Terracon provides aquatic design and swimming pool engineering services for public use, recreation, and competition swimming pools that include colleges, universities, high schools, municipal community pools, resort facilities, above-grade and in-ground hospitality pools, lazy rivers, splash pads, and a variety of water features, fountains, and water elements.

Terracon has become a proven leader in aquatic design and engineering with many years of experience and has designed more than 630 commercial swimming facilities for both publicly funded and private entities.

Terracon is fully committed to the advancement and betterment of the swimming pool construction industry. Additionally, company engineers have provided expert witness testimony in litigation for deficient swimming pool structures, published several articles in national aquatic publications, and are regular guest lecturers at swimming pool and spa pool construction industry conferences and trade shows throughout the U.S.

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Select the Months you plan on heating your pool:

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec


This program utilizes published equations of thermodynamics to compute and chart two major characteristics of an operating outdoor pool, which are:

  1. The average monthly water temperature of a non-heated pool
  2. The monthly cost of heating a pool to a specified water temperature

The computed costs are for heating only and do not include the cost of running circulation pumps and other equipment. The primary benefit of this program is the ability to compare the cost benefits of various energy saving features which can be added to a pool.

The following steps will gather weather data for your location, pool dimensions, if the pool is heated, and what energy saving features you want to include in your design.

Please click begin to start

Step 1 - Choose Location


Water temperature and heat transfer are highly dependent on local weather conditions (temperature, wind, humidity, and solar radiance). This program utilizes 30 year average weather data from the National Climate Data Center (NCDC) data base for major cities throughout the United States.

You should select the closest city to your location, or a city that closely represents the typical weather of your location. Average weather parameters for the selected city are displayed in a chart at the bottom of the results. If a detailed site-specific analysis is desired please contact us.

Step 2 - Pool Dimensions

Input the approximate dimensions of your pool. The most critical number here is the surface area of the pool. Water features extending beyond the footprint of the pool which are only operated periodically may be ignored. However, if water features are to be operated on a regular basis their estimated exposed water surface area should be added to the total surface area of the pool. Where a feature utilizes falling water, its estimated surface area should be doubled to account for both exposed sides of the water.
Pool Surface Area (sq.ft)
Pool Perimeter (ft)
Average Depth (ft)

Step 3 - Heated or Non-Heated? Non-Heated Selected

heated pool

Choose one of the following two conditions to determine either the monthly water temperature or monthly heating costs:

  1. Non-Heated Pool - Program will compute the average monthly pool water temperature and number of "swimmable" days for a user specified minimum swim temperature. Enter the desired minimum water temperature.
  2. Heated Pool - Program will compute the average monthly heating cost to maintain a user specified minimum water temperature. Enter the desired water temperature and select the type of heater to be used. You must also enter the local cost of the appropriate form of energy the heater will use; natural gas, propane, or electricity. The most recent utility bill or delivery invoice should have the unit cost of energy.

Select your pool type:

Desired Water Temperature (F)
Heater Type
Cost per Therm ($) ?
Heater Efficiency ?
Cost per Gallon ($)
C.O.P. ?
Cost per kWh ($)
Select Heating Season Months
Swim Season Water Temperature (F) ?

Step 4 - Select Energy Saving Features

For any conditions selected in the previous three (3) Steps you can specify any number of energy saving features and track their individual or combined effect on water temperature and/or heating costs. The program will chart a history of each set of input parameters. It is a good idea to start by selecting no features and then add them one at a time so that you can compare temperature and/or cost savings of each.

Pool Cover

Pool covers offer the greatest energy savings and swim season lengths. It is important to cover your pool when not in use. Select below to add a cover and also select the type of cover you will be using.

Solar Heater

Roof mount solar collector which heats your pool

Solar collector area (sq. ft)
Solar Heater Efficiency

Wind BreakAdded

If the pool is located in an urban setting with surrounding homes, fences and trees, then a wind break is assumed by default. However, if the pool is in a rural setting or surrounded by a large open area, then please click "Remove Wind Break".


If your pool is shaded you will lose some solar radiation gains.

Percent of the pool that is shaded. (%)

Insulated Shell

A finite analysis program was used to estimate heat loss into the surrounding soil. Initially the amount may not seem significant when compared to losses off the surface; however, when other energy saving features are utilized such as a cover, the percent of potential savings becomes more significant. Generalized values have been used in this program. If a more site specific analysis is desired or for ideas on ways to insulate a shell, please contact our office.

Results History for Non-Heated Pool
Run NumberSet Pool Temp (F)Swim Season Length (days)Options

Monthly Water Temperature (F)

Results History for Heated Pool
Run NumberSet Pool Temp (F)Est. Annual Heating CostOptions

Monthly Heating Costs

Weather Data for Location (Yearly Average)
SeasonAverage Temperature (F)Humidity (%)Wind Speed (MPH)Solar Radiation (W/m^2)


Aquatic Design

  • Existing Aquatic Facility Evaluation: For making informed decisions regarding options for the purpose of extending or enhancing the life and revenue stream of an existing facility.
  • Renovation: Rehabilitation with geotechnical engineering knowledge to provide structural shell engineering solutions to pool shell failures and for rehabilitation upgrades.
  • Distressed Facility (Diagnostic) Evaluation: Completed by experienced and licensed structural, geotechnical, and materials engineers on staff to determine and provide appropriate recommendations for remediation/repair.
  • Programming and Concept Design: Planning swimming pool facilities for both recreational and competitive use, to evaluate the site for aquatic design, programming and master planning.
  • Design Services: Including recirculation, filtration, sanitization, structural engineering of the pool shell, and electrical engineering.
  • Construction Observation: In coordination with many regional, state, and national swimming pool contractors and fully understand the swimming pool construction process, techniques, and schedule implications. We use our aquatic engineering knowledge to foresee unexpected problems with an attempt to navigate past them before costly errors can occur.

Swimming Pool Clients and Services

  • Municipal and community centers
  • YMCAs
  • high school districts
  • colleges and universities
  • community sports and wellness facilities
  • resorts, lodges, casinos and hotels
  • special inspections and material testing
  • forensic studies and investigations
  • remedial design solutions
  • energy analysis and retrofit
  • expert testimony


For more information about aquatic design and swimming pool structural engineering, please contact the following:

Matthew Reynolds, P.E.
Concord, CA
(925) 348 9059

Matt Cappello, P.E.
St. Louis, MO
(314) 692 5592

Travis Stensby
Dallas, TX
(925) 222 3005