Tips and Tools for Measuring Pond Area and Volume Like a Pro

Finding both the surface area and volume of your pond, lake, or dugout can be an important step in pond maintenance. These are generally important measurements to be aware of when you have a property with bodies of water. The size of your water body will affect the amount of treatment you will need to apply or what systems you need to install as well as generally influencing parameters such as temperature, dissolved oxygen and nutrient concentration. Depending on the shape and size of your pond there are multiple methods to suit your needs and equipment.

For small ponds:

If you have a small koi or decorative pond the easiest method for volume may be simply measuring the amount of water that it takes to fill the pond, when constructing or cleaning, drain your pond and while refilling measure the volume you add until it is at the desired level. To do this you can incrementally add water using something such as a 5-gallon pail keeping note of how many times you add a full bucket. If you do not want to drain the water you can use the same methods as suggested below for larger bodies of water. 

For medium to large ponds: 

An effective method for finding the surface area of your pond is to use Google Maps. This should be done on a laptop or desktop computer for best results. Turn on the satellite imagery (in the bottom left corner of your screen) and verify that the pond is generally the same as it is currently (it is best to not use outdated images). 

After finding the body of water you would like to measure on the map, right-click to bring up the menu and click the “measure distance" option. After clicking this you will be able to click to add points around your pond, follow the general shape of your shoreline adding points as close together as you deem necessary, generally adding more points to follow all of the fluctuations will increase the accuracy of the measurement. Once you have looped back to your first point click on it again to complete the shape. This is important as not doing so will not allow you to see the area measurement just the distance of the perimeter. When the shape is complete the surface area and perimeter will both be displayed on screen.

If there are no images on Google Maps that will work for measuring your pond another method is a good old tape measure. Depending on the shape of your water body this may be more or less difficult, for a square or rectangular shape the process will be quite easy, measure each side and calculate the area. For a circular pond, if possible, measuring the diameter of the pond would be ideal. Irregularly shaped ponds will need to be measured similarly to Google Maps but on the ground instead, pick points along your shoreline and measure between them adding it up as you go. Keeping a drawing or note of the pond and adding your measurements to it may be helpful. Or just take a rough measurement of the outline in a rectangular shape. Finding out the exact size of your pond is not the goal, finding a close estimate is sufficient for pond treatment and maintenance.

Depth:

Once you have found the perimeter measurements and surface area of your water body the last measurement needed to find the volume is the depth. This process can be quite simple, using something such as a boat to get around on the water you can measure different depths throughout the water body. It is important to get multiple measurements because there will be natural fluctuations in the depth of your pond, the larger the body of water the more depth measurements should be taken to find an accurate average. To do the measuring, prepare a rock or weight tied to the end of a long rope and bring a tape measure along. Drop the weight to the bottom, grab the rope at the point just above the surface and reel it back in making sure not to lose track of where the water level went up to, then use your measuring tape to find your depth. A large stick or piece of wood can even be useful depending on how deep your pond is. Using what you have on hand will make the process cheaper than buying expensive equipment. To make it even easier, pre-mark out lengths on your rope using tape so that when you are on the water you only have to drop the weight to the bottom and read the measurement. There is also the option of using a fish finder or sonar device to read the depth at different points as this is usually a standard reading taken on one of these devices. When you have completed an appropriate number of measurements take the average and use this for the volume calculations.   

Water volume calculation:

Volume = (Pond surface area) x (Average depth)

Example:

Surface area = 32,500 sq ft

Average depth = 6.2 ft

Volume = (32,500 sq ft) x (6.2 ft)

V= 201,500 ft3

To convert to US gallon, multiply your cubic foot volume by a factor of 7.48.

201,500 ft3 x 7.48 = 1,507,220 US gallons

Now that you have an approximation of how much water you have in your body of water you can use the information to make informed choices about treatment and ecosystem health! For more information contact our team at sales@pondpro.ca. Also download our Pond Pro app to make the process even easier!