You may wish to assign mL of water use per household for each water use, or you may use the sample provided below. Students should record the amount of water left after each withdrawal. Have students devise a method to determine the maximum number of households the model watershed can support. Once the activity is complete, lead students into a discussion of water budgets. Ask them to revisit the Focus Question for the Everglades.
Humans also make withdrawals from the water account.
Although much of this water is recycled back into the system, only a small portion of water used in agriculture is returned to the account. When the account is overdrawn, humans rely on water supplies stored in aquifers. For the continental U.S., about 3.8 trillion gallons of water are credited to the water account annually through precipitation. South Florida's water budget differs from the national water budget. To highlight south Florida's unique water budget, refer students to the inflow and outflow pie charts in their Student Packets.