Daily Analysis

Day 23 (2026-03-23) — Continued Extended Dry Period

1. PRECIPITATION SUMMARY

Zero precipitation across the entire watershed for the 13th consecutive day. All 37 HUC12s recorded 0.0" QPE. The 7-day antecedent precipitation has now dropped to 0.0" across all HUC12s (with one trivial exception: HUC12 0508 at 0.003"). This is the first day of the study with a truly watershed-wide zero 7-day antecedent — a clean slate for the next rainfall event.

2. GAUGE RESPONSES

All gauges continued their slow baseflow recession. No significant rises at any gauge.

End-of-day values and changes from Day 22:

Gauge Day 22 EOD Day 23 EOD Change Status
Boxley 2.07 ft 2.01 ft -0.06 ft Still declining — new study low
Ponca 115 cfs 109 cfs -6 cfs (-5.2%) Below previous estimate of floor (~110-115)
Pruitt 3.84 ft / 124 cfs 3.77 ft / 108 cfs -0.07 ft / -16 cfs Height: new study low; CFS increasingly noisy
St. Joe 3.86 ft / 298 cfs 3.79 ft / 275 cfs -0.07 ft / -23 cfs Continuing decline
Harriet 3.90 ft / 347 cfs 3.85 ft / 320 cfs -0.05 ft / -27 cfs Continuing decline
Richland 1.13 ft 1.06 ft -0.07 ft Significant drop — new study low
Bear Creek 2.37 ft / 9.3 cfs 2.34 ft / 7.7 cfs -0.03 ft / -1.6 cfs Below previous baseflow floor

3. RAINFALL-RESPONSE PAIRS

None — no rainfall.

4. DOWNSTREAM PROPAGATION

No events to track.

5. MULTI-DAY EVENTS

None.

6. ANOMALIES OR SURPRISES

Several significant findings from extended drought:

A. Bear Creek has dropped below its previously established baseflow floor. On Day 22, I declared Bear Creek had reached a floor at ~8.7-9.3 cfs / 2.36-2.37 ft. Today it dropped to 2.34 ft / 7.67 cfs. The CFS has stepped down to a new quantization level (7.67 cfs). This means the floor was NOT actually reached on Day 20 — it was still slowly declining. The previous "floor" assessment was premature. Bear Creek's true baseflow floor is lower than estimated, and may still be declining. Specific discharge now: ~0.032 cfs/km² (down from ~0.037).

B. Ponca has broken below the estimated ~110-115 cfs floor. Now reading 107-109 cfs at end of day. The recession rate at Ponca on Day 23: from 115→109 cfs over ~24 hrs = ~0.22%/hr, which is similar to Day 22's rate. Ponca is not yet at its true baseflow floor.

C. Richland Creek showed a notable drop. From ~1.13-1.15 ft range on Day 22 to 1.06-1.09 ft on Day 23. The early portion of Day 23 shows a rapid step-down from 1.14→1.09 ft around 01:45 CST (~0.05 ft in 30 min). This is not a smooth recession — it's a discrete drop, possibly related to karst spring behavior in the Richland sub-basin. As a spring-fed karst system, Richland Creek may exhibit step-function declines as specific conduit flow paths dewater. This is noteworthy for understanding the karst hydrology signal in this gauge.

D. Pruitt CFS reliability continues to deteriorate. Today's Pruitt CFS readings range from 104-126 cfs with substantial scatter (±10% at any given time), while the height shows a smoother trend from 3.84→3.77 ft. The CFS minimum of 104 represents the lowest Pruitt reading in the study. Per local knowledge about channel scouring directing flow to river right, the true discharge may be higher than what the gauge reads. The height record remains the more reliable metric.

E. Recession rate tracking (Day 23):

Gauge Day 22 Rate (%/hr) Day 23 Rate (%/hr) Trend
Ponca ~0.24 ~0.22 Slowly decelerating
St. Joe ~0.34 ~0.34 Steady
Harriet ~0.44 ~0.33 Decelerating notably

Harriet's recession rate dropped from ~0.44%/hr to ~0.33%/hr — the first clear sign of deceleration at this gauge. This suggests Harriet may be approaching its baseflow regime. St. Joe remains steady at ~0.34%/hr with no sign yet of leveling off.

F. Recreational status: All mainstem gauges are now firmly in "Too Low" territory. Ponca at 109 cfs is well below 150 cfs threshold. Pruitt at ~108 cfs is barely above 100 cfs "Too Low" threshold. St. Joe at 275 cfs and Harriet at 320 cfs remain in "Optimal" range but are approaching the lower end. At current recession rates, St. Joe could drop below 200 cfs (Low-but-Floatable threshold) in approximately 4-5 more dry days.