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Water Efficiency and California's Mega Drought


Excerpt from the USGBC-LA Existing Buildings Committee Think Tank Report prepared by Verdani Partners on behalf of the USGBC-LA Existing Buildings Committee.

Class A Report | Class B & C Report

California’s Governor Jerry Brown announced a new Executive Order mandating state water restrictions to reduce water usage by 25% over the next nine-months.

Here are the source materials for the mandates:


The current extreme drought in California has exposed vulnerabilities in the state’s water storage and delivery systems. Outdated infrastructure, over pumping of ground water supplies, pollution of ground water supplies by fracking and other activities, conflicting municipal and community policies, climate change, increased demand, and limited access to alternative water sources contribute to increasing water stress.

While Los Angeles has maintained level water use per capita for the past forty years, a result of successful metering programs, population growth has pushed water supplies to the limit. Climate change has also greatly affected the snow pack water supplies and the underground water reserves are been tapped at an unprecedented rate. The state is facing one of its worst droughts in history and a massive effort will be needed to find solutions to meet its water demand needs.

In response to current conditions, Los Angeles Mayor Eric Garcetti signed an Executive Directive on October 14, 2014 to reduce potable water use 20% by 2017. This includes removing turf landscaping at city buildings and replacing it with native and drought-resistant plants. The directive also mandates the Los Angeles Department of Water and Power (LADWP) to reduce water imports 50% by 2024.*

It was also discussed that the cost of water is still quite low which makes the business case for making water efficiency upgrades more challenging. Some of the attendees mentioned that a price signal would be critical to incentivize additional water efficiency upgrades and lower water usage. The LADWP rep explained that because they are a public entity that they cannot charge for the water. They can only charge to transport the water and any rate increases need to be approved by the voters which makes the process for increasing the fees for water very challenging.

A best practice for conservation, and one that has helped Los Angeles maintain the lowest consumption for any city with a population over 1 million, is metering.

LADWP launched their conservation program in the late 1970s. Today, the LADWP provides extensive incentive programs for water use reduction efforts, including prescriptive, or menu-based programs, and more flexible technical assistance programs. While more involved, the technical assistance programs cover a larger variety of costs associated with pre-approved water conservation measures, including consulting fees. Recently, utilization of technical assistance programs has surpassed the traditional menu-based programs, although many building owners interviewed were still unaware of the technical assistance program.

While improving the efficiency of indoor water fixtures has been a popular and well-publicized program historically, utilities have identified cooling towers and outdoor water use as 70%+ of annual building water consumption, making them the target of renewed water conservation efforts, including access to reclaimed water, widespread adoption of rain sensors, reverse osmosis systems, and microfiltration systems.

*As of May 1: The LADWP is seeking the following changes to the current Water Conservation Ordinance:

  • Revised definition for “Baseline Water Usage”

  • Removal of unnecessary water rate references

  • Additional water use restriction of not irrigating within 48 hours after a measurable rain event

  • Additional language in Phase Ill and IV to recommend and mandate pool covers

  • Clarifying language in Phase IV and V to properly address potable water use for pool and aesthetic water features

  • Additional language in Phase IV for watering of sensitive areas at golf courses and professional sport fields

  • Creation of a new Phase Ill which limits outdoor watering to two days a week.

  • Odd-numbered street addresses irrigate on Monday and Friday, and even numbered street addresses irrigate on Sunday and Thursday.

  • Watering times for the new Phase Ill shall be limited to:

  • Non-Conserving nozzles (spray head sprinklers and bubblers)- no more than 8 minutes per watering day per station for a total of 16 minutes per week.

  • Conserving nozzles (standard rotors and multi-stream rotary heads)- no more than 15 minutes per cycle and up to 2 cycles per watering day per station for a total of 60 minutes per week. (With the above watering times, water consumption used for both types of nozzles is essentially equal)

  • Current Phase Ill will be renamed Phase IV and include the following new language to clarify allowable watering durations:

  • Non-Conserving nozzles (spray head sprinklers and bubblers)- no more than 8 minutes per watering day per station for a total of 8 minutes per week.

  • Conserving nozzles (standard rotors and multi-stream rotary heads)- no more than 15 minutes per cycle and up to 2 cycles per watering day per station for a total of 30 minutes per week.

