Day 42 of the metro rotation plan — interruptions paused since September 2, AAA has not cancelled the plan. This morning’s 5:00 chart from the Autoridad de Acueductos y Alcantarillados shows Carraízo at 40.64 meters — up 58 centimeters from yesterday, and La Plata at 44.40 meters — up 4 centimeters from yesterday.
This is the 38th entry in our daily chart check (yesterday’s is here), built the same way every morning — from AAA’s own numbers, read off its charts for our reservoir board.
Carraízo: a rise
Carraízo gained ground overnight. This morning’s chart puts it at 40.64 meters — up 58 centimeters from yesterday, in the seguridad band. The next line on the chart — into the observación band — sits at 39.70 meters, 0.94 meters below this morning’s reading.
Carraízo · September 18
- Level today
- 40.64 mband: seguridad
- Change since yesterday
- +58 cm
- To the observación line
- 0.94 mline at 39.70 m
- At the current pace
- rising
La Plata: a rise
La Plata gained ground overnight. This morning’s chart puts it at 44.40 meters — up 4 centimeters from yesterday, in the ajustes band. The next line on the chart — into the control band — sits at 40.50 meters, 3.90 meters below this morning’s reading.
If your water comes from La Plata — Dorado, Guaynabo, Naranjito, Toa Alta, Toa Baja, Vega Alta, Bayamón, Cataño, Corozal — this is the reservoir to watch; AAA lists 130,828 client accounts on it.
La Plata · September 18
- Level today
- 44.40 mband: ajustes
- Change since yesterday
- +4 cm
- To the control line
- 3.90 mline at 40.50 m
- At the current pace
- rising
What the numbers say
Over the past week Carraízo has been rising an average of 24.2 cm a day. Since the rotation began 40 days ago it has gained 311 cm, from 37.53 m. It sits 0.94 m above the observación line (the next band down), at 40.64 m in the seguridad band. If this week’s rise held, the level would climb into the desborde band above (line at 40.95 m) in about 1 days, around September 20. Nearby USGS gauges recorded 5.76 in of rain this week, most of it September 16 (2.21 in). After the 0.6 in on September 13, the next morning’s reading was +2 cm. After the 1.6 in on September 14, the next morning’s reading was +9 cm.
Over the past week La Plata has been rising an average of 2.5 cm a day, a reversal from a 6.7 cm-a-day decline the week before. Since August 9 it has lost 198 cm, from 46.38 m. It sits 3.90 m above the control line (the next band down), at 44.40 m in the ajustes band. If this week’s rise held, the level would climb into the observacion band above (line at 44.90 m) in about 20 days, around October 8. Nearby USGS gauges recorded 2.69 in of rain this week, most of it September 14 (1.09 in). After the 1.09 in on September 14, the next morning’s reading was +6 cm. After the 0.6 in on September 16, the next morning’s reading was -4 cm.
Over the past week Cidra has been rising an average of 4.3 cm a day. That is 4 straight mornings higher, +27 cm in all. Since August 9 it has gained 40 cm, from 400.13 m. It sits 0.30 m above the ajustes line (the next band down), at 400.53 m in the observación band. If this week’s rise held, the level would climb into the seguridad band above (line at 401.71 m) in about 27 days, around October 16. Nearby USGS gauges recorded 6.26 in of rain this week, most of it September 16 (2.19 in). After the 1.6 in on September 14, the next morning’s reading was +1 cm. After the 2.19 in on September 16, the next morning’s reading was +17 cm.
What to watch
- Carraízo: whether the rise survives a dry week — this week’s gain came with 5.76 in of rain nearby.
- La Plata: whether the rise survives a dry week — this week’s gain came with 2.69 in of rain nearby.
- Cidra: whether the rise survives a dry week — this week’s gain came with 6.26 in of rain nearby.
The other rationing reservoir
Cidra · September 18
- Level today
- 400.53 mband: observación
- Change since yesterday
- +8 cm
- To the ajustes line
- 0.30 mline at 400.23 m
- At the current pace
- rising
Numbers from AAA’s Monitoreo Diario chart of 2026-09-18, read each morning for our reservoir board — where the levels, the bands, and the live rain gauges update daily. Rain figures are USGS gauges within 12 km of each reservoir (a proximity proxy, not a basin measurement). Day counts start 2026-08-08, when the metro rotation took effect. Straight-line dates are arithmetic, not forecasts.