3. Any withdrawal in existence on July 1, 1989, from an instream impoundment of water used for public water supply purposes; however, during periods when permit conditions in a surface water management area are in force under regulations adopted by the Board pursuant to § 62.1-249, and when the rate of flow of natural surface water into the impoundment is equal to or less than the average flow of natural surface water at that location, the Board may require the release of water from the impoundment at a rate not exceeding the existing rate of flow of natural surface water into the impoundment. Withdrawals by a political subdivision or investor-owned water company permitted by the Department of Health shall be affected by subdivision 3 of subsection B only at the option of that political subdivision or investor-owned water company.
To qualify for any exemption in subsection B of this section, the political subdivision making the withdrawal, or the political subdivision served by an authority making the withdrawal, shall have instituted a water conservation program approved by the Board which includes:
(i) use of water saving plumbing fixtures in new and renovated plumbing as provided under the Uniform Statewide Building Code;(ii) a water loss reduction program;(iii) a water use education program; and(iv) ordinances prohibiting waste of water generally and providing for mandatory water use restrictions, with penalties, during water shortage emergencies. The Board shall review all such water conservation programs to ensure compliance with (i) through (iv) of this paragraph.