Day 24 (2026-03-24) — 15th consecutive zero-precipitation day
Zero precipitation across the entire watershed for the 15th consecutive day. All 37 HUC12s recorded 0.0" in the 24-hour period. 7-day antecedent precipitation remains 0.0" everywhere (with a trivial 0.003" in the far eastern ungauged HUC12 110100050508).
No rainfall-driven responses. All gauges continue deep baseflow recession. End-of-day values compared to Day 23:
| Gauge | Day 23 EOD | Day 24 EOD | Change | Daily Rate |
|---|---|---|---|---|
| Boxley | 2.01 ft | 1.96 ft | -0.05 ft | -0.10%/hr |
| Ponca | 109 cfs | 104 cfs | -5 cfs | -0.19%/hr |
| Pruitt | 3.77 ft / 108 cfs | 3.69 ft / 92.2 cfs | -0.08 ft / -15.8 cfs | Height: -0.09%/hr |
| St. Joe | 3.79 ft / 275 cfs | 3.75 ft / 263 cfs | -0.04 ft / -12 cfs | -0.18%/hr (CFS) |
| Harriet | 3.85 ft / 320 cfs | 3.81 ft / 300 cfs | -0.04 ft / -20 cfs | -0.26%/hr (CFS) |
| Richland | 1.06 ft | 1.05 ft | -0.01 ft | Near floor |
| Bear Creek | 2.34 ft / 7.67 cfs | 2.32 ft / 6.6 cfs | -0.02 ft / -1.07 cfs | -0.58%/hr (CFS) |
Key observations:
Ponca: Dropped from 109→104 cfs. An interesting feature appeared mid-afternoon: discharge ticked up from 104→112 cfs between ~16:30-17:15 CST, then slowly fell back to 104 by 23:30. This is a ~8% bump with no precipitation anywhere in the watershed. Possible causes: (a) diurnal evapotranspiration cycle releasing stored water as temps cool, (b) rating curve noise at low flow, (c) minor karst spring pulse. Given no rain anywhere, this is noise/diurnal — not hydrologically significant.
Pruitt: CFS now regularly dropping below 100 — hitting 90.3 cfs at 17:30 CST. This is the first time Pruitt has been observed below the "Too Low" threshold (100 cfs) during the study. Height dropped to 3.68 ft minimum. The CFS scatter remains large: 90.3-108 cfs range (±9%) over the day while height varied only 3.68-3.77 ft (±1.2%). This confirms the low-stage CFS unreliability issue. The height-based recession is more informative: Pruitt is dropping ~0.04 ft/day from the ~3.77 ft midpoint yesterday to ~3.70 ft midpoint today.
Pruitt is now firmly in "Too Low" territory (<100 cfs) for significant portions of the day. Per local knowledge about channel scouring directing flow to river right, the actual flow may be somewhat higher than the gauge reads.
St. Joe: Continuing slow decline. Height midpoint ~3.75 ft, CFS midpoint ~263. Still above "Optimal" threshold (200 cfs) but declining. The height noise (±0.03 ft) is consistent with the gauge precision limits at these low levels.
Harriet: CFS declined from ~320→300, with the midpoint of height settling at ~3.81 ft. The height showed a clear step-down around 18:00 from 3.82→3.80 ft level, corresponding to CFS dropping from ~300→295 range.
Bear Creek: Now showing readings at 6.58 cfs (the lowest observed in the study). Height dropped to 2.32 ft. The CFS is clearly quantized — alternating between 7.67, 7.19, and 6.58 cfs, reflecting discrete rating curve steps at this tiny flow level. True baseflow is somewhere in the 6.5-7.2 cfs range. Specific discharge: ~0.028 cfs/km².
Richland Creek: Hovering at 1.04-1.05 ft with occasional excursions to 1.02-1.03. The late-evening readings (20:45-21:15) hit 1.02 ft — the lowest observed in the study — before rebounding to 1.04-1.05. This karst-influenced gauge continues to show ±0.02 ft variability even at baseflow.
None — no rain.
No event to track.
The extended dry recession continues to provide valuable baseflow characterization data. All gauges are still declining after 15 dry days.
Recession rate evolution (Days 22→23→24):
| Gauge | Day 22 Rate | Day 23 Rate | Day 24 Rate | Trend |
|---|---|---|---|---|
| Ponca | ~0.24%/hr | ~0.22%/hr | ~0.19%/hr | Decelerating — approaching floor |
| St. Joe | ~0.34%/hr | ~0.34%/hr | ~0.18%/hr | Decelerating noticeably |
| Harriet | ~0.33%/hr | ~0.33%/hr | ~0.26%/hr | Decelerating |
All three mainstem gauges with reliable CFS are now showing clear deceleration in recession rates, suggesting baseflow floors are being approached. Ponca is furthest along; St. Joe showed a notable drop from ~0.34→0.18%/hr.
Ponca afternoon bump: The 104→112→104 cfs cycle between 16:30-19:00 with zero precipitation is curious. It could represent a diurnal cycle (evapotranspiration shuts down in late afternoon, releasing a small pulse of stored groundwater), or simply rating curve noise. If this pattern repeats on subsequent dry days, it would suggest a real diurnal signal. Confidence in any explanation: Low.
Pruitt breaking below 100 cfs: This is a meaningful milestone. The gauge is now reading below the "Too Low" recreation threshold for significant parts of the day. Combined with the known river-right flow diversion issue, Pruitt-to-St. Joe paddling would be marginal at best in current conditions.
Bear Creek new study-low: At 6.58 cfs / 2.32 ft, Bear Creek continues setting new lows. The previous "floor" estimate of 7.0-7.7 cfs was clearly too high.