Recently the new Institute of Behavioral Science Building was constructed in the Grandview area of campus. During construction, they ran into some schedule challenges-passing the October 1 planting deadline-which prevented us from landscaping. Now that spring is here, we have finally gotten to the point of landscaping the building. The tenants are very excited considering they have had to look at a baron dirt only landscape all winter long.
One of the major design criteria of this building was working to an extremely xeric landscape using almost exclusively a product called Netafim. Recently, this type of drip irrigation-water is emitted through the tubes themselves-is being used over traditional drip tubing-a very small tube is run to each individual plant. However, there are some challenges with this application method. The orifices in the tubes are very small and if you dont make sure to have pre-filters on the irrigation valves these holes will get clogged. The major downside to this is if you are not watching the plant material closely, or inspecting the pipes for operation, you won't know that they aren't working until the plant starts to wilt.
With only three irrigation technicians to monitor the entire university irrigation system; this can be a difficult challenge. One way we have found to help give a visible notification that the drip line is working is a small pop up sprinkler head on the end of the line. This sprinkler head has a nozzle on it that is closed and does not emit water but will still pop up just like a normal pop up sprinkler. By looking for these sprinklers we are able to know whether the line is working without having to spend time pulling the mulch and weed guard to verify operation.
The upside to this type of irrigation is the prevention of evaporative loss and control of the pattern of irrigation. A major downside of spray types of irrigation is making sure the heads are operating properly so that the water is being put on the landscape and not onto concrete or other hardscapes. With this type of application we are also able to mitigate drift from external forces such as wind. Since the irrigation is applied under a weed barrier and under 4" of mulch it is a very directed application, the proper amount of water directed exactly to the proper location.