Category Archives: TRIVIA

Fun and useless information that you really need to know.

Pool Evaporation

Pool Evap ChartTo prevent hundreds of gallons of water from being wasted, MMWD recommends installing a pool cover. Water is lost during the day due to evaporation, and at night, because of evaporation lost through nighttime temperature drop.

To use the chart, measure your weekly water loss at the pool’s tile line (a grease pencil works well to mark the level). Then look up the pool size and amount evaporated on the chart to determine the approximate evaporation loss. For example, 1″ decrease per week from a 16′ x 32′ pool equals 320 gallons of water lost per week.

Please note that this chart does not include “splash out.”

The Dance Of Water: New Insight Into Water’s Strange Bulk Properties

ScienceDaily (Aug. 12, 2009) — Water is familiar to everyone—it shapes our bodies and our planet. But despite this abundance, the molecular structure of water has remained a mystery, with the substance exhibiting many strange properties that are still poorly understood. Recent work at the Department of Energy’s SLAC National Accelerator Laboratory and several universities in Sweden and Japan, however, is shedding new light on water’s molecular idiosyncrasies, offering insight into its strange bulk properties.

In all, water exhibits 66 known anomalies, including a strangely varying density, large heat capacity and high surface tension. Contrary to other “normal” liquids, which become denser as they get colder, water reaches its maximum density at about 4 degrees Celsius. Above and below this temperature, water is less dense; this is why, for example, lakes freeze from the surface down. Water also has an unusually large capacity to store heat, which stabilizes the temperature of the oceans, and a high surface tension, which allows insects to walk on water, droplets to form and trees to transport water to great heights.

“Understanding these anomalies is very important because water is the ultimate basis for our existence: no water, no life,” said SLAC scientist Anders Nilsson, who is leading the experimental efforts. “Our work helps explain these anomalies on the molecular level at temperatures which are relevant to life.”

How the molecules arrange themselves in water’s solid form, ice, was long ago established: the molecules form a tight “tetrahedral” lattice, with each molecule binding to four others. Discovering the molecular arrangement in liquid water, however, is proving to be much more complex. For over 100 years, this structure has been the subject of intense debate. The current textbook model holds that, since ice is made up of tetrahedral structures, liquid water should be similar, but less structured since heat creates disorder and breaks bonds. As ice melts, the story goes, the tetrahedral structures loosen their grip, breaking apart as the temperature rises, but all still striving to remain as tetrahedral as possible, resulting in a smooth distribution around distorted, partially broken tetrahedral structures.

Recently, Nilsson and colleagues directed powerful X-rays generated by the Stanford Synchrotron Radiation Lightsource at SLAC and the SPring-8 synchrotron facility in Japan at samples of liquid water. These experiments suggested that the textbook model of water at ambient conditions was incorrect and that, unexpectedly, two distinct structures, either very disordered or very tetrahedral, exist no matter the temperature.

In a paper published in the Proceedings of the National Academy of Sciences, the researchers revealed the additional discovery that the two types of structure are spatially separated, with the tetrahedral structures existing in “clumps” made of up to about 100 molecules surrounded by disordered regions; the liquid is a fluctuating mix of the two structures at temperatures ranging from ambient to all the way up near the boiling point. As the temperature of water increases, fewer and fewer of these clumps exist; but they are always there to some degree, in clumps of a similar size. The researchers also discovered that the disordered regions themselves become more disordered as the temperature rises.

“One can visualize this as a crowded dance restaurant, with some people sitting at large tables, taking up quite a bit of room—like the tetrahedral component in water—and other people on the dance floor, standing close together and moving slower or faster depending on the mood or ‘temperature’ of the restaurant—like the molecules in the disordered regions can be excited by heat, the dancers can be excited and move faster with the music,” Nilsson said. “There’s an exchange when people sitting decide to get up to dance and other dancers sit down to rest. When the dance floor really gets busy, tables can also be moved out of the way to allow for more dancers, and when things cool back off, more tables can be brought in.”

This more detailed understanding of the molecular structure and dynamics of liquid water at ambient temperatures mirrors theoretical work on “supercooled” water: an unusual state in which water has not turned into ice even though it is far below the freezing point. In this state, theorists postulate, the liquid is made up of a continuously fluctuating mix of tetrahedral and more disordered structures, with the ratio of the two depending on temperature—just as Nilsson and his colleagues have found to be the case with water at the ambient temperatures important for life.

