Water supply & consumptive use

The screen above sets the modeled draw against the Ottawa River’s cited 7Q10. That is the drought floor a permit writer screens every discharge against. But Lima’s water does not come out of the river in real time. Read the comparison as a bound, not as a withdrawal claim.

The city holds its raw water in 5 upground reservoirs, off the river channel. Together they store about 14.4 billion gallons. Of that, 10.1 billion is filled from the Auglaize River to the west and 4.3 billion from the Ottawa to the east. Four pump stations fill them, and run only when the rivers are high. Lima therefore never withdraws at the 7Q10. It lives off stored water.

That changes the question this chapter must answer. The binding constraint is not what the river holds on its worst day. It is how far the campus draws the reservoirs down across a dry season, and whether the rivers can refill them afterward.

The number that survives the reframe

The campus buys treated municipal water like any other large customer. Its modeled makeup^input of 3.92 million gallons per day (MGD) is 20.7 % of the 18.92 MGD the plant would then produce. The plant makes about 15 MGD today and is rated for 30 MGD. One customer would take a fifth of the city’s water production.

The consumptive part is harder still. About 3.14 MGD leaves as water vapor from the cooling towers and never returns to the basin. What does return goes downstream to the Ottawa through the treatment plants^rec . None of it goes back into the reservoirs, so the full makeup draws storage down.

Run that against the stored volume and the zero-refill drought reserve falls from 960.9 days to 761.8 days. The campus costs the city 199.1 days of drought reserve.