CRC_SlowTheFlowPhase1_FinalReport

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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . the water distributed. Poor uniformity results in overwatering as the watering time is extended for an entire zone in order to apply sufficient water on an area that it is not receiving as much water compared to other areas of the zone. Such problems are relatively easy to fix and greatly improve the efficiency of a zone when repaired. . Replace irrigation heads within a zone so that all heads are of the same type (i.e. fixed, rotor, or drip-type). Rotor and spray heads are designed to apply different water at different rates and are inefficient when used together. . Replace turf, where appropriate, with hardscape or water-conserving plants. Perform Catch Cup Tests: Catch cup tests are performed on designated zones. A catch cup test utilizes calibrated cups, set in a grid pattern on the landscape, to collect water from an irrigation system. The amount of water collected can be used to determine distribution uniformity and precipitation rates. Distribution uniformity (DU) is a measurement of an irrigation system's ability to apply water uniformly over the surface of a landscape and directly influences the amount of water required to keep the landscape green. Since the amount of water put out by an irrigation system is not completely uniform, some parts of the landscape will receive more water than others. Efficient systems operate at a DU of 70% or greater and minor adjustments to most systems can improve the DU. Precipitation rate (PRY is the amount of water emitted from an irrigation system measured in inches of water per hour. Different head types have different precipitation rates. The precipitation rate determines how long a sprinkler system needs to run. A spray head usually emmits 1-2 " (on average 1.4") of water per hour while a rotor head emmits .5 - 1 " (on average .9") of water per hour. It is typical to see PR's that vary greatly between manufacturers. It is crucial to match precipitation rates of each rotor head within a zone to avoid over or under watering. Quarter-turn heads should emit half the amount of water as half-circle heads. Likewise, a full-circle head should emit double the amount of water as a half-circle head. For example, if the comer heads in a square area deliver 2 gallons of water per minute, the heads along the edges of the square should deliver 4 gallons of water per minute, and the full head in the center should deliver 8 gallons of water per minute. If all heads are delivering the same volume of water, the center area won't receive enough water while the comers will receive an excess, resulting in a low DU. Take Pressure Readings: Pressure readings are taken on spray zones, and when possible rotor zones. The design of rotor heads makes it difficult to accurately check the pressure. The proper pressure for fixed heads is between 20 and 30 pounds per square inch (PSI); proper pressure for rotor heads is between 50 and 70 PSI. The proper pressure will vary between brand names. Recommendations are given to adjust pressure to conform to optimum standards by installing pressure regulators at the point of connection, valve box, or at each sprinkler head. High pressure causes misting and evaporation, and can cause heads to break. Low pressure can cause low distribution uniformity depending on how far apart heads are spaced. Determine Soil Type and Root Depth: A soil sample is collected to determine soil type and root depth. Soil type is categorized as clay, sand, loam or some combination thereof. Soil type can affect the 3