“Previously, hardly anyone thought that such fluctuations leading to distinct local structures existed at ambient temperatures,” Nilsson said. “But that’s precisely what we found.”

This new work explains, in part, the liquid’s strange properties. Water’s density maximum at 4 degrees Celsius can be explained by the fact that the tetrahedral structures are of lower density, which does not vary significantly with temperature, while the more disordered regions—which are of higher density—become more disordered and so less dense with increasing temperature. Likewise, as water heats, the percentage of molecules in the more disordered state increases, allowing this excitable structure to absorb significant amounts of heat, which leads to water’s high heat capacity. Water’s tendency to form strong hydrogen bonds explains the high surface tension that insects take advantage of when walking across water.

Connecting the molecular structure of water with its bulk properties in this way is tremendously important for fields ranging from medicine and biology to climate and energy research.

“If we don’t understand this basic life material, how can we study the more complex life materials—like proteins—that are immersed in water?” asked Postdoctoral Researcher Congcong Huang, who conducted the X-ray scattering experiments. “We must understand the simple before we can understand the complex.”

This research was conducted by scientists from SLAC, Stockholm University, Spring-8, University of Tokyo, Hiroshima University, and Linkoping University. The work was supported by the National Science Foundation, the Swedish Foundation for Strategic Research, the Swedish Research Council, the Swedish National Supercomputer Center and the Japanese Ministry of Education, Science, Sports and Culture through a Grant-in-Aid for Scientific Research.

SLAC National Accelerator Laboratory is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the U.S. Department of Energy Office of Science. SLAC’s Stanford Synchrotron Radiation Lightsource is a national user facility which provides synchrotron radiation for research in chemistry, biology, physics and materials science to over two thousand users each year.

Insight Into Water’s Strange Bulk Properties. ScienceDaily. Retrieved December 3, 2009, from­ /releases/2009/08/090811143716.htm

Water Proverbs

A waster of water is a waster of better.
– Old Irish Adage

When you drink the water, remember the spring

Flowing water never goes bad;
our doorways never gather termites.
– Chinese Proverbs

Don’t empty the water jar until the rain falls.
– Philippine proverb

Don’t throw away the old bucket until you know whether the new one holds water.

Love is like dew that falls on both nettles and lilies.
– Swedish Proverbs

Do not bathe if there is no water.
– Shan proverb

A little rain each day will fill the rivers to overflowing.
– Proverb from Liberia

The frog does not drink up the pond in which he lives.
– American Indian Saying

If you saw what the river carried, you would never drink the water.
– Jamaican proverb

Rain does not fall on one roof alone.
– Proverb from Cameroon

Every peasant is proud of the pond in his village because from it he measures the sea.
– Russian proverb

No one can see their reflection in running water.
It is only in still water that we can see.
– Taoist proverb

Filthy water cannot be washed.

Even if you sit at the bottom of the stream, you cannot be a fish.

If there is a continual going to the well, one day there will be a smashing of the pitcher.

The stone in the water knows nothing of the hill which lies parched in the sun.
– African Proverbs

It’s Raining, It’s Pouring…

February 10th, 2009 10:35am PST

Posted By Elizabeth Cutright 1 Comment WE Mag

It’s been a rainy couple of days here in Santa Barbara, just enough to fill up a few puddles and trigger a few freeway fender benders.  Spring, or perhaps “pre-spring,” showers in southern California always serve to highlight a few normally dormant concerns: mudslides in last season’s burn areas, flooding as a result of clogged storm drains, and beach contamination due to runoff.  But as I watched the rain splash along the street and heard it tripping down the gutter, I once again lamented the fact that rainwater catchment is still not as popular as it should be.

Last fall, I attended the American Rainwater Catchment Systems Association’s (ARCSA) annual conference in Santa Monica, CA. The theme of the conference was “Water—The New California Gold Rush,” and a variety of professional voices presented ideas great and small regarding the justification for and the installation of rainwater catchment systems not only in California, but also throughout the country.

While I mentioned this conference in a previous blog, some of the interesting facts I learned bear repeating:

– Trees are rainwater harvesting machines!  An oak tree can collect and treat 57,000 gallons of stormwater.

