Tool T04 · Water Budget

Can the aquifer keep up?

Every day, water enters the Memphis Sand Aquifer (recharge, leakage) and leaves it (pumping, discharge to rivers). When outflows exceed inflows, the aquifer depletes. Play with the dials. Find where the balance tips.

Daily balance

+3 MGD

Roughly balanced

Annual

1095 MG/yr

−100%balanced+100%

↓Recharge IN

240 MGD

From rainfall in recharge zone

↑Pumping OUT

200 MGD

MLGW + industrial + agricultural

↑Baseflow OUT

75 MGD

Discharge to rivers + streams

↕From shallow aquifer

38 MGD

Leakage through UCCU breaches (+ in, − out)

Budget breakdown (MGD)

Inflows

+278

Outflows

−275

What the numbers mean

MGD = million gallons per day. MLGW withdraws about 200 MGD. The natural recharge from the recharge zone is estimated at 240 MGD, with additional leakage through breaches bringing total inflows close to 280 MGD.

Historically, before heavy pumping, most of that recharge discharged as baseflow to streams like the Loosahatchie and Wolf rivers. Today, heavy pumping intercepts much of that flow — which is why those rivers' baseflow has dropped over the past century.

Data:CAESER MLGW Study (2023)·USGS MERAS·MLGW