Best Practice Guide

Commercial Office Buildings

Introduction

Planning an Energy Program

Funding and Approval

Lighting

Building Envelope

Central HVAC System

Distributed Generation

Demand Response

Commissioning

Procurement Policy

Water Use

Water Audits

Bathroom Fixtures

Landscaping and Outdoor Areas

Education

Energy Efficiency in Telecommuting

Resources and Appendices

Lessons Learned


Adobe Systems Incorporated and Cushman & Wakefield

Arden Realty and next>edge

Cypress Semiconductor

Equity Office Properties

Glenborough Realty Trust

Natural Resources Defense Council

Qualcomm

Swinerton, Inc.

Transwestern Commercial Services


View the Glossary

Water Use

Landscaping and Outdoor Areas

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Greywater system at NRDC's Santa Monica offices. Photo by Grey Crawford, courtesy of NRDC.View Details.

Non-residential landscape irrigation accounts for approximately 7.5 percent of all urban water in California; residential irrigation uses another 27 percent of urban water. However, not all of this water is necessary to keep the grass green.

Drip Irrigation
Proponents of drip irrigation systems enthusiastically proclaim the significant water savings of drip irrigation versus the traditional overhead sprinkler systems. Yet drip irrigation was designed as a way to improve plant health and crop yields - water savings are an added bonus.

To understand this, think of a plant as a person who must choose between guzzling a bucket of water in one sitting or sipping multiple glasses of water over time as their thirst dictates. Similarly, a plant can only consume a limited amount of water at any given time; excess water tends to run off and is wasted. Over-saturation actually drowns roots, causing plants to wilt and die. In sandy or gravelly soil, over-saturation can also lead to deep penetration where water moves rapidly past the root zone and is wasted.

Another advantage of drip irrigation is the control over where water goes. Or, to put it another way, where water does not go. Pavements (and people) stay dry, weeds in adjacent areas are discouraged, and brown spots caused by uneven watering can be completely eliminated. This means less maintenance in addition to lower water bills.

Even turf can benefit from drip subsurface irrigation systems. Drip is especially good for conquering such common lawn watering problems as awkward shapes and sizes, steep slopes, or narrow strips.

Remote Controls and Evapotranspiration
Automated irrigation systems run the gamut from a simple timer affixed to a faucet that turns water on and off at regular intervals, to complex digital remote controls that communicate with satellite weather stations. New advances have enabled digital systems to calculate local evapotranspiration rates (water loss due to evaporation from the soil and transpiration from the leaves), which are then transmitted to irrigation controls so that watering schedules can be automatically adjusted.

Regardless of the sophistication of a system, irrigation controls reduce maintenance time, require less water, and improve plant life - all of which saves money while enhancing the beauty of your landscape.

Xeriscaping
When evaluating water efficiency measures for large landscapes, first consider your choice of plants. By selecting native species that naturally thrive in California's unique climatic conditions, the need for intensive irrigation is greatly reduced or eliminated. This is known as xeriscaping. Native plants are particularly good for attracting special neighbors, like migrating birds and butterflies.

Parking Lots and Porous Pavement
Paved surfaces cover about 43,500 square miles in the continental United States, roughly the same area as the state of Ohio. These impervious surfaces contribute to urban heat islands and cost cities and counties millions of dollars for treatment of the subsequent stormwater runoff.

Porous, or permeable pavement, on the other hand, allows rainwater to penetrate paved surfaces and move into underground reservoirs. Eventually, this water joins natural groundwater, where it helps recharge local aquifers.

Porous pavements cost roughly the same to construct as traditional pavements, and may even be up to 25 percent cheaper. Although the financial return for individual companies is relatively low compared to higher return investments, there are significant benefits for the local community. Porous pavements help treat water by filtering out pollutants before they enter the groundwater and fresh water resources. Porous pavements also lessen the need for curbing and help prevent storm sewers from overflowing. Drivers benefit, too, since these surfaces offer better skid resistance.

Business Examples

The Natural Resources Defense Council installed porous pavement in courtyards and walkways, allowing stormwater to percolate into the ground instead of running down storm drains. Native plants used in the landscaping are watered with rainwater collected in one of two 1000-gallon cisterns.

Swinerton, Incorporated, landscaped its rooftop garden terraces with native plants to reduce storm water runoff and solar heat island gains. Native plants require less irrigation water and help support local wildlife.

Qualcomm, Incorporated, utilizes reclaimed water for its landscape irrigation. Landscaping also takes advantage of drought-tolerant plants and designs. Inside its buildings, Qualcomm has installed automatic shutoff fixtures at all sinks.


Resources

Morrison, J. and Gleick, P., Freshwater Resources: Managing the Risks Facing the Private Sector. The Pacific Institute, August 2004.

Wolff, G., Cohen, R. and Nelson, B., Energy Down the Drain: the Hidden Costs of California's Water Supply. The Pacific Institute and the Natural Resources Defense Council, August 2004.

California Integrated Waste Management Board, Xeriscaping: Establishing a Water Efficient Landscape.

Detroit News, Everyone Undervalues the True Worth of Water. June 19, 2003.