What percentage of large installations must be audited according to MWELO?

The correct percentage for auditing large installations according to the Model Water Efficient Landscape Ordinance (MWELO) is indeed 15%. This requirement is in place to ensure that landscape projects comply with established water efficiency standards.

Auditing is a critical component because it guarantees that the installations adhere to the designs and water usage regulations initially set forth. The chosen 15% threshold strikes a balance between ensuring compliance across large installations while being manageable for oversight. This percentage reflects a commitment to promoting water conservation and responsible landscape management, essential in California, particularly given the state's ongoing challenges with water scarcity.

The other options, while numerical possibilities, do not align with the specific legislative requirements outlined in MWELO for large landscape installations. The intent behind setting a percentage is to create an actionable and enforceable guideline that can be monitored effectively, which is why this particular figure has been established.