Day 44 (April 13, 2026) — Dry day, continued recession from Event 4
Zero precipitation across the entire watershed. All 37 HUC12s recorded 0.00" for the 24-hour period. This is the second consecutive day of essentially zero rainfall (Apr 12 had only trace amounts totaling <0.05" watershed-wide). The 7-day antecedent precipitation is now dropping significantly — most HUC12s are below 0.3", with only the Harriet direct sub-watersheds retaining higher values from Event 5 (Water Creek still at 1.10", Tomahawk Creek 0.78").
All gauges continue declining. No significant rises at any gauge. This is a clean recession day — ideal for extending the Event 4 recession analysis.
End-of-day values and daily changes:
| Gauge | EOD Apr 12 | EOD Apr 13 | Change | Daily % Decline |
|---|---|---|---|---|
| Boxley | 2.34 ft | 2.26 ft | -0.08 ft | ~3.4% (height) |
| Ponca | 136 cfs | 127 cfs | -9 cfs | ~6.6% |
| Pruitt | 174 cfs / 3.99 ft | 158 cfs / 3.93 ft | -16 cfs / -0.06 ft | ~9.2% |
| St. Joe | 409 cfs / 4.17 ft | 360 cfs / 4.04 ft | -49 cfs / -0.13 ft | ~12.0% |
| Harriet | 529 cfs / 4.21 ft | 485 cfs / 4.14 ft | -44 cfs / -0.07 ft | ~8.3% |
| Richland | 1.42 ft | 1.35 ft | -0.07 ft | ~4.9% (height) |
| Bear Creek | 3.83 cfs / 2.26 ft | 3.2 cfs / 2.24 ft | -0.63 cfs / -0.02 ft | ~16.4% |
Recreational status: - Ponca: 127 cfs — firmly in "Too Low" (<150 cfs). Has now been below 150 since late Apr 12. Ponca total floatable duration (>150 cfs) from Event 4: ~8.5 days (Apr 4 ~11:00 to Apr 12 ~17:00). - Pruitt: 158 cfs — in "Low but Floatable" (100-200 cfs). Crossed below 200 cfs on Apr 12; Event 5 briefly re-entered Optimal on Apr 11. Now solidly declining within Low-but-Floatable range. - St. Joe: 360 cfs — still in Optimal (>200 cfs). Declining ~12%/day. - Harriet: 485 cfs — still in Optimal (>200 cfs). Declining ~8.3%/day.
No new pairs to report — zero precipitation today.
No new propagation signals. The entire mainstem chain is in pure recession.
Event 4 recession — Day 11 (9 days post-peak at St. Joe; 8 days post-peak at Harriet):
This extends our cleanest recession dataset. Key observations:
St. Joe recession rate comparison: - Day 10 (Apr 12): ~5.5%/day (409 cfs) - Day 11 (Apr 13): ~12.0%/day (360 cfs)
This is a significant acceleration from yesterday's dramatically slow 5.5%/day. The Day 10 value now appears to have been anomalously low — possibly reflecting a brief bump from Event 5 propagation reaching St. Joe, which temporarily slowed the apparent recession. Today's 12% rate is more consistent with the Day 7-9 trend (~14-15%/day) but showing continued deceleration from those values.
Revised St. Joe projections: At 360 cfs declining ~10-12%/day (and continuing to decelerate), St. Joe should drop below 200 cfs (end of Optimal) around Apr 18-21. This narrows the previous projection range of Apr 24-28, which was based on the anomalously slow Day 10 rate. Total Event 4 Optimal duration at St. Joe: projected ~330-400 hours (14-17 days).
Harriet recession: - Day 10 (Apr 12): ~10.9%/day - Day 11 (Apr 13): ~8.3%/day
Harriet's rate has decelerated to 8.3%, the slowest yet observed. At 485 cfs declining 7-9%/day, Harriet should drop below 200 cfs around Apr 20-24. Total Event 4 Optimal duration at Harriet: projected ~370-470 hours (15-20 days).
Upper gauge baseflow levels: - Boxley at 2.26 ft — approaching what may be a seasonal baseflow floor. Pre-Event 4 was 1.84 ft (very dry after 19-day drought). Current level suggests some sustained groundwater/spring contribution from the moderately wet spring season. - Ponca at 127 cfs — below its pre-Event 4 level (87.8 cfs was the extreme dry value; 145 cfs was the pre-Event 5 level). The Event 4 pulse has fully passed through the upper watershed.
St. Joe Day 10 recession rate revised: The 5.5%/day rate observed on Day 10 (Apr 12) now appears to have been artificially depressed, likely by the arrival of the Event 5 propagation bump. Today's 12% rate, when viewed alongside the full recession curve, suggests the true underlying recession rate at St. Joe is still decelerating but along a more gradual trajectory (from ~40%/day → ~15%/day → ~12%/day) rather than the dramatic step-change to 5.5% that appeared yesterday. This is an important lesson: Event 5 propagation, even though it produced only ~4 cfs rise at St. Joe, appears to have masked the true recession rate for 1-2 days. Small perturbations can contaminate recession analysis at large-basin gauges where daily declines are themselves small in absolute terms.
Comparison with local knowledge: The Ponca gauge crossing below 150 cfs (Too Low threshold) on Day 8-9 post-Event 4 peak is consistent with the general pattern that upper mainstem gauges return to low-flow conditions within about a week of moderate events. The sustained Optimal flows at St. Joe and Harriet — projected 14-20 days total — reinforce the watershed-scale storage hypothesis: the 1,342 km² contributing to St. Joe and 2,775 km² to Harriet provide substantially more baseflow persistence than the 298 km² above Ponca.