News

Geospatial Water Modeling Drives
California Water District's Master Planning

For water utilities located in most desert regions of the United States, the problem is finding enough resources. For California's Eastern Metropolitan Water District, it's deciding what to do with them all.

The EMWD encompasses some 555 square miles in the western portion of Southern California's inland Riverside County, extending roughly from the San Bernardino County to San Diego County lines. The area is touched by virtually all of Southern California's major water supply sources, including the State Water Project and the Colorado River Aqueduct.

Such an ample supply of connections to raw water is a hydraulic engineer's dream - allowing for endless creativity in analyzing how to create the most cost-effective, reliable system for future generations. For EMWD, it's a job best managed with geoengineering technology, namely GIS combined with advanced water modeling software.

To date, the combination of these tools had helped develop one of the industry's most comprehensive Water Facilities Master Plans, a plan that includes doubling the capacity of one facility, helping the regional water authority best locate new facilities, and introducing a highly adaptable model capable of accommodating changes in demand, costs and resources at a moment's notice.

GIS and then some

The EMWD, with its exceptional wealth of water sources, currently operates 59 separate pressure zones - a vastly more complex system than most. (The nearby Long Beach MWD, for example, has only two zones.)

A pioneer in the field of reclaimed water, the District has operated an extensive, interconnected reclaimed water system for years. Today, it includes five major state-of-the-art water reclamation facilities. To accurately predict domestic and reclaimed water demands and sewage flows for a system this complex, engineers rely heavily on land use and growth projections.

Before GIS technology, melding these projections into one expansive, revealing picture was an arduous task. Map sub-areas were colored in by hand, based on General Plans collected from all involved cities, counties, and other jurisdictional agencies - each of whom employed its own unique abbreviations, symbology, and updating time frames. When basing a Master Plan on such an inexact science, the tendency was to overdesign.

Even with the arrival of GIS in the early 1980s, the task remained one of the most labor-intensive segments of master plan development for EMWD -- that is until the advent of H₂OMAP™.

EMWD Senior Planner Ruth Newsham, P.E., M.B.A., a seasoned pro who's witnessed the evolution of modeling software since the 1980s, has had a front-row view of how the technology has revolutionized water modeling. “H₂OMAP™ opened up opportunities to strategize cost-effective system improvements that never existed before,” she says. “For example, relocating pump station facilities is expensive and you can't change topography. But you can adjust boundaries. Doing so can enable you to minimize capital investment for new facilities by utilizing existing ones more effectively.”

Using GIS and H₂OMAP™, engineers can change pressure zone boundaries virtually on-the-fly, and instantly see how demands change, while monitoring critical service indicators like pressure and fire flow generated by the proposed changes. Says Newsham, “The tedious task of adding and subtracting acres of multiple land use types, each with its own unique usage factor, is a thing of the past.”

As a follow-up, the EMWD looked to build on its GIS with the power of water distribution system modeling and optimization software - a tool capable of helping engineers and analysts rapidly assess and compare a wide range of existing or proposed systems under various conditions and planning horizons, using both steady state and dynamic simulations. In October 2001, the agency implemented H₂OMAP™. Extremely powerful, flexible, and intuitive, H₂OMAP™ is a comprehensive geoengineering platform that can be used to effortlessly read and share native GIS data, extract pertinent modeling information, and automatically construct, skeletonize, load, calibrate and analyze any network model - saving time and money across the enterprise For EMWD, it provided the opportunity to maintain a single detailed geospatial hydraulic model of its system while quickly developing and evaluating an array of system improvement alternatives.

According to EMWD analysts, every change made cascades through the entire set of projects in a tree-like structure, eliminating the need to update multiple models each time a change is made or a new scenario is applied. Engineers can switch between scenarios, merge models, and compare results instantly - an ideal framework for developing accurate long-term Master Planning models.

