell and two colleagues founded M Cubed, in 1993, in Oakland, CA, and developed the water conservation accounting tool for AWE to help utilities assess the water savings potential of different conservation measures. The final version was released in June and is available free to AWE members.

Mitchell acknowledges that there are alternative software tools to his. He says Fiske and Tom Chesnutt, with A & N Technical Services, developed similar software for the American Water Works Association.

Mitchell also developed simple conservation models for CUWCC starting in 1992, following the signing of the MOU, by the founding California water agencies as they dealt with the drought at the beginning of that decade. The conservation models and cost effectiveness guidelines were specific to best management practices defined by the MOU and led to a standardized structure that any utility can use. “We developed simple Excel calculations to evaluate specific measures, one at a time,” says Mitchell. He continues to be a technical advisor to the CUWCC.

The new water conservation accounting tool can model up to 50 measures simultaneously. “It’s the type of analysis we have been doing since the 1990s for different water utilities, always on a case-by-case analysis,” says Mitchell. During its development, five utilities beta-tested the accounting tool. The utilities were dispersed across the country–Tampa Bay; San Antonio, TX; Marin, CA; Seattle, WA; and Chicago. “The feedback was encouraging,” and improvements based on the testing were integrated into the software, he says.

Mitchell says the tool is used to define conservation measures by specifying their requirements, how they would operate, and the cost to the utility and the type of targeted customers who would theoretically implement them. This structure provides a framework within an overall demand analysis. The tool can integrate conservation into resource planning.

“You can sort of think of it as a TurboTax program for conservation,” says Mitchell. “It provides a standardized format that helps the utility to ensure the correct numbers are used.”

But he used the cautionary age-old adage that can be applied to all the software being reviewed here. “It’s just a model,” he says. “If you put good data into it, you will get good data out of it.”

Least-Cost Planning Decision Support System
The regional water conservation and demand forecasting model first developed in 1999 by William Maddaus, a consultant in Alamo, CA, and Russell Beatty, at Montgomery Watson Harza in Australia, is an end use model which evaluates demand and water conservation on an overarching regional basis for a 30-year period.

This work is documented in papers describing the studies of 15 counties in the Atlanta, GA, area and 27 agencies in the San Francisco Bay area, written by Maddaus and his staff at his consulting firm, Maddaus Water Management.

The Demand Side Management Least-Cost Planning Decision Support System (DSS) model, breaks down total water production, or water demand, to specific water end uses such as toilets, faucets, or irrigation. This approach allows, for example, the effects of natural fixture replacement, plumbing codes, and observation efforts to be considered in water demand projections. It does not model the supply system.

Maddaus says, “We typically consider about 100 conservation models and evaluate about 50. Those are winnowed down to a short list, and presented as packages to the client. For example, for the San Francisco Public Utility Commission regional study, a DSS model was developed beginning in 2002 for each of the 27 individual wholesale customers to forecast 2030 demand in each wholesale customer service area.

In that model, a detailed benefit-cost analysis was completed starting with a base year, for the chosen conservation models. Thirty-year water savings, benefit-cost ratios, and the cost of water saved are evaluated for each of the 32 measures that were chosen and then packaged in three programs–near-term, more aggressive, and longer-term. Retailers selected those they wanted in their programs.

Maddaus Water Management has worked with over 150 cities and agencies in the past nine years. Based on this work, Maddaus has concluded that demand reductions through conservation of 10% to 20% over 20 to 30 years are often cost effective in many different regions. Savings can be less if the agency has been aggressive with conservation in the past and if it has a homogeneous customer base, such as a residential population.

Maddaus has also found that plumbing fixture requirements represent a large portion of water/wastewater savings, even though the 1992 plumbing code has been in place long enough to saturate many residential areas. He believes there is still a large amount of work to be done in the commercial, industrial, and institutional sectors.

Maddaus is continually researching the latest conservation technologies and how they might be applied. For example, Oceanside, CA, is looking into how its many restaurants might cut water use, he says. He suggests getting rid of water-cooled ice machines and old spray rinse valves used to wash dishes. New rinse valves are designed to be low flow.

Maddaus also trains utility staff to use his model. “It’s more of a tool than a glitzy program,” he adds. “The tool helps to evaluate how to know what you’re doing to get valuable information.”

A Water Agency Goes Its Own Way
The Eastern Municipal Water District (EMWD) covers some 555 square miles of western Riverside County in southern California, inland about an hour’s drive from Los Angeles. Currently, 675,000 people live in its service territory. At build-out, it expects to serve 1.5 million people. It provides freshwater, wastewater collection, and treatment and recycled water through retail service to 12 municipalities and wholesale water service to eight cities and water districts.

EMWD gets 80% of its drinking water supply from the Metropolitan Water District, which in turn obtains its water supply from the Colorado River and the California State Water Project that pumps water south from the northern part of the state. Approximately 20% of EMWD’s water supply comes from local groundwater sources, including 4% from desalination.

EMWD promotes the use of recycled water as a policy to conserve and reuse all its water resources. Approximately 60% of its treated wastewater–about 46 million gallons per day–is sold to agricultural and irrigation users. Unsold recycled water is transferred to storage ponds and utilized to meet peak demand and recharge groundwater basins.

