"Avoid excessive water use which allows surplus to run to waste, including the use of drinking water for washing buildings, structures, driveways, patios, parking lots, tennis courts, or other hard surfaced areas, except in cases where health or safety are at risk.All non-residential water users within the District, must have low-flow showerheads and faucet aerators (2.5 gallons per minute), and al" . . . . . . .