Water depth

What is water depth?

Water depth is simply the depth of the water at a specific point. In certain areas, water levels have huge effects on ecosystem health. For example, fish spawning.

What does water depth mean for ecosystems?

Water depth naturally fluctuates throughout the season. Tracking depth at times when it is ‘highest’ in the spring and ‘lowest’ in the late summer can give you indications of exceptional drought or flood years. Every area has different fluctuations and baseline values. Over time, you will begin to understand what is usual and out of the ordinary for your body of water.

A woman measures water depth using a secchi disk and reel off of the side of a canoe. She is in deep water.
You can use a secchi disk and reel to measure off of a canoe or dock

Water Rangers protocol

You can use a water gauge attached to a solid structure, or you can use something like a secchi disk and note when the line goes slack. Please be aware that the location you take depth readings from must be consistent! Docks should be anchored and remain in the same spot year round. If you take your dock out every year, your readings will not be as accurate. Note this in your location description.

Using your secchi disc

At Water Rangers, we only record water depth when the bottom is visible at a sample location. Use your secchi disc to record this.

  1. Lower your secchi disk until it touches the bottom, making sure the rope is straight up and down and there’s no slack in the rope.
  2. Pinch the rope, or use a clip to mark where the rope touches the water.
  3. Record the measurement from your graded reel.

Note: Your rope is measured to 10-20m. Not suitable for deep spots.