Water Levels are very simple to understand and operate. Since water seeks its own elevation, a water level allows you to set a datum or known elevation to work from. If you want to know how to build a water level, keep reading. Once your water level has found a level reference, or datum, you can then measure up or down from there to set "level" across multiple known points. Water levels work great for only a few set ups and minor distances like 10 to 50 feet or so. Anything over 50 feet we recommend an Auto Level, Transit Level, or Laser Level.