Water Math: Pools v Lawns v Xeriscaping

May 10th, 2012

I was thinking about how I could save more water at the sink, then thought:
QUESTION:  how much water evaporates from an uncovered pool?
ANSWER: 200-300 gallons per WEEK (Marin MWD). In Redwood City, that would cost
about $12-15/mo (but our rates are scheduled to increase soon)  and that’s before splash replacement, what people and dogs drip out. An older pool with leaks could increase that evaporation many times over.

Surprisingly, most evaporation occurs in autumn when water temperatures are
high and air temperatures are cold (especially at night).


You can eliminate 80% of evaporation with a pool cover.

A lawn v pool study for Sacramento (much hotter & dryer than Redwood City)  figures that a pool still uses less water than a lawn.

A lawn the size of a pool uses 4,270 gals divided by 748 gal/unit = 5.71
units X $6.2/unit =$35/mo to water a swimming pool-sized piece of grass.


So… 1) don’t swap out your pool for a lawn

2) Cover your pool when not in use

3) If you’re eliminating the pool (pool maintenance is getting pricey) replace it with native and drought tolerant plantings that don’t require much water after they have been established.

Sustainably Yours,


3 Responses to “Water Math: Pools v Lawns v Xeriscaping”

  1. Filip Norman on August 28, 2012 9:48 pm

    Very good allocation man! I'm simply satisfied through knowing about Pools v Lawns v Xeriscaping. Its really touching view from all side. Thanks mate

  2. Littleton Xeriscape on April 30, 2013 1:42 am

    Xeriscaping is really the best answer for those who are seeking for low water bills.

  3. Broomfield xeriscape on June 19, 2013 8:32 pm

    So the only solution for this is to cover your pool when not in use. Good thing that I didn't swap our pool to a lawn.