A large percentage of inquiries at the Facilities Development Department have to do with questions about water depth and water temperature. There are ideal situations and there are situations that need to “be adapted to”. Everyone has his opinion, usually based on his experience and personal preference. For example, aquatic physical therapist looks at a pool much differently than a competitive swim coach, yet many times they have to share the facility because it’s the only pool available.


One of USA Swimming’s goals is to assist our clubs and the people who partner with our clubs in getting new pool water or making existing pools user friendly. This can mean renovating existing pools or building new multi-use facilities. One pool does not and can not meet every need of the aquatic community. Remember these two rules:

  • Never build a single use pool.
  • Programming precedes design.

You will hear the term TAD used throughout the industry. This stands for Temperature – Access – Depth.  All three need to be considered when programming a pool. You may have also heard the rule of thumb that the air temperature needs to be maintained within 2 degrees of the water temperature. This is only true within certain parameters. With the increasing popularity of warm-water rehab and specialty pools, this “rule” does not always apply. Air temperature higher than 85 degrees can be both unhealthy for the patrons and extremely hard on the building structure and equipment. More than air temperature needs to be considered.  he air flow CFM (Cubic Feet per Minute), humidity and mixture, if any, of outside air also are important. 

With all of this in mind we use the following guidelines for pool design:


Water Depth

Zero depth – Ramped entry – Beach entry
These are all terms for basically the same concept: the water starts at the dry land and gradually slopes to a comfortable standing depth. Sometimes this area can be as narrow as 40” and other times it can be as wide as the entire pool. Seldom is this the primary focus of the pool, usually it is a convenient form of entry into the pool. Zero depth pools have many uses.

  • Parent and baby exercise classes for ages birth through three years.
  • Swim lessons for small children. Having children stand in water that covers over 50% of their bodies during swim lessons allows children to develop their core strength. As their bodies become stronger they feel more secure.
  • Special needs children ages birth through three years, possibly in conjunction with the state’s Early Intervention Program. The zero depth is a wonderful place for the child to start learning to walk. Varying depths become an automatic way to measure the child’s progress.
  • Physical rehabilitation. Beginning in the deeper water and progressing towards shallower water the patient replaces buoyancy with gravity. Great for rehabbing ankles, knees, and backs! For diabetics, it’s just good to have the feet in the water to increase circulation.
  • Plyometric exercises. Varying depths allows a person to assess his or her improvement and control resistance.

Using different depths of water is a very valuable way to feel secure and measure one’s physical improvements. The temperature of the water will be determined by the primary use of the pool rather than it’s mode of entry. The temperature of the air should not exceed 84 degrees and can be much cooler depending on air circulation volume and zones.


Constant depth pools – (in ground or on ground.)  The uses are limited only by the imagination. On ground pools with raised decks and ramped access are increasingly popular.  Without some intricate design and construction modifications, these will all be constant depth pools.  As modular steel wall in ground pools become more economical to construct, constant depth will become the norm rather than the exception.  

The most common depth is 4’.  This allows reasonably safe diving into the pool while affording a very comfortable depth for both vertical water exercise and horizontal lap swimming.   Portable platforms can be put in the pool for swim lessons.  The same platforms can be used to decrease buoyancy and increase gravity for a variety of water exercises. 

Variable depth pools – The most challenging to design yet the most versatile.   No single pool can meet every aquatic need.  However, creative design coupled with multiple pools of varying depths and accesses can increase your ability to offer valuable aquatic services.  Many times two separate pools can fulfill most of the programming needs while three pools will generally cover it all.


Advantages of each depth

42” depth
Without a ramped entry, stair entry, or zero depth feature, most pools start with about 42” of depth at the shallowest end. 50% of the people who enter the water to do aquatic exercise or aquatic therapy do not know how to swim! Many have a fear of the water and are at risk as soon as they enter the pool. Great care and supervision must be provided.  In 42” water depth, a person who is 5’6” would be in water slightly above her waist. In deeper water there will be even less stress on the joints, but again, safety must be paramount.


