Another light rainfall day, though with a notable spatial gradient. Precipitation was concentrated in the eastern/downstream portions of the watershed (ungauged zones) with very little reaching the western headwaters.
Spatial pattern (west to east gradient): - Boxley zone: 0.027" — trace - Ponca zone: 0.071" — trace - Richland zone: 0.026" — trace - Bear Creek zone: 0.044" — trace - St. Joe zone: 0.094" avg, but highly variable — Cane Branch (0309) got 0.199", Flatrock (0206) got 0.282", Rocky Hollow (0402) got 0.123" - Pruitt zone: 0.261" — Cove Creek (0204) received 0.305", Hoskin Creek (0207) got 0.217" - Harriet zone: 0.211" — Water Creek (0408) got 0.276", Tomahawk (0407) got 0.242", Dry Creek (0406) got 0.200" - Ungauged (below Harriet): 0.303" avg — Leatherwood (0508) got 0.451" (highest in watershed), Clabber (0503) got 0.428", Boat Creek (0504) got 0.402"
Peak intensities remained low: max 0.109"/hr at Leatherwood Creek (ungauged). Most gauged zones peaked at 0.02–0.09"/hr.
Timing: Most rainfall arrived in a single pulse between 01:00–04:00 UTC (7 PM–10 PM CST on 3/1, rolling into early 3/2), with some HUC12s showing a secondary pulse around 08:00–10:00 UTC (2–4 AM CST).
7-day antecedent precipitation is now building slightly — eastern HUC12s showing 0.2–0.4" cumulative from the past week's light events. Western headwaters remain at 0.1–0.2". Still very dry by any standard.
No significant rises detected at any gauge. All gauges continue baseflow recession.
Updated baseflow values (2026-03-02 EOD):
| Gauge | EOD Value | Change from 3/01 EOD | Daily Recession |
|---|---|---|---|
| Boxley | 1.92 ft | -0.03 ft | -0.015 ft/day (consistent) |
| Ponca | 85.1 cfs | -2.7 cfs | ~3.1% (stepped down to new quantization level) |
| Pruitt | 69.4 cfs / 3.48 ft | -2.9 cfs / -0.02 ft | ~4.0% |
| St. Joe | 171 cfs / 3.45 ft | -6 cfs / -0.02 ft | ~3.4% |
| Harriet | 189 cfs / 3.57 ft | -12 cfs / -0.03 ft | ~6.0% |
| Richland | 0.93 ft | -0.02 ft | -0.02 ft/day (accelerating) |
| Bear Creek | 7.2 cfs / 2.33 ft | 0 cfs / 0 ft | Stepped down to 7.19 dominant |
Key observations:
Ponca stepped down to the 85.1 cfs quantization level around 18:00. It held at 86.4 for most of the day after dropping from the 87.8 level. Recession is accelerating slightly (was ~1.4%/day, now ~3.1%).
Pruitt diurnal cycling continues. Nighttime highs ~3.50-3.51 ft (72-74 cfs), afternoon lows now reaching 3.44 ft (63.7 cfs). The amplitude is widening slightly: today's range was 0.07 ft / 10 cfs vs yesterday's 0.06 ft / 9 cfs. The minimum value of 63.7 cfs is a new study low. Overall baseflow is declining faster now (~4%/day vs ~3%/day previously).
Harriet broke below 200 cfs definitively. It had been hovering at the 200-201 boundary for ~2 days but today showed a clear step down through the day: 210→206→201→197→193→189 cfs. The earlier "stabilization" hypothesis is now contradicted — Harriet is resuming recession and appears to be accelerating (6%/day vs prior 1.7%/day). This is the most significant observation today.
St. Joe noise band has narrowed somewhat (0.05 ft range today vs 0.10 ft on 3/01). Mean level continues declining slowly. Now clearly in "Low but Floatable" territory at ~171 cfs.
Bear Creek has fully transitioned to the 7.19 cfs quantization level by late afternoon. The 7.67 level was still dominant through mid-morning but 7.19 took over by ~17:00. Height now firmly at 2.33 ft.
Richland Creek continues declining to new study lows — now reaching 0.93 ft regularly. The brief early-morning blip to 0.98 ft at 01:00 CST appears to be noise/measurement artifact (single reading, immediate return).
None. Despite cumulative 2-day totals approaching meaningful levels in some zones (Pruitt zone: 0.246 + 0.261 = 0.507" over 2 days; Harriet zone: 0.262 + 0.211 = 0.473"), no gauge response was detected. This is another important non-detection:
| Zone | 2-Day Total | Peak 1hr (today) | 7-Day Antecedent | Response |
|---|---|---|---|---|
| Pruitt (Cove Creek) | 0.599" | 0.086"/hr | 0.305" | None |
| Harriet (Water Creek) | 0.600" | 0.067"/hr | 0.332" | None |
| Harriet (Tomahawk) | 0.509" | 0.068"/hr | 0.273" | None |
| St. Joe (Cane Branch) | 0.422" | 0.079"/hr | 0.225" | None |
This significantly raises the detection threshold estimate. Under dry antecedent conditions, even 0.5-0.6" spread over 2 days at intensities ≤0.09"/hr produces no detectable response. The true detection threshold under these conditions is likely >0.6" per event (or requires higher intensity, >0.1"/hr sustained).
No rises to track. Continued recession at all gauges.
The light rainfall from yesterday (3/01) and today (3/02) represents a multi-day light precipitation pattern. Despite cumulative totals reaching 0.5-0.6" in some individual HUC12s, the low intensity (never exceeding 0.11"/hr peak) means virtually all precipitation is being absorbed by the extremely dry soil column. This is consistent with initial infiltration capacity exceeding rainfall intensity by a wide margin.
1. Harriet baseflow stabilization hypothesis is CONTRADICTED. Yesterday's hypothesis that Harriet was approaching a baseflow floor near 200 cfs appears wrong. Today Harriet dropped from ~201 to 189 cfs — a 6% decline in one day, the fastest rate observed yet. The previous "stabilization" was likely either (a) a brief pause in an ongoing recession, or (b) the very light rain from 3/01 (0.26" in Harriet zone) providing just enough interflow to temporarily offset recession without producing a detectable rise. Now that a full day has passed since that light rain, the recession has resumed with apparent acceleration. Confidence in the stabilization hypothesis drops to Very Low / Contradicted.
2. Ponca-Pruitt discharge inversion continues widening: - Today: Ponca 85.1 cfs, Pruitt 69.4 cfs → deficit ~15.7 cfs (afternoon values where Pruitt is at its diurnal low make this comparison tricky; using late-night values: Ponca 87.8, Pruitt ~72.3 → deficit ~15.5 cfs) - The deficit remains in the 15-16 cfs range, consistent with prior days. The karst losing reach hypothesis remains well-supported.
3. Ponca recession accelerating. Ponca was declining at ~1.4%/day over the first 4 days but dropped ~3% today (87.8→85.1). This could represent a step-change as it drops to a new quantization level, or genuine acceleration as the primary quantization level shifts.
4. Local knowledge comparison: The local knowledge entry about CFS rating curve reliability is relevant here — both Ponca and Pruitt were calibrated on Feb 17, 2026, only ~2 weeks before the study began. Given that we're still in a dry spell with no significant flow events since then, both rating curves should still be reasonably accurate for this flow range. The persistent Ponca > Pruitt CFS pattern across 5 days is more likely real than a rating curve artifact, consistent with the local knowledge noting both gauges were recently calibrated.