Day 29 (2026-03-29) — Continued Drought Recession
Zero precipitation across the entire watershed. All 37 HUC12s recorded 0.0" for the 24-hour period. This is the second consecutive dry day and the 21st day without significant precipitation (since Event 3 ended ~March 12, with only the trace 0.1-0.4" on March 27 breaking the streak). The 7-day antecedent precipitation remains unchanged from Day 28 at 0.10-0.40" (reflecting only the March 27 trace amounts).
All gauges continued declining to new study-period lows. No significant rises detected at any gauge.
End-of-day values and study-low status:
| Gauge | Day 28 EOD | Day 29 EOD | Change | New Study Low? |
|---|---|---|---|---|
| Boxley | 1.84 ft | 1.82 ft | -0.02 ft | Yes |
| Ponca | 89.2 cfs | 87.8 cfs | -1.4 cfs (-1.6%) | Yes |
| Pruitt | 3.55 ft / 62.6 cfs | 3.52 ft / 58.1 cfs | -0.03 ft / -4.5 cfs (-7.2%) | Yes (height); CFS hit 50.9 intraday |
| St. Joe | 3.56 ft / 207 cfs | 3.52 ft / 195 cfs | -0.04 ft / -12 cfs (-5.8%) | Yes — approaching Low-but-Floatable threshold (200 cfs) |
| Harriet | 3.64 ft / 219 cfs | 3.62 ft / 210 cfs | -0.02 ft / -9 cfs (-4.1%) | Yes |
| Richland | 0.94 ft | 0.92 ft | -0.02 ft | Yes |
| Bear Creek | 2.29 ft / 5.0 cfs | 2.28 ft / 4.6 cfs | -0.01 ft / -0.4 cfs | Yes |
Notable observations:
St. Joe is crossing the Low-but-Floatable/Optimal boundary. CFS readings dipped to 187 cfs at 19:00 CST (below the 200 cfs Optimal threshold). The day's average was ~198 cfs, straddling the threshold. St. Joe has effectively transitioned from Optimal to Low-but-Floatable as of today.
Pruitt CFS anomaly continues worsening. Ponca reads 87.8 cfs while Pruitt reads 58.1 cfs — a 34% decrease across a gaining reach. This is physically impossible and further confirms the Pruitt low-flow gauge measurement issue documented in local knowledge. The Pruitt height data (3.52 ft) is more reliable. The Pruitt CFS intraday low of 50.9 cfs at 17:45 CST represents the study's lowest recorded value there, and the height-CFS scatter has widened considerably (3.47-3.57 ft height range corresponding to 50.9-65.8 cfs range — a ±13% variation at the same approximate height).
Pruitt height variability increased. The 0.10 ft range today (3.47-3.57) is wider than the 0.09 ft range yesterday, despite no precipitation. This likely reflects increasing turbulence in the stage-discharge relationship at very low flows, possibly related to the river-right channel shift noted in local knowledge.
None — no precipitation.
No propagation events to track.
None active.
Recession rate update (Day 29, now 18+ days post-Event 3):
| Gauge | Day 28→29 Decline Rate | Previous Estimated Rate | Trend |
|---|---|---|---|
| Ponca | ~1.6%/day | ~4-5%/day | Decelerating — approaching asymptotic baseflow |
| St. Joe | ~5.8%/day | ~5%/day | Stable |
| Harriet | ~4.1%/day | ~7-8%/day | Decelerating |
Ponca's recession has slowed dramatically from the ~4-5%/day rate observed in mid-March to ~1.6%/day, suggesting it is approaching a spring-fed baseflow floor. At this rate, Ponca would reach ~85 cfs within 2-3 days before likely stabilizing. This is consistent with karst-influenced baseflow behavior — rapid initial drainage of epikarst storage followed by asymptotic approach to a perennial spring-fed minimum.
Recreational status: St. Joe has crossed below the Optimal threshold (200 cfs) for part of the day, entering Low-but-Floatable range (40-200 cfs). All upstream gauges (Boxley, Ponca, Pruitt) are deep into Too Low territory. Harriet remains in Optimal (210 cfs, threshold 200 cfs) but is declining ~4%/day and will cross into Low-but-Floatable within 1-2 days without rain. The watershed urgently needs precipitation to sustain any recreational flows.