What is water's evaporation rate, and how would I slow the rate of evaporation?

Question

I am trying to build a farm pond, and I want to restrict evaporation because I live in a dry area.

Answer 1

Evaporation rate is dependent n temperature, wind, surface area.
The rate increases as the temperature increases, it increases with more surface area, it increases as wind blows dry air over the pond that is less saturated with water than the air right oer the pond.
Keeping the surface area smaller would help. Shade it from solar heating.
Make it deep, keep it shielded from dry breezes.

Answer 2

Pond Evaporation Rate

Answer 3

The rate of evaporation is dependant on several factors:

(1) Temperature of the water. The warmer it is, the faster it will evaporate. At boiling point (100 degrees celsius at sea level) it jumps to a very high rate of vaporization. Even frozen water will convert to a gas at a low rate in a process called sublimation.

(2) Air pressure. As air pressure decreases, water will evaporate more quickly. This is why many food packages have directions for preparation at sea level as well as higher elevations (e.g. Denver which is 1 mile in elevation). If you were camped on Mt. Everest, it would take you a very short time to boil a pot of water. In the vacuum of space, water vaporizes very quickly. If you were floating up there with no protection, your blood would boil. Wind will help to increase the rate of evaporation because it tends to lower air pressure in the vincinity of the place where it is blowing, and it will also push away the air that has already soaked up water vapor at the water surface.

(3) Humidity. On a humid, sticky day, water evaporates much more slowly than when it is dry.

(4) Water purity. Some materials when added to water will change its boiling point and also the rate at which it evaporates.

So I would think your best way to restrict evaporation is to keep the temperature low (using shade, and making the water level deep), and to try to shelter it from wind. Putting it close to a building or fence would help keep the wind away.

One thing you can try is to add something to the pond like lily pads (real or artificial). The third link below contains info about a product called the Faux Lily Pad Light that floats on water. See last link for a place that sells living lily pads.

Answer 4

Make sure you have few to no trees around the pond, the will absorb and use up a lot of the water. Also make sure you dig the pond plenty deep enought and that you use a good clay to reinforce the dam, otherwise it will leak. You also want to pick a spot that has a lot of water running into it. This is called the drainage area. The larger of a drainage area that drains into your pond, the better it will stay filled. Then just make sure you set the overflow at the right height and make it the right size and also that you set the emergency overflow at the right height.

You can't really do much to control the evaporation. That is mainly going to depend on the surface area of your pond and the temperature in your area.

I tried keeping to things that will help keep it filled.

Answer 5

well the evapoation rate is going to depend on the area of water exposed to the air, the temperature of the water, the humidity% of the air. SInce you live in a dry climate, I'm assuming it will be on the hot side, so you you will probably do best by increasing the depth of the pond and minimizing it's surface area. I know this may be contrary to the goals in mind but is the only thing you can do short of putting a tarp over it.

Answer 6

Rates differ with air temperature, humidity, surface water temperature, turbidity, salinity, etc.
Limiting direct sun will help, plant shade trees or use shade cloth if it is small enough.
Cut wind on the water surface by putting up fencing, placing soil berms, or planting at least on the prevailing wind side.
These will help a bit but you are at the mercy of nature. Size and depth (as well as money) determine how you will fair and what you can do.

Answer 7

The best way is to make it deep to decrease surface area, and shade it, as evaporation is proportional to temperature. Put a liner on the bottom to eliminate percolation.

Answer 8

partially covering it so that evaporated molecules have a chance to bounce back into the pond or somehow keeping it cool (like with shade) will reduce the evaporation.

Answer 9

This may sound dumb, but fill it with Ping-Pong Balls or some other floating balls. This will decrease surface exposure and significantly reduce evaporation. This would be good along with some of the other suggestions hear?

Answer 10

A lake in the summer time loses about 1/8 inch of water a day. Sorry I can't give you a source, just heard it on TV one time.