Daily Analysis

Day 30 of 90 — 2026-03-30

1. PRECIPITATION SUMMARY

Zero precipitation across the entire watershed. All 37 HUC12s show 0.0" for the 24-hour period. This is the 3rd consecutive day with zero precipitation (Days 28-30), extending the dry spell to 22 days since the last meaningful rain (March 8 Event 2 aftermath), with only the trace event on Day 27 (March 27, 0.1-0.4") breaking what is otherwise a continuous drought.

The 7-day antecedent precipitation remains unchanged from Days 28-29 (range 0.098-0.402" across HUC12s), reflecting only the Day 27 trace rain. The Day 27 rain will roll out of the 7-day window tomorrow (Day 31), at which point 7-day precip will drop to 0.0" across the entire watershed.

2. GAUGE RESPONSES

All gauges continued declining. No significant rises detected at any gauge. Summary of current conditions vs. Day 29:

Gauge Day 29 End Day 30 End Change Recreational Status
Boxley 1.82 ft 1.80 ft -0.02 ft New study low — Too Low
Ponca 87.8 cfs 85.1 cfs -2.7 cfs New study low — Too Low (<150)
Pruitt 3.52 ft / 58.1 cfs 3.50 ft / 55.1 cfs -0.02 ft Too Low (CFS unreliable)
St. Joe 3.52 ft / 195 cfs 3.46 ft / 179 cfs -0.06 ft / -16 cfs Dropped below Low-but-Floatable (<200) → Too Low
Harriet 3.62 ft / 210 cfs 3.59 ft / 197 cfs -0.03 ft / -13 cfs Dropped below Optimal (200) → Low-but-Floatable
Richland 0.92 ft 0.90 ft -0.02 ft New study low
Bear Creek 2.28 ft / 4.6 cfs 2.28 ft / 4.6 cfs ~0 At/near study low (height touched 2.27 ft)

Key threshold crossing: St. Joe has now dropped below the "Low but Floatable" threshold of 200 cfs, reading 175-179 cfs by end of day. This is the first time in the study that St. Joe has been in "Too Low" classification. Harriet has dropped from Optimal into Low-but-Floatable territory (197 cfs, just below the 200 cfs threshold).

Ponca baseflow floor update: Ponca dropped from 87.8 to 85.1 cfs today — a decline of 2.7 cfs (3.1%). My Day 29 estimate of a floor at ~85-87 cfs appears to be very close. The rate of decline has slowed further: - Day 28→29: 89.2 → 87.8 = -1.4 cfs/day (~1.6%/day) - Day 29→30: 87.8 → 85.1 = -2.7 cfs/day (~3.1%/day)

The apparent acceleration is misleading — Ponca held at 87.8 for most of Day 29 and then the reading resolution stepped down to 85.1 late on Day 30. This is likely a rating curve discretization artifact at very low flows. The true floor may be at or very near 85 cfs. I'll watch for further decline tomorrow.

St. Joe recession rate: From Day 29 average (~195 cfs) to Day 30 average (~185 cfs), the decline is approximately 5.1%/day, consistent with the ~5.8%/day rate estimated previously.

Harriet recession rate: From Day 29 (~210 cfs) to Day 30 (~201 cfs average), decline is approximately 4.3%/day, consistent with the ~4.1%/day rate.

3. RAINFALL-RESPONSE PAIRS

None — no precipitation.

4. DOWNSTREAM PROPAGATION

No propagation events to track.

5. MULTI-DAY EVENTS

Extended drought continues. Now 22 days since last significant precipitation. The entire watershed is in deep baseflow recession.

6. ANOMALIES OR SURPRISES

Richland Creek karst noise: Richland showed an unusual spike pattern today — from a declining trend around 0.90-0.91 ft, it spiked briefly to 0.93-0.94 ft at 15:00-15:15 and again at 19:15 (0.94 ft). These ±0.03 ft spikes with zero precipitation reinforce the previously documented karst noise floor at this gauge. The 0.03 ft/hr "rise" flagged at 15:15 is entirely within the karst noise envelope and should not be interpreted as a hydrological response.

Pruitt CFS scatter worsening: Pruitt CFS ranged from 49.5-59.6 today at heights of 3.46-3.53 ft. The Ponca-to-Pruitt discrepancy is now extreme: Ponca at 85.1 cfs while Pruitt reads 49.5-55.1 cfs. This confirms local knowledge about channel scouring shifting flow away from the gauge. Pruitt CFS values below ~80 cfs are essentially non-informational for absolute discharge.

Bear Creek approaching new low: Bear Creek CFS dropped to 4.19 cfs (from 4.59) in the late afternoon/evening, a new study low. Height touched 2.27 ft, also a new low. This gauge is approaching its spring-fed baseflow floor.