Dealing With a System Where Water Pressures Aren't Quite as High as They Used to Be

Several years ago a moderately-sized city park opened in a relatively new suburban area where, at the time, there was just a handful of surrounding development. To irrigate the wide expanses of turf, the park's landscape manager installed rotary sprinklers with square spacing at 62 feet from head to head. The flow was in the range of 24 gpm per head and the head operating pressure was approximately 80 psi (if you're itemizing all this, that last fact is the one of which you'll want to take particular note).

The system worked well until increased development in the area began to tax its infrastructure. Water pressures (remember, they had been 80 psi) dropped to a point that the irrigation system no longer performed in the way it was originally designed or installed. The heads were now running at about 50 psi, there was no longer head-to-head coverage and the result was that turf quality was suffering.

At first, the landscape manager figured the heads were at fault. But, then he realized that the rotors were performing the best they could at considerably lower pressure. He then figured he would have to install a booster pump at the site to increase pressure to a level needed for proper system operation. Of course, that would also incur the expense of a small pump house, electrical service, pump start relay and labor that would be well beyond what the city had in its budget.

With the aid of his Hunter sales rep, a more effective (better performing) and more efficient (less expensive) solution was reached: the old rotors would be replaced by Hunter I-60s. A large turf rotor with superior water distribution, a small exposed body cap diameter and the ease of adjustment for which all Hunter rotors are famous, the I-60 has been designed especially for systems that deal with both lower pressures and smaller budgets.

A crew of three was able to perform the retrofit in less than a day. They were able to use existing piping and head spacing and, with #20 nozzles, wound up with perfect coverage. The extra expense of purchasing and installing an entire booster pump system was avoided and no alteration to the existing system layout was required. And, once again, less was more – with the I-60, less time, less money and less hassle resulted in a system that was more efficient.