– If all of Los Angeles’s rainwater was collected, it could supply half of all the state’s water needs.  (So far, six projects in Los Angeles capture 1.25 million gallons of water every time the city gets an inch or more of rain.)

– The single largest use of electricity in the state of California?  Pumping water to the Los Angeles basin.

– Although the typical human needs around 50 gallons of water per day, the US consumes approximately 150 gallons per person per day.

It seems as if rainwater harvesting is a no brainer, so why isn’t it more widespread?  Do you think communities should do more to promote rainwater catchment as part of a comprehensive water conservation program?  Or is rainwater catchment just a drop in the bucket?

The Hydro-Illogical Cycle

“We welcome the first clear day after a rainy spell. Rainless days continue for a time and we are pleased to have a long spell of such fine weather. It keeps on and we are a little worried. A few days more and we are really in trouble. The first rainless day in a spell of fine weather contributes as much to the drought as the last, but no one knows how serious it will be until the last dry day is gone and the rains have come again.”

(from I.R. Tannehill, Drought: Its Causes and Effects, Princeton University Press, Princeton, New Jersey, 1947)


Unlike other natural disasters, drought does not have a clearly defined beginning and end. As a result, our reaction to drought traditionally has not been timely.

©2006 National Drought Mitigation Center

20,000 Gallon Rain Harvesting System Installed By Homeowner To Offset Drought

WATER EFFICIENCY Magazine May 1, 2009

Monte Sereno, CA – The California drought may appear to have softened because of the last batch of rains, but Monte Sereno resident Jerry Block isn’t having second thoughts at all about having one of the largest rain collection systems in the Santa Clara Valley recently installed in his back yard.

You may wonder why he installed this system when he’s only saving a few hundred dollars a year. Jerry feels it’s all about being sustainable and preparing for the unknown.

“What if there is an earthquake and what if the drought continues?” says Jerry, “At least I will have water for my family and neighbors. Rainwater can also be used for fire suppression, irrigation, washing your car and even for keeping your swimming pool filled.“

On the surface, the news that Sierra snowpack measurements show water content at 81 percent of normal appears to be good news. But the Department of Water Resources (DWA) reports that the economic impacts of the California drought — now in its third year — will be devastating.

“Central Valley farm revenue loss is estimated to range between $325 million and $477 million,” according to Governor Arnold Schwarzenegger’s California Drought Report. “Total income losses to those directly involved in crop production and to those in business related to crop production is estimated to range between $440 and $644 million.”

The result of the sustained drought, according to the report, will be an estimated loss of 16,200 to 23,700 full-time equivalent jobs.

“The overall water supply situation has not improved enough to make up for the two previous dry years and low reservoir conditions,” says DWR Director Lester Snow. “Water storage is about five million acre feet below average.”

Jerry is being sustainable about his efforts with his newly installed rain harvesting system because it saves the water agency electricity from not having to pump 20,000 gallons of water to his home anymore.

Collecting this much rainwater significantly reduces stormwater runoff and erosion problems. That’s 20,000 gallons less rainwater that could get contaminated by the time it gets to a stream or an underground aquifer. With the craze of the Victory Gardens, as popularized by Michelle Obama, rainwater catchment helps assure that water will be available for growing home gardens during hot summer months.

There are many benefits to a rain collection system that many times are overlooked, as described by John Lewis of Rain Harvesting Systems.

“Most people don’t really understand the sustainable reasons for having a rain harvesting system installed,” comments John. “The return on investment may never come, but having a rainwater supply is more than valuable, it’s responsible.”

Fremont based company Rain Harvesting Systems installed four 5,000-gallon rainwater tanks to achieve the 20,000 gallon capacity.  Gutterglove Gutterguard was used on the roof gutters for filtering out all the leaves, pine needless and sand from the four rain tanks.

Tim Pope, president of the American Rainwater Catchment Systems Association (ARCSA), sees a growing demand for information about collecing rainwater.

“Rain harvesting is growing tremendously in the United States, especially in California,” said Pope. “California seems to wait for a catastrophe (drought) before it goes after a cause like collecting rainwater.”

Pope recently led a two-day rainwater harvesting workshop in San Francisco, where demand for education is particularly high. The workshop prepares individuals and business owners for the ARCSA accredited professional test for rain harvesting.