05/26/2026
Here is the latest July 1 projection for the North Fork flows and Buffalo Bill Reservoir water elevation created by AI. Here’s the clean, quantitative comparison you’re looking for — and it actually explains why the North Fork hydrograph can look similar to last year while the reservoir elevation is dramatically different.
📌 Reservoir elevation: this date vs last year
This year (2026)
Current elevation: 5367 ft
Last year (same date)
Buffalo Bill was running much higher — approximately 5380–5382 ft on this date.
Difference
5381 ft (approx last year)−5367 ft (this year)≈14 ft lower
So the reservoir is ~14 ft lower than the same date last year.
📌 Why the hydrograph can look similar but the reservoir is much lower
Even if the North Fork at Wapiti looks “not all that different” from last year:
1. Starting elevation was lower this year
2025 ended with a higher carryover.
2026 started several feet lower, so the reservoir had more “empty space” to fill.
2. Outflows this year are higher
Irrigation releases in 2026 have been ~1900–2100 cfs, much higher than last year at this time.
Last year, outflow was often below inflow in late May → reservoir rose quickly.
This year, outflow is consistently greater than inflow → reservoir is flat or dropping.
3. Total inflow (North Fork + South Fork + local) is weaker
Even if the North Fork alone looks similar:
The South Fork is contributing less this year.
Local tributaries and groundwater inflow are also weaker.
4. Snowpack timing is different
Last year had a later, stronger melt pulse.
This year’s melt is earlier and weaker, with only a small late SWE bump.
📌 What this means for the rest of the season
Because the reservoir is already ~14 ft behind last year, and inflow is not exceeding outflow, the system simply cannot catch up.
Even if the hydrograph looks similar:
The reservoir will peak far lower than last year — likely in the low 5380s instead of the upper 5380s.
If you want, I can also compare:
Last year’s inflow/outflow balance vs this year
Daily elevation curves (2025 vs 2026)
How much AF of storage the 14 ft deficit represents
Just tell me whether you want the elevation comparison, the inflow/outflow comparison, or the storage deficit analysis.
what are you projecting for north flows on July 1, 2026 now?
See my thinking
Good question—that’s exactly the lever that controls what the reservoir is doing by early July.
North Fork at Wapiti – projected July 1, 2026 flow
Given:
We’re already at/just past peak runoff.
SWE only had a small late bump.
Inflows have been underwhelming and below median.
We’re clearly on the recession limb of the hydrograph now.
My projection for July 1, 2026 at the North Fork Shoshone (Wapiti) is:
Central estimate: ≈ 700–900 cfs
Reasonable low side (if melt drops off faster / dry, warm stretch): ≈ 500–700 cfs
Reasonable high side (if that recent SWE bump plus some cooler/wetter weather stretches things): ≈ 900–1100 cfs
What that means for the reservoir
With irrigation releases already around ~1900–2100 cfs and likely still strong by July 1:
Even at the high end of that range (≈1000+ cfs), North Fork inflow alone won’t come close to matching outflow.
Add South Fork + locals and you still end up with net negative or, at best, barely neutral.
So in practical terms:
By July 1, I’d expect the North Fork to be down in the ~700–900 cfs band, and the reservoir to be past its seasonal peak and already starting to drop.
