The Watershed Atlas · Compare
Six watersheds, one honest question: when the same storm falls today as fell in 1985, how much more of it runs off — instead of soaking in? Press play and watch our ground harden. Every number here is modeled from public federal data.
A hollow ring marks where each watershed stood in 1985; the line behind each dot is 38 years of hardening. “Ordinary storm” = the coin-flip kind — about 3.8 inches, roughly 50-50 odds in any given year.
California Branch runs off the most here — but for a different reason: its flat, wet Coastal-Plain soils were never a good sponge to begin with. Pavement is the Piedmont story; soggy ground is a different problem. See its page →
Two points sounds like nothing. It isn't — the scale isn't linear, and every point sheds more water than the last. Anchor values are standard engineering figures for local soils.
One catch on the gallons: they track a watershed's size as much as its pavement. Reedy and Eighteenmile lead on total gallons because they're the biggest — acre for acre, the small campus creeks are the flashiest of all.
The highest-leverage fix on the map
It's easy to look past Golden — it's tiny, near Easley, and its runoff numbers are the smallest here. That's exactly why it matters. Golden is already twice as paved as Lower Eighteenmile and past the line where streams start to degrade — but it's small and steep enough that a single well-placed regional detention basin could hold back a real share of what it sheds. This is where a dollar of intervention buys the most watershed.
Catch it here, and you protect everything downstream in the Lake Hartwell system. Wait, and Golden becomes the next Hunnicutt — where the only fix left is undoing pavement.
55 gallons — the first rinse off a roof. How a household joins in.
A parking-space-sized garden, dug 6 inches down, holds ~500 gallons — the first inch of rain, the one carrying the oil and fertilizer.
One acre holding one foot of water stores 326,000 gallons — an acre-foot, the same unit as the damage.
The fix is measured in acres, not miracles. Here's the wetland/floodplain acreage that would hold back each watershed's entire extra runoff from an ordinary storm — often about 1% of the land:
| Reedy River | 331 acres |
| Lower Eighteenmile Creek | 90 acres |
| Hunnicutt Creek | 22 acres |
| Berkeley Creek | 22 acres |
| California Branch | 10 acres |
| Golden Creek | 6 acres |
Want a rain garden on your block, or a basin on your creek? That's the kind of thing a neighborhood can actually push for — and figuring out where it goes is exactly what we do. Come talk to us.
These six watersheds are the wide view — how much rain the land sheds. Zoom all the way in and you can read the result in the streambank itself: a channel cutting deeper, banks pulling apart, a bed filling with the sediment the runoff carried. That's the companion atlas.