EMWD does not use IWR-MAIN, the DSS Model, or Confluence. Instead, it uses specialized software technologies, purchased from vendors for specific tasks. Its major demand forecasts are GIS map-based.

The district’s planner has developed Excel programs that chronicle supply costs, populations, conservation program costs, even proposed housing developments and when they are expected to be built. These data are then collected in a GIS database that was created using ESRI products. A map is then generated based on the GIS database. It vividly pictures EMWD’s system for any given present or future period as new information is plugged into the excel programs.

Joe Gott, director of Information Systems at EMWD, describes the tasks the different software technologies perform for the department. MHW Soft’s H20MAP models the water system, allowing the utility to make the changes on the computer before construction starts on a project to determine how the repairs or construction will impact the system. “It helps to determine flow rates and volumes in different pressure zones,” before ground is broken, says Gott.

Software created by Intermap Technologies produces digital elevation models from its proprietary airborne interferometric synthetic aperture radar technology. EMWD is using it to survey properties and reduce time spent onsite by surveyors to create individualized water budgets for its 135,000 residential accounts.

GIS Analyst Ronald Stenekes says EMWD just purchased Pictometry’s orthogonal and oblique imagery software that provides high-resolution images of buildings. The software allows the user to click around the building’s image on his or her computer to measure its distances, heights, and areas. For example, landscaping can be identified and measured to determine water needs in an area. All of this can be integrated into GIS software.

Finally, EMWD recently installed Municipal Software’s CityView software that will automate and track commercial, industrial, and residential service requests for water and wastewater connections. Furthermore, the software, which went online in July, helps to monitor and update activities associated with new developments along with regulatory compliance and permits.

For example, Gott says, developers are required to go through several steps at EMWD to receive permits. He says this software, which was customized to the district’s needs, has integrated tools to track changes in service. Customers are always asking departments to move faster. “This will improve internal coordination with our planning and environmental departments,” says Gott.

Florida’s Path
Florida’s actions in responding to its devastating drought early in this decade seem familiar to those who watched California go through its drought a decade earlier. However, Florida came up with a different plan. In 2001, the Department of Environmental Protection initiated the Florida Water Conservation Initiative to identify additional measures to increase water use efficiency.

The Initiative’s final report, released in April 2002, identified 51 priority recommendations for improving water use efficiency statewide. This report produced the “Joint Statement of Commitment” to implement the recommendations. Representatives of the DEP, the five district water agencies, the state office of the American Water Works Association, and other state environmental associations signed the joint statement.

One of the principles in the joint statement was to create the Conserve Florida Water Clearinghouse in 2006 that is housed at the University of Florida. The Clearinghouse Web site,, provides a library of publications, learning resources, research, and news. Jim Heaney is the principal investigator and head of the Clearinghouse. He is also professor and chairman of environmental engineering science at the University of Florida, and he is a member of the Board of Directors of AWE.

Heaney says software, called “The Guide,” has been developed for Florida. It is available on the Clearinghouse Web site as an online template for developing goal-based water conservation plans. The Guide is designed to help public water suppliers develop conservation plans that are adapted to individual utility profiles. It also has a guide for monitoring implementation and reporting water conservation results.

Heaney says conservation planning is new for Florida, although utilities in the state had already been doing water planning. Only recently, have enough people started taking interest, he says. At the national level, California’s work has been the lead effort, especially through the CUWCC, he says. Heaney notes that Gary Mitchell’s Confluence model reflects the California school models and takes an approach different from the Guide’s.

Florida’s Guide reflects the wishes of the joint statement signatories and represents a wish list of conservation plans. Each of the five water management districts in Florida has their conservation plan made up of measures, but none are quantifiable, Heaney says. In contrast, the conservation BMPs that California members of the CUWCC commit to are requirements, not suggestions, he points out.

Heaney says there is a real need to incorporate a tracking mechanism in the districts’ conservation plans. Currently, an entity–be it an individual or company–has to obtain a permit to use water from one of the water management districts. Permit holders then submit a water supply plan for approval to the Department of Community Affairs. Heaney’s hope now is to integrate monitoring and tracking mechanisms into district conservation plans, to verify that permit holders are doing what they promise.

About the Author

Lyn Corum

Lyn Corum is a technical writer specializing in water and energy topics.

Photo 140820417 © Susanne Fritzsche |
Microplastics that were fragmented from larger plastics are called secondary microplastics; they are known as primary microplastics if they originate from small size produced industrial beads, care products or textile fibers.
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Photos courtesy Chino Basin Water Reclamation District.
From left: Matt Hacker, Metropolitan Water District of Southern California; Marco Tule, Inland Empire Utilities Agency Board President; Gil Aldaco, Chino Basin Water Conservation District Board Treasurer; Curt Hagman, San Bernardino County Supervisor; Elizabeth Skrzat, CBWCD General Manager; Mark Ligtenberg, CBWCD Board President; Kati Parker, CBWCD Board Vice President; Teri Layton, CBWCD Board member; Amanda Coker, CBWCD Board member.