MP rotators can save water in several ways:
- Low water pressure at far end of pipe run from valve.
- Spray heads spaced too far apart.
- Atomization of spray from high pressures, especially near valves.
- Run-off from clay soil not being able to absorb the high precipitation rates of Rainbird heads.
All of these produce uneven watering. Uneven watering causes you to increase overall watering levels to eliminate the brown spots, but this results in overwatering of the areas that are not brown. By making the distrubiton of water more uniform, the tendency to "overwater" to compensate for dry spots is significantly reduced.
MP heads have 1/5 the precipitation rate of comparible Rainbird spray heads. If an original irrigation system has additional heads added to extend the area irrigated, then the line diameter may be inadequate for supplying this total volume of water without a significant pressure drop. A low pressure at the far end of the line will reduce both the precipitation rate AND the radius throw of the spray heads furthest from the valve causing less watering and dry spots.
MP rotators solve both of these problems by reducing the total flow of water through the pipes, eliminating pressure drop problems. Also, the available of MP radius up to 28' allows the correction of spray heads that have been placed too far apart for optimal overlap without the costly expense of re-piping to a larger diameter or re-positioning/adding spray heads.
Finally, since MP rotators have larger droplets of water, they are less likely to atomize the water causing loss of water to evaporation and wind. They also eliminate the need to run the valve pressures high to over compensate for the pressure loss created in an undersized pipe. Pressures can be lowered, and are more uniform, eliminating the atomization.
High precipitation rates can cause run-off and wasted water if the soil cannot absorb it as fast as it is being delivered. Just look at your current system, and you will be able to see if runoff is occurring near the end of the watering period.