Here are some appropriate uses of 42” water depth:

  • A walking program. The person will be at 50% weight bearing and yet feel reasonably safe while walking. 
  • A total body exercise program encompassing all of the 5 fitness components: aerobic, strength, flexibility, balance, and coordination.
  • An aqua suspended program designed by putting on buoyant equipment and working the aerobic system.  This will provide some strength training and trunk stabilization as well.
  • Aqua running, for the person who wants to train with resistance but with reduced gravity.
  • Aquatic mind and body exercises such as Ai Chi, Watsu, and Bad Ragaz. (Water temperature is a consideration for some of the mind and body exercises.)
  • Competitive swim training and lap swimming. Obviously NO DIVING or head first entries would be allowed!

Sloping to 48” depth
You can conduct all of the above programs and offer additional challenges by arranging the class to move across the pool. Place your participants by height. If you move the class the length of the pool it challenges the class by moving through different depths.


52” to 60” depth
52” to 60” water depth works well for the person who is comfortable in deeper water while still able to stand and for individuals who want to exercise with buoyant belts or flotation devices such as “noodles.”  This depth would be ideal for the extremely overweight person to reduce stress on his or her joints. Other uses include:

  • Water walking programs for people with orthopedic issues
  • Aerobic and strength training programs
  • Competitive swimming and health and wellness swimming
  • Vertical athletic training
  • Any usage for taller persons

7’ and deeper water depth:

  • The more aquatically advanced and skilled person. It is always recommended to have supportive devices such as belts or cuffs that allow a person to maintain proper posture and alignment.
  • The overweight person. These clients can be aerobically active with much less risk of injury than if in shallower water or on land.
  • Deep water “hanging” or vertical suspension. This therapy is very effective to decrease back pain. The person must be stabilized in a position to work the core muscles.
  • Competitive and fitness swimming.

Water Temperature
One of the most important features of facility design is the ability to vary water temperatures for specific populations and programs.  Many articles have been written on this subject.  Here are some general guidelines:


82 degree water (and lower)

  • Competitive swim team training
  • Adult aerobic lap swimming
  • High intensity vertical water exercise

Note: The ideal air temperature for these activities is 78-80 degrees; never higher than 82 degrees. The more aerobic the activity, the lower the air temperature needs to be.


86 – 88 degree water

  • Learn-to-swim
  • Moderate vertical water exercise and water walking
  • Younger age (10-under) swim training
  • Low intensity lap swimming
  • Synchronized swimming
  • Diving
  • Recreational swimming

Note: The ideal air temperature for these activities is 82-84 degrees; never higher than 84 degrees and slightly lower is OK.


90 – 92 degree water 

  • Aquatic therapy
  • AiChi
  • Learn-to-swim for children
  • Diving

Note: The ideal air temperature for these activities is 84 degrees; never higher than 84 degrees and slightly lower is OK.


95 degree water

  • Aquatic Therapy
  • Ai-Chi
  • Learn-to-swim for preschool

Note: The ideal air temperature for these activities is 84 degrees; never higher than 84 degrees and slightly lower is OK.


The Ideal Prototype
Are you looking for ideas for the “ideal facility on a budget”? Obviously this is an oversimplification, but here is a prototype: 


Main Pool

  • An 8 to 10 lane 25 yard pool
  • Water depth of 4 to 5 feet
  • 75 feet long by 67 feet wide
  • Stairs and railings (not ladders!) off to the side of the shallow end
  • Lane line anchor configuration to allow:
    • Eight 8’ wide lanes with extra buffered area on the outside lanes for competition
    • Nine 7’ wide lanes with slightly wider outside lanes for everyday swim training for “adult size” people
    • Ten 6.7’ wide lanes for age group swim training
  • Water temperature between 82 and 84 degrees depending on programming needs. Air temperature between 78-80 degrees.
  • In most geographic areas approximate construction cost of this pool, complete with basic operational equipment, would be $550,000.00 or less!

Community Pool

  • Four lane 20 yard pool
  • water depth 3’6” to 7’
  • 60 feet long by 36 feet wide
  • Railed 40” wide ramped entry along the side
  • Side stair entry at base of ramp 
  • Useable lane area is 32 feet wide 
  • The 7’ deep area is “hopper style” and takes up only 10’ of the length
  • The balance of the length is 42” deep gradually sloping to 52” deep
  • Water temperature between 87 and 89 degrees depending on programming needs. Air temperature between 82-84 degrees.
  • In most areas approximate construction cost of this pool, complete with basic operational equipment, would be $250,000.00 or less!

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