LEEDing Us to Water – minding conservation

Water Conservation

In the developed world where most of us reading this post live, we tend to take clean water for granted. And we are often wasteful. We even pay crazy prices for it packaged in plastic bottles. Natural mineral water has been elevated to a gourmet status with bottling and labeling rivaling what we find on fine wine racks.

We don’t think much about water consumption in general when in fact globally water is scarce. This is a cruel fact when you consider that nearly 1 billion people in developing countries across the globe do not have access to it. For them, clean, safe drinking water is seriously scarce.

We need water to exist. It is a basic human need and is the foundation of life. The importance of access to clean water cannot be overstated. Water is directly related to our health and wellness. Some water facts:

  • Less than 2% of the Earth’s water supply is fresh water.
  • Each person needs to drink about 2 ½ quarts (80 ounces) of water every day.
  • A person can survive about a month without food, but only 5 to 7 days without water.
  • Buildings consume about 13.6% of the potable water in the US.

So when it comes to being sustainable, water conservation is big. An entire section of the LEED point system is focused on “Water Efficiency.” The New Mexico Office of the State Engineer defines water conservation as “any action that reduces the amount of water withdrawn from water supply sources, reduces consumptive use, reduces the loss or waste of water, improves the efficiency of water use, increases recycling and reuse of water, or prevents the pollution of water.”

Let’s look at the LEED Water Efficiency Credit 3 titled “Water Use Reduction.” We can get up to 4 points if we demonstrate water savings of 40% over the baseline and can get an additional point for innovation and design process if we reduce water by more than 45%. We think that both of these are achievable and will get a total of 5 points. That’s over 8% of the minimum 60 points needed for LEED gold. The USGBC cites the benefits as:

  • Reduction of the total amount of water withdrawn from rivers, streams, underground aquifers and other water bodies.
  • Protection of the natural water cycle saving water resources for future generations.
  • Reduction of chemical inputs at municipal water treatment facilities.
  • Reduction of energy consumption from treatment and distribution.
  • Reduction of negative environmental impacts through end-use efficiency.
  • Decrease in building operating costs.
  • Lessens capital investment needs for municipal water supply and treatment.

That seems like plenty of reasons to pursue these points.

The baseline numbers that we have to beat are:

  • Commercial Toilets                     1.6 gallons per flush (gpf)
  • Commercial Urinals                    1.0 gpf
  • Commercial Lavatory Faucets    2.2 gallons per minute (gpm)


We also have a shower and some sinks that we can include in the calculations. The calculations are based on the number of full-time occupants (FTE’s) and transient occupants (visitors) times the fixture use rates times the plumbing fixture water use. You do this for the baseline flows and calculate it again for the reduced flow fixtures and see how much you reduced the water consumption.


The ultimate high-efficiency urinal is the waterless urinal which was introduced in the 1990’s. Most waterless urinals rely on regular replacement of a vegetable-oil-based fluid and a disposable cartridge to maintain performance of the sanitary trap. Keeping waterless urinals clean and preventing the deposition of salts in the drain line (from you know what) have proven to be problematic. Nonetheless, they continue to be used in slowly increasing numbers although our client was not ready to participate in increasing the numbers.

Here are the flow rates that we have specified for the fixtures to be installed in the Visitor Center for comparison to the baseline numbers above:

  • Commercial Toilets                         1.28 gpf
  • Commercial Urinals                      0.125 gpf
  • Commercial Lavatory Faucets         1.5 gpm

The responsibility for documenting this credit is up to the FSB design team.

Want to test your fresh water savvy? Try the “Fresh Water 101 Quiz.”

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Filed under Design, LEED ®, Materials

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