Typically, golf courses close during the maintenance week, and we have to say that it is a perfect time to perform an irrigation audit. Not only because disturbance to members or visitors is avoided, but also because laborious tests such as the ones to determine the distribution uniformity, can be performed very efficiently.
So that, we visited the Real Club de Golf Las Brisas in June to perform an irrigation audit while the course was closed for play. On this occasion, the audit targeted irrigation efficiency.
The importance of irrigation pressure distribution and the pump station
The golf course orography and the irrigation system design at Las Brisas, make pressure distribution a vital aspect of it. The pump station is located in the lowest area of the course and pressurizes the system from there. An optimized irrigation software configuration and the possibility of working with a long irrigation window, aid improving pressure distribution in the system. However, it is key to determine the pumps´ optimum duty points and assess their hydraulic efficiency to improve the situation.
Bearing this on mind, the audit focused on the following 3 points:
– A performance test of the pumps and an assessment of their duty points.
– The calculation of the system pressure operation point to guarantee an adequate performance of all the sprinklers.
– An inspection of all the existing pump security and control devices.
Evaluating irrigation distribution uniformity
The audit included evaluating the irrigation uniformity of the “back-to-back” sprinkler system in greens (both for “green in” and “green out” sprinklers) as well as in tees, where there is a complementary and “independent” block system design for the tee boxes. The aim of this evaluation was to determine the best possible nozzle configuration of the sprinklers to achieve the highest possible distribution uniformity.
This nozzle fine-tunning was vital for greens, due to differences in spacings and the need to irrigate independently areas with different irrigation requirements (bentgrass / bermudagrass).
In addition to the general irrigation system that covers all playing areas, there is an independent and complementary network for the bentgrass tee boxes, that consists of a block irrigation system. For these areas, we undertook a precise study of the nozzle configuration too, in order to determine the best possible configuration, paying attention to the overlapping between sprinklers.
After performing the distribution irrigation tests, we modelled the performance of the sprinklers of various nozzle configurations, using the irrigation analytical software SPACE. This allowed us to identify the points that had room for improvement. So that, and as part of the audit final report, the recommendations included a detailed list of recommendations regarding changes in sprinkler nozzle configuration. This will lead to achieve the best possible irrigation distribution uniformity (DU), and offering consistent playing surfaces.
Irrigation strategy on greens
Finally, we carried out various irrigation tests to assess the performance of the selected sprinkler nozzle configuration on greens. The main aim of these tests was to compare results between the 360º-180º vs 180º-180º options. In this case, we evaluated uniformity, precipitation in bunkers, overlapping, sprinkler operation times, cycles and soak times for flushing, and required maintenance associated costs (adjustment of arcs in part-circle sprinklers).
Also, and due to the particularities of this course, we analysed the pros and cons of deep and infrequent irrigation vs. light and frequent irrigation, providing the Club with the objective dato to make the best decisions.