Niagara Falls: Border-Straddling, Surface-Water Fed, Not Groundwater

Water Source: The Great Lakes Superhighway

1. Lake Superior → St. Marys River → Lake Huron
2. Lake Huron → St. Clair River → Lake St. Clair → Detroit River → Lake Erie
3. Lake Erie → **Niagara River** (58 km / 36 mi) → **Niagara Falls**

• Flow: 5,700 m³/s (200,000 cfs) average — 25% diverted for hydro
• Travel time: ~200 years for a water molecule from Superior to Falls
• Zero groundwater contribution at the falls — it's all lake outflow

Border Geography

• Horseshoe Falls (90% flow): Mostly in **Canada (Ontario)** — but border cuts through it
• American Falls + Bridal Veil Falls (10% flow): Entirely in **USA (New York)**
• Goat Island: Splits the river — US territory
• Boundary: 1908 treaty defined line; 1950 remedial works adjusted

Why Not Groundwater?

• Great Lakes = **glacial meltwater + precipitation** — surface origin
• Niagara River = **surface outflow** from Lake Erie
• Groundwater = **subsurface flow in aquifers** — contributes to lake levels indirectly, but not the river's direct flow
• Falls = **erosional knickpoint** cutting back through Lockport Dolomite caprock

Human Engineering

• 1950 Treaty: Minimum flow 100,000 cfs (day), 50,000 cfs (night) over falls
• Robert Moses / Sir Adam Beck plants: Divert 50–75% flow for power
• 1969 Dewatering: American Falls stopped 5 months — rock talus study

Niagara is a **binational, surface-water, treaty-managed, hydroelectric-engineered** wonder. Groundwater? Not in the equation.