CA Gov't Code Section 50062.5

If a district established pursuant to this article levies an assessment under this article to maintain or improve natural habitat, any lot or parcel is presumed to specifically benefit from the natural habitat if one or all of the following occur:

(a)

The past or proposed development or use of that lot or parcel has adversely affected or will adversely affect the habitat area or the flora and fauna which the natural habitat is intended to protect, and the extent to which a parcel benefits from the natural habitat shall be based on the degree to which the past or proposed use of the parcel has adversely affected or will adversely affect the habitat area or the flora or fauna that the natural habitat is intended to protect.

(b)

The lot or parcel otherwise benefits from the maintenance or improvement of the habitat area or the flora or fauna that the natural habitat is intended to protect.