WASTED WATER IN CA

In THEORY based on 2 MILLION POOLS

(if anyone knows the exact number of AG+IG pools in CA please reply in comments)Here is the formula:Length * Width * Average Depth * Multiplier = GallonsDetermine the Multiplier:Rectangle, square, or free-form pool:multiplier = 7.5.Round or Oval pool: multiplier = 5.9So if in theory there were 2 million pools in CA and we average the aboveground and inground multiplier to 6.5; then average the pool size to say 12x26 and a depth of 5 feet (just a guess but probably realistic); then using the FORMULA: 12x26x5x6.5 = ~ 10,000 gallons of water per pool rounded down for easy calculation.Now 2 million pools times 10 thousand gallons completely evaporating each year as a rate of pool water evaporation equals:20,000,000,000 gallons of water is evaporating in CA alone...that's 20 BILLION GALLONS of preventable waste!If a city water tank capacity is 3.5 million gallons then there are ~5,715 city water tanks being wasted in CA each and every year by uncovered swimming pools.Now then, water savings via the use of inexpensive buoyant pool covers is easy to calculate given the evaporation rates in inches published by the National Weather Bureau. (http://www.grow.arizona.edu/Grow--GrowResources.php?ResourceId=208).Once the problem with removal and handling these inexpensive covers has been solve (i.e. managing the covers in sections like pieces of a puzzle for odd-shaped pools) it is not equitable to neighbors without pools to watch their lawns dry up while neighbors with pools continue to waste water that could be prevented through use of pool covers.Taxing those pools with a $50/year tax however provides some equity and those pool owners can recoup their costs via lower water and chemical costs, and the tax revenues can be used to hold down water rate hikes on the average user without pools.Comments encouraged !!

The total number of swimming pools in the U.S. is around 8.6 million as shown here so I doubt that California has 5 million pools given Florida, Arizona, Texas, etc. My guess would be in the neighborhood of 3 million pools, but that's just a guess.

With a large number of above-ground pools, I don't think the average pool size is 15,000 gallons. My guess is an average pool size of 10,000 gallons with more 7500 gallon above-ground pools than 15,000 gallon in-ground pools.

Regardless of the specifics, your point is quite valid that a LOT of water is wasted by having pools remain uncovered. The evaporation rate may be even higher than the link you gave when the pools are heated since higher water temperatures evaporate water faster.

On the other hand, even with 10,000 gallons evaporated in a year, this is around 27 gallons per day so though this isn't good, it's far less than the hundreds of gallons per day used in watering plants and lawns and is roughly the amount used in a shower (depending on type of shower head and length of shower).

I have an automatic mostly opaque safety cover on my pool, but standard solar bubble-type covers also work to virtually eliminate evaporation while they are on. It's a shame they are not used on more pools.

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Richard A. Falk December 8, 2009 at 2:00am

Rex, I'm not sure you saw the link I put in my post below (the link is here) which is market study for swimming pool equipment and they estimate the U.S. market as 8.6 million swimming pools (the study has a date of May 1, 2007).
David Hoff December 4, 2009 at 12:18pm

Here is an updated calculation based on your recommendation of averaging 10,000 gallons per pool:

WASTED WATER IN CA

In THEORY based in 2 MILLION POOLS
(if anyone knows the exact number of AG+IG pools in CA please reply in comments)

Here is the formula:

Length * Width * Average Depth * Multiplier = Gallons
Determine the Multiplier:
Rectangle, square, or free-form pool:multiplier = 7.5.
Round or Oval pool: multiplier = 5.9

So if in theory there were 2 million pools in CA and we average the aboveground and inground multiplier to 6.5; then average the pool size to say 12x26 and a depth of 5 feet (just a guess but probably realistic); then using the FORMULA: 12x26x5x6.5 = ~ 10,000 gallons of water per pool rounded down for easy calculation.

Now 2 million pools times 10 thousand gallons completely evaporating each year as a rate of pool water evaporation equals:

20,000,000,000 gallons of water is evaporating in CA alone...that's 20 BILLION GALLONS of preventable waste!

If a city water tank capacity is 3.5 million gallons then there are ~5,715 city water tanks being wasted in CA each and every year by uncovered swimming pools.

Comments encouraged !!
David Hoff December 4, 2009 at 12:00pm

Here is the 2002 article (partial) scanned.

2004-Study.jpg
Richard A. Falk December 3, 2009 at 12:35am

The total number of swimming pools in the U.S. is around 8.6 million as shown here so I doubt that California has 5 million pools given Florida, Arizona, Texas, etc. My guess would be in the neighborhood of 3 million pools, but that's just a guess.

With a large number of above-ground pools, I don't think the average pool size is 15,000 gallons. My guess is an average pool size of 10,000 gallons with more 7500 gallon above-ground pools than 15,000 gallon in-ground pools.

Regardless of the specifics, your point is quite valid that a LOT of water is wasted by having pools remain uncovered. The evaporation rate may be even higher than the link you gave when the pools are heated since higher water temperatures evaporate water faster.

On the other hand, even with 10,000 gallons evaporated in a year, this is around 27 gallons per day so though this isn't good, it's far less than the hundreds of gallons per day used in watering plants and lawns and is roughly the amount used in a shower (depending on type of shower head and length of shower).

I have an automatic mostly opaque safety cover on my pool, but standard solar bubble-type covers also work to virtually eliminate evaporation while they are on. It's a shame they are not used on more pools.

This reply was deleted.

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