Soil Infiltration Rate Chart
Use this chart to determine how much you can water at one time. The numbers are Inches Per Hour.
The first thing to know is that in DFW we have clay soil. The infiltration rate for clay soil is 0.13 inches of water per hour on flat ground. On a 12% slope that decreases to 0.05 inches of water per hour. To put that in perspective a 45° slope is a 100% slope, a 10% slope is 5.71°.
Clay soil has the greatest horizontal movement of water of all soil types.
This means watering for 10+ minutes is a waste of water because our clay soil simply cannot accept it. Even if you have flat ground, the water will sit on top. Which results in mosquitos and weed patches, not green grass.
The key takeaway is not to water once a day for long time. Water multiple times per day for short bursts. Smart timers have Cycle and Soak programs we can set up. We will program each zone to run for 2-6 minutes multiple times a day. The time is based off our slope and precipitation rate calculations. As well as how many days per week you’re allowed to water.
For clients on watering restrictions, we have set systems to run up to 7 times per day for no more than 4 minutes at a time. This ensures there is no run off, and more importantly it doesn’t cost any additional money. Often, once the grass starts looking better we can dial the watering back.
(Chart and graph below)