Four days after the valves started alternating in the metro area, the daily monitoring charts that the Autoridad de Acueductos y Alcantarillados publishes every morning at 5:00 tell a plain story: the water is still going down. This is the follow-up to our explainer on the rationing plan, built the same way — from AAA’s own numbers, which we read off its charts daily for our reservoir board.
Carraízo: still falling, 43 centimeters of runway
Carraízo — the reservoir behind the rationing — stood at 37.64 meters the morning the rotation began. This morning it reads 37.43: a drop of 21 centimeters in four days, about 5 centimeters a day. The level sits in AAA’s ajustes (operational adjustments) band, 43 centimeters above the line at 37.00 where the control band begins — the band AAA’s own alert ladder describes as drought controls, rationing-level measures.
One honest caveat: we can’t say whether rationing has slowed the decline, because there is no comparable daily series from before August 7 to measure against — AAA’s charts rotate daily and we began archiving them the day the plan started. What the chart does say is that at the current pace, Carraízo touches the control line around August 19–20. That is the territory where the plan’s published Phase 2 — one day with water, three without — stops being hypothetical.
The La Plata contrast
The sharper story may be the reservoir that isn’t rationed. La Plata — 130,828 customers across Bayamón, Dorado, Guaynabo, Naranjito, Toa Alta, Toa Baja, Vega Alta, Cataño and Corozal — has fallen from 46.55 to 46.20 meters over the same four days: nearly 9 centimeters a day, close to double Carraízo’s pace, and consistent with the 60-centimeter weekly drop reported Sunday.
AAA executive director Luis González Delgado ruled out immediate rationing at La Plata on Monday, saying pressure adjustments are holding the daily drop below 10 centimeters and that decisions depend on the weather in the coming weeks. La Plata sits in the observación band, 1.30 meters above its ajustes line — months of runway at the current pace, but Toa Alta’s mayor is already calling for a preventive plan, and the Secretary of State has conceded the mayors and the utility aren’t communicating well. Meanwhile the mitigation that might actually add capacity at Carraízo — dry dredging of exposed shoreline — was still being assessed as of Friday, with the DRNA saying no permits should be needed.
The rain, which is the whole ballgame
Every number above changes if it rains over the right mountains. Here is the honest outlook, from the National Weather Service in San Juan this morning:
A tropical wave is crossing the region today into early Wednesday, and the NWS forecast discussion calls it the week’s main event: tropical moisture riding ahead of the wave, the best rain and thunderstorm potential falling on eastern Puerto Rico — the right side of the island for Carraízo — with localized flooding possible where storms train. Behind it, the pattern flips the wrong way: drier Saharan air spreads in Wednesday night, strengthening trade winds arrive Thursday, and by Friday the forecast is essentially dry. Another wave approaches late Thursday but is expected to stay east of the island.
Further out, the National Hurricane Center is monitoring multiple Atlantic disturbances — the forecasters’ own words are that it is too early to determine any potential impacts to Puerto Rico. In a drought summer, that sentence cuts both ways.
What to watch this week
Thursday’s Drought Monitor. The U.S. Drought Monitor’s next weekly map lands Thursday, the first to reflect this week’s wave — our town-by-town map updates with it. The control line. Carraízo at 37.00 is the number that turns Phase 2 from a document into a schedule; the reservoir board tracks the gap daily. The rotation itself — Zone 1’s water came back this morning at 6:00; the switch calendar and sector lists are on the water page, and the running story is on the water crisis timeline.