If the notice to abate is recorded before the commissioner incurs the expense of abatement, the amount which is incurred or expended by the county in the abatement is a lien on the land against which the expense is chargeable. In a case pursuant to Section 5494, the total expense shall be prorated and chargeable against each parcel of land in proportion to the acreage of such parcel which is served by water from the canal or ditch that is involved.