Simplify the following text for a Grade 7 native English-speaking person.
Original: The ancient falaj system of irrigation is still in use in some areas ; this system distributes underground water by a network of tunnels which emerge eventually into open channels whose flow can be directed and regulated .
Simplified: The ancient falaj system of irrigation is still in use in some areas . The system brings underground water to people by a network of tunnels that come out into open channels .