What is the formula used to calculate the Precipitation Rate (PR)?

The correct formula for calculating the Precipitation Rate (PR) is derived from the relationship between the amount of water applied by a system and the area over which it is applied. In this case, the equation PR = (96.25 x Total GPM) / Hydrozone area provides the necessary calculations to derive the precipitation rate measured in inches per hour.

This formula effectively shows that to determine the rate at which precipitation occurs (in inches per hour), you must account for the total gallons per minute (GPM) being delivered and the specific area of the hydrozone where the water is applied. The value of 96.25 serves as a conversion factor that relates GPM to a precipitation rate in a more usable format for landscape architects, facilitating the design and analysis of irrigation systems.

Using this formula allows professionals to ensure that their irrigation designs provide adequate water coverage for plant health while also maintaining efficiency, which is key in California's varied climate conditions. This is particularly important for landscape architects who are often tasked with managing water resources effectively.