Some of the more critical concerns in designing sprinkler systems for slopes are less of a problem for drip systems. Run-off and erosion for instance are less likely at the low flows produced by emitters. However, as mentioned earlier, changes in pressure because of changes in elevation do effect drip systems. Because emitters operate at low pressure, elevation pressure changes can create significant variations in their discharge rates.
When supplying water for a drip mainline or lateral line from the bottom of a slope, multiply the vertical elevation rise in feet by .433 to obtain the pressure (in PSI) needed to overcome the Elevation loss .when supplying water from the top of the slope a pressure gain will occur at the same .433 PSI per foot of elevation drop. (See the example)
To control pressure variations due to elevation changes, run the mainline up or down the slope with valves and pressure regulators to reduce the pressure entering the drip laterals. Group emitters that are at or near the same elevation together on the same valve and lateral.
Emitter Placement On Slopes
Because of a slight downhill flow prior to entering the soil the water may form a wetted pattern away from the plant root zone.
Placement of the emitter above the plant material avoids this problem.