  • Current Phase IV will be renamed Phase V.

  • Current Phase V will be renamed Phase VI.


LADWP provides extensive prescriptive and menu-based programs as well as more flexible technical assistance programs to incentivize water use reductions. The technical assistance programs require more upfront involvement from property managers but also cover a larger variety of costs associated with pre-approved water conservation measures, including consulting fees. In recent years, technical assistance programs have increased in popularity and have surpassed the traditional menu-based programs. These ratepayer-funded programs are offered at no additional cost to residential and commercial customers. By the end of 2014, LADWP will have invested $60 million dollars in water conservation incentive programs.


Building managers can reduce water use by installing low-flow or ultra low-flow fixtures, fittings, and equipment, such as toilets and urinals that exceed current code requirements per recommendations below:

  • Water closets, max 1.28 gallons/flush

  • Urinals, max 0.125 to 0.5 gallon/flush

  • Shower heads, max 1.8 gallons/minute

  • Faucets, max 1.0 gallons/minute

  • Replacement aerators, max 0.5 gallons/minute

  • Metering faucets, max 0.25 gallons/cycle


  • Install metering devices and controls

  • Perform ongoing distribution system audits, leak detection and repair

  • Install native and drought resistant landscape

  • Install rain sensors on irrigation

  • Install drip irrigation

  • Maximize indoor plumbing fixture and fitting efficiency (toilets, urinals, faucets, aerators, and showerheads)

  • Implement a cooling tower chemical management and water efficiency program

  • Utilize recycled water when available

  • Reduce water pressure

  • Insulate Pipes

  • Recover water from cooling towers

  • Steam boiler blowdown

  • Educate users


As water efficiency regulations become more stringent and water rates continue to rise, property owners and operators can reap immediate benefits from low-cost measures such as the installation of aerators and quickly recoup investments in upgrading indoor water fixtures.

To help meet the City’s aggressive water conservation goals, building owners will be encouraged to move beyond upgrades to efficient indoor water fixtures for deeper savings. Cooling towers and outdoor water use account for an average of 70% of building water consumption, making them the target of increased water conservation efforts.

Reclaimed water is currently restricted to limited areas. There are plans to further develop water reclamation projects for Los Angeles, however, its use is limited by state health requirements and the high cost of pumping plants and distribution facilities to deliver water from the reclamation plants to the customers. Robert Estrada of LADWP reports that the cost is an estimated million dollars per mile of purple pipe. However, if Assembly Bill 2282 passes, all new residential and commercial construction with access to reclaimed water will be required to incorporate it into approved uses, such as landscaping, and reclaimed water infrastructure would necessarily expand.

The state’s water supplies are at all times low, underground water supplies are rapidly diminishing and demand for water continues to grow. Solutions to solve our water supply needs will involve many different solutions from efficiency programs to lower demand, a price signal, search for new water sources, importing water and building desalinization plants.


  • Los Angeles DWP: Since 1990, LA Department of Water and Power has spent about $280 million on conservation programs.Los A

  • Metropolitan Water District: Metropolitan provides rebates on water efficient fixtures, financial assistance for water reduction projects, and incentives programs.

  • Mayor’s directive to cut water use: (LA Times article) LA Mayor Eric Garcetti signed an executive directive to further cut potable water use.

  • 20x2020 Water Conservation Plan: Statewide plan enacted in 2010 to reduce water consumption by 20% by 2020.

  • Senate Bill SB X7-7 2009: This Senate bill requires all water suppliers to increase water efficiency.

  • WATERSENSE: A recognized seal of approval for water efficiency similar to ENERGY STAR.

  • DOE water efficiency bmp’s: Water Efficiency Best Management Practices from the US Department of Energy.


  • IPC 2006, section 604: Design of building water distribution system.

  • UPC 2006 section 402.0: Water-conserving fixtures and fittings:

  • International Association of Plumbing and Mechanical Officials:

  • WaterSense Program:

  • Water Sense, a recognized emblem of approval for water efficiency similar to Energy Star. WaterSense, US EPA:

  • US Department of Energy, for water efficiency BMP’s:

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