Measure Well Depth: How Deep is the Well?How to measure water well depth. POST a QUESTION or COMMENT about the procedure to make the basic measurements of a water well: diameter, depth, water level, static head.

You are watching: You stand at the top of a deep well. to determine the depth tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.
How to measure well depth & how to abandon a well that will no longer be used.How to use a string and weight to measure well depth. How much water is in the well? Water quantity & definitions of well depth, water depth, static head, well volume, water quantity are explainedThis article series describes how we measure the depth of a water well. We caution that the amount of water available and the water delivery rate ability of various types of drinking water sources like wells, cisterns, dug wells, drilled wells, and even artesian wells is not answered just by measuring the depth of the well itself, but still we often need to know this number in order to know how to shock the well or how to prepare pipes, controls, and well pump choices or settings.We also provide an ARTICLE INDEX for this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need. How To Measure the Depth of a Water Well
The sketch at page top, courtesy of Carson Dunlop Associates, outlines what happens during a well drawdown or well flow test procedure. The illustration shown here explains that measuring water level in a well requires avoiding getting hung up on well piping, seals, spacers. Source: How to Measure Water Level in a Well, Oregon Water Department, cited below. First you have to find the well. Second you need to know what kind of well is installed: driven point, drilled, or hand dug well, for example.Two Key Questions to Ask About the Water WellIf you are purchasing a property served by a private well of any sort, here are the critical questions to ask about the well itself:Where is the well located?Is the well on the property? Can you find it? Sometimes there is a visible well casing above ground, or a visible protective cover over a dug well. Not always. If you can"t find the well, see WELL LOCATION, HOW TO FIND.What kind of well is it: hand dug well, driven point well, drilled well, spring, stream, (these water source alternatives have implications for sanitation and water quantity as well as safety)Measurements like the well depth, well flow rate, well recovery rate are all useful, but taken by themselves some of these numbers can give a false reading about the basic question of how much water is in the well? What we ultimately need to know is the total quantity of water that can be drawn from the well and the quality of that water: is it potable, hard (mineral laden), smelly, dirty, requiring treatment for any aesthetic or health-concern contaminant? See WELL FLOW RATE and see WELL FLOW TEST PROCEDURE.

Well Depth Measurement Tools, Devices, Procedures

Trimmer (1991) describes three methods to measure water levels in a well: an electronic sounder or depth gauge (device lowered on wire senses distance to water top), a wetted tape (accurate to about 90 ft), and an air line (measures anticipated usage volume not actual well water depth).

Here we describe several more-simple, very low-cost methods for making well and water depth measurements.

A simple steel egg sinker, 3/4oz or heavier can be used with string to find well depth. Adding a simple fishing float and suspending the weight just below the float can be used to find the depth to the top of well water.

These fishing essentials are sold just about everywhere, including online at Bass Pro Shops ( Here are the details:

How to Find the Depth of a Well using a simple String and WeightI"ve used a simple float and weight to measure well depth and the depth to the top of the well water in well bores as well as dug wells. The Water Ace Pump Company as well as other water equipment companies like Flotec® offer a simple well depth measurement procedure that works for drilled wells or hand dug wells. We have added some details.1. Tie a small but heavy weight to the end of a piece of string (be sure there is enough string; some wells are very deep). Lower the weight into the well until it reaches the bottom. I use a steel or magnesium fishing weight.Watch out: be careful putting anything into your well, that you don"t send down a weight that gets hooked on pipes or valves in the well bottom. Use a small (non-lead-containing) fishing weight or a rounded object and tie it carefully. I don"t use a lead weight because if I lose it I"ll have to retrieve it: I don"t want to leave a chunk of lead in the drinking water. 2. Take up the slack and mark the string at ground level. Pull the weight out of the well.3. Measure from the bottom of the weight to the ground level mark on your string. This is the depth of your well.For relatively shallow wells, 30" or less, we sometimes use a tape measure directly, but a weight on a string assures that the line used to make a measurement is absolutely straight, so more accurate.

How to Find the Level of Water Top the Well

Except for artesian wells, the top of the water level in the well will virtually always be some depth lower than the top of the ground surface.

