Ultrasonic Water Flow meter for remote locations.

Dear All: The environmental authority in my country requires that every water capture for private use should be equipped with a water meter, whether ultrasonic, or electromagnetic. These captures are in very remote areas, with no energy or internet connection availability. These water meters should store the data of the flow in a way that can be collected every month, or even less frequently, and therefore, they must be equipped with a long life battery.

Can you refer me to a manufacturer of such products?