When are pressure regulating devices required according to MWELO?

The requirement for pressure regulating devices according to the Model Water Efficient Landscape Ordinance (MWELO) encompasses all system types, which includes sprays, rotors, and valves. This regulation is in place to ensure that water is applied efficiently and that the pressure levels within irrigation systems are optimal for the specific types of equipment being used.

By employing pressure regulation, the uniformity of water distribution improves, preventing overapplication and waste that can occur with excessive pressure. Additionally, it helps to protect the irrigation system components from damage and reduces the likelihood of excessive runoff or water loss to evaporation, both of which are crucial in promoting water conservation strategies mandated by MWELO.

The incorrect options highlight situations where regulatory requirements may not be universally applicable, such as limiting the rules to only residential systems or specific types of water sources like recycled water. This comprehensive approach in option B underlines the importance of maintaining water efficiency standards across all landscaping scenarios, reinforcing the broader goals of water conservation reflected in MWELO.