Attached are provisions of the Calif. Water Code (Sections 13550 – 13554) which states that using potable water for certain nonpotable purposes, including cemeteries, golf courses, parks, highway landscaped areas, and industrial and irrigation [of residential landscaping] uses; including toilet and urinal flushing; “if suitable recycled water is available… is a waste or an unreasonable use of the water… if recycled water is available which meets all of a list of certain conditions”, ie, adequate quality, reasonable cost, not detrimental to public health, etc.
This section may be useful in trying to get more purple plumbing to new subdivisions, parks, etc. It does not specifically apply for agric. irrigation purposes.
Or, then again, it might be a reason for certain cities and agencies to drag their feet in getting purple plumbing anywhere near new developments, if they don’t want to ‘force’ developers to dual plumb the new construction.