Knowing the surface area and volume of your pond is extremely important. It is necessary information to add pond chemicals, dyes or even to properly aerate your water. Although this may seem like a daunting task, it really isn’t as difficult as it may first appear. (All length and width measurements are made in feet.)
How to Find Surface Acreage
For ponds that are basically rectangular:
- Multiply the length of your pond by the width of your pond (this will give you the square footage).
- Divide the square footage by 43,560. The result is your surface acreage.
For ponds that are basically round:
- Multiply half of the pond width by half of the pond width.
- Multiply your result by 3.142. The result is your square footage.
- Divide your square footage by 43,560. The result is your surface acreage.
For large, irregular ponds and lakes, give us a call and we can use satellite imagery tools to measure your surface acreage.
How to Find Acre-feet (Volume)
Multiply your Surface Acreage by the average depth of your pond. The result is a volume measurement known as acre-feet.
For example: If your pond is 2 surface acres, with an average depth of 10 feet, your pond volume is 20 acre-feet of water.
How to Find the Average Depth of Your Pond
Depending on the size of your pond, you will probably need a small boat, canoe or kayak. Weight the end of a chain or rope. Take the rope out to the middle of your pond (wherever it is likely to be the deepest) and slowly let the weighted chain or rope down, until you feel the weight hit the bottom of the pond. Knot the rope or tie a string right above the water line to mark the water depth. When you get back to shore, measure the length from the weight to your waterline marker.
The average depth is usually approximately 2/3 of the depth at the deepest point, so simply take your measurement and divide by 3 then multiply by 2.
And there you have it! Of course if you hated algebra class, don’t worry, give us a call. We are always happy to answer your pond questions!