As we explain below, there are reasons we want to know the depth from ground to the top of the water level in the well: to calculate the well"s static head or volume.

Well Water Water Level by Observation

First be sure that the well is in fully-recovered mode. That means that no water has been drawn from the well (the pump is off or no water is being run at the building(s) served by the well for an interval long enough that the well has fully recovered.

See more: Illinois Coalition For Immigrant And Refugee Rights (Icirr)

Just how long you need to wait for a well to recover depends on the well"s static head, and its flow rate or recovery rate. The time may be anywhere from a few minutes to 12 hours or longer.

If you can see the top of water in your well and if the top is not deep in the well, you may be able to measure to the water top using a simple tape measure. Watch out: Take care not to drop the tape into the well, or tie a string from the tape"s belt clip to your belt if you are clumsy like me. Oops I dropped the weight into the well! Ok so have I. I also leaned over a well and dropped a fancy pen that my mom had given me. (I left it there and I never told anybody.) See WELL PIPE RETRIEVAL TOOLS for help getting back stuff you"ve dropped into the well. Well Water Level by Using a String & Fishing FloatIf you cannot see the top of water in your well then you can tie a fishing float or "bobber" to your string and lower it carefully into the well until it stops dropping. Mark the string at ground level. Measure that string length - that"s the depth from the ground surface to the top of your well water. I hang a small light (non-lead) weight below my bobber to help lower it into the well and I take care to avoid snagging the bobber and string on components along the well pipe. Well Water Level by Using a String & Water Finding PasteYou can adapt the string and weight method described above by adding a water finding paste to the upper portion of the string. Water finding paste will turn color (such as pink to blue) where it contacts water. The string and paste will permit you to measure well depth and water top at once if you can first guess at the location of the water top so that you can locate where to put the paste without having to coat the entire string. For a deep well I"d want a long, strong string, a smooth non-jamming weight.Well Water Level Using a String and "Popper" (Pipe cap and nipple)

Flotec® describes using a popper or noise-maker assembled from a 4-6" x 1/2" pipe nipple and cap. The cap is sealed to the pipe nipple and the assembly is lowered into the well, again taking care not to snag the assembly in the well bore.

Flotec explains that when you lift the pipe nipple+ cap (open end down) from beneath the water surface back into the air the assembly will make a "pop" sound that is quite audible. Measure your string from ground level at that point to the bottom of the pipe nipple and you"ve measured the distance from ground level to top of the well water.

What do Well Depth Measurements Mean?

Well depth and well water depth permit you to calculate the static head or volume of water in the well at rest. These procedures are important for matching the well pump capacity to the physical depth of the well opening in the ground.

But knowing the well depth does not tell us much about how much water is actually in the well (though we can calculate that) and it doesn"t tell us the rate at which we can take water out of the well and for how long - the well"s flow rate.

Watch out: measuring the water level in a well is not the same as measuring well depth.

Definition of well depth: the distance from the ground surface to the bottom of the bore hole. Definition of water level: the height to which water rises in a water well when the well is at rest and fully recovered after recent use. Definition of static head: the height of the column of water available to the well pump or foot valve; distance from the water level top to the intake of the pump or foot valve. Multiply the static head height by well diameter or by well volume per foot to determine the actual water volume comprised by the static head. See WELL DYNAMIC HEAD & STATIC HEAD DEFINITION where we explain how we use well depth and the well bore diameter to calculate the actual volume of water in the well in gallons or liters. Definition of drawdown depth: the depth to which the pump lowers water in the well when the pump is running. In a well whose flow rate is greater than the pump"s rate of removing water from the well, the drawdown depth will be somewhere below the top of the static head and the water intake at the pump or foot valve. The drawdown depth of your well is measured when the well driller prepares your well or possibly when your plumber installs a new well pump. Definitions of water quantity and well flow rate: how much water is in the well bore when the well is recovered and at rest? How much water can we actually get out of a well? See WELL YIELD, SAFE LIMITS and see WELL FLOW RATE

How to Find the End of the Steel Casing in a Well Bore

Well Depth Tools, Research, Articles, Methods

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