Modeling the Future

Recently, Newsham put H₂OMAP™ to the ultimate test as EMWD pushed to complete a new Water Facilities Master Plan. Thanks to spectacular advances in water modeling technology, the large, complex one-and-a-half year project - which would previously have been handled by a costly outside consultant staff of substantial size (15+) - was done completely in-house by a handful of people in the same amount of time.

Several major changes have occurred since the agency's last Water Facilities Master Plan (WFMP) was completed in 1990. Most notable was the slowdown in the growth of new commercial and residential developments, followed by the emergence of a modest growth trend in 1996. This new growth, coupled with an unusually high summer demand in 2001, had underscored a number of deficiencies in the District's distribution system and its available water supply.

At the District's request, the Metropolitan Water District of Southern California (MWD) agreed to increase the EMWD's connected capacity at its Mills Filtration Plant from 155 cubic feet per second (cfs) to 300 cfs. A plan was needed for delivering this increased supply from Mills and expanding or replacing facilities that were now inadequate. In addition, the MWD had delayed the design and construction of a new filtration plant from 2005 to 2018, and the EMWD was collaborating with them to reconsider the proposed location of the facility.

The key goals of the new Master Plan were ambitious going beyond the description of existing water system facilities, historic water use, and projected future demands. This plan was to include an evaluation of the EMWD's existing and proposed “backbone” systems, recommend new facilities, update the district's phased water system improvement program, identify a strategic plan for future sources of water supply, and determine the capital costs of updating the Master Plan.

Even armed with the cutting-edge capabilities and speed of H₂OMAP™, the project proved to be a massive undertaking. The modeling session, consisting of several hundred computer runs and scenarios. lasted nearly twenty hours. Each run was completed instantaneously with only enough time between runs to push output data to a recording device for documentation.

In the process, Newsham became an ardent fan of H₂OMAP™ and its highly advanced capabilities. “Processing time is instantaneous. Analysis results are displayed graphically in any color, size, or format for any variable - flow rate, velocity, head loss, pressure, head and water quality. No more searching long columns of endless numbers for anomalies and praying you didn't miss them,” she smiles.

Even reports are generated in the format of choice. “In the old days, developing facility costs was one of the most nerve-wracking parts of master planning,” Newsham remembers. “Every change - and there are always many - meant hours of work. With tools this sophisticated, making changes is effortless.”

If any user could put those tools to the acid test, it's Newsham. Trained as a concert pianist, she fires off command sequences at the speed of thought. “If anyone can lock up a PC, it is I,” she says. “Most people literally get dizzy watching the screen and ask to leave for a while.” Quite unbelievably, she reports, H₂OMAP™ never crashed during the entire session. “Having worked with so many different hydraulic analysis software products dating back to the dark ages, I was absolutely amazed. I've never worked on a more stable system for performing intricate runs successively, one on top of the other, imposing maximum stress on the system. This is by far the best-performing hydraulic analysis software I've ever used.”

The draft Master Plan was recently released to an enthusiastic reception, with many comments on the comprehensiveness of the document and its many graphs, tables, and figures. The coup d'état, however, was the award-winning four- by five-foot map generated for the project by Charles Crider, an integral member of the Master Plan development team who provided all GIS services during the project.

To create it, Crider exported finalized capital improvement projects totaling millions of dollars directly from H₂OMAP™ into ArcView (ESRI, Redlands, California), color-coded them by phasing, and overlaid them onto a highly detailed set of over 300 aerial photographs joined as one. The stunning result depicts existing facilities of the complex network of pipelines, including nearly a hundred storage reservoirs and as many pump stations.

After some prodding by coworkers who had witnessed its creation, Crider entered the map in the annual Map Gallery competition at the International ESRI Conference in July 2002. To the delight of the entire team, the entry won the coveted People's Choice Award, which honors the submission voted best overall by conference attendees - in this case, over 12,000 professionals from all over the world. Crider has since been besieged with requests to generate similar maps for the many other systems (groundwater, reclaimed, sanitary sewer, etc.) managed by EMWD. But then, fame does have its price.

(Click to enlarge the picture)