Skip to content

Reservoirs

Levels for the 19 reservoirs on AAA's daily bulletin

Today's bulletin

14 of 19 reservoirs fell in 24 hours

4 rose and one held level.

We read the USGS gauges that underpin AAA's daily bulletin and publish the 5:00 AM reading for each of the 19 reservoirs, every day.