Wetted tape method

Wetted tape method

The wetted tape method is a very accurate way of measuring depth to water and can be used readily for depths up to 80 or 90 feet.

First, a lead weight is attached to a steel measuring tape.

The lower two or three feet of the tape is wiped dry and coated with carpenter's chalk or keel before taking a reading.

The tape is let down in the well until a part of the chalked section is below water, with one of the foot marks held exactly at the top of the casing or other measuring point.

The tape is then pulled up.

The wetted line on the tape can be read to a fraction of an inch and this reading is subtracted from the foot mark held at the measuring point to get the actual depth to the water level.

A disadvantage of this method is that the approximate depth to water must be known so that a portion of the chalked section is submerged each time to produce a "wetting line."