|
Test Irrigation System
Lawns
To determine system application rates in turf areas, follow these instructions. Perform one test for each valve with a different type of irrigation sprinkler head.
| 1. | Use 12-20 flat-bottomed containers with sides at a 90° angle to the bottom. Empty tuna fish cans work well. Place containers at least 18” to the inside of each sprinkler head. Form a grid by placing another can midway between sprinklers (also 18” to the inside). Turn the irrigation station on for 15 minutes. |
| 2. | Measure the depth of water in each container with a ruler. Total the measurements, then divide that number by the number of containers in the grid. This will determine the average water depth in the containers. |
| 3. | Multiply this average depth by 4. You now have the application rate of that station in inches per hour. |
| 4. | Go to the scheduling charts. |
| 5. | Select the proper water-use chart for soil type and plant material. |
| 6. | The first column is titled A.R. (Application Rate). Use this column to find the number closest to the application rate found in Step 4. For very low application rates, average a cycle time by using the application rate on the chart above and below the tested rate. |
| 7. | Now read across the column to determine the cycle duration (minutes per cycle), number of start times (cycles per day), and number of watering days for the current month. |
Shrub Areas, Flowerbeds and Gardens
Perform one test for each type of irrigation system by reading the water meter and measuring the watered area. The numbers around the edge of the water meter face are either whole numbers (.1, 2, 3) or in tenths (1, .2, .3; or 1/10, 2/10, 3/10).
To determine system application rates in shrub areas, follow these instructions:
| 1. | Turn on the irrigation station to determine the area the water covers. |
| 2. | Wait until there is no sound of air rushing out of the nozzles. Using a stopwatch, or timepiece with a minute hand, determine how long it takes for the sweep hand on the water meter to make one full revolution. Record this time. |
| 3. | Determine area by measuring the entire planted section and any over sprayed areas. (Over sprayed areas are anywhere that gets wet when the sprinklers are on – including sidewalks, patios and porches.) Using the calculation: Length X Width = Area is the easiest way to determine an area’s square footage. Most areas can be squared off so that this calculation can be used. Others require dividing the area into smaller squares, calculating each square footage, then adding them all together for the total area covered by that station. |
| 4. | Calculate the application rate (AR) by using the formula: 720 X Volume/Time /Area = AR (“/hr.) or 720 times Volume divided by Time divided by Area = inches per hr. |
| • | 720 is a constant, converting feet to inches and minutes to hours |
| • | Volume will be 10 for meters reading in whole numbers and 1 for meters reading in tenths. |
| • | Time should be written in minutes, with seconds converted to parts of minutes; i.e., 1 minute, 20 seconds/60 = 1.33 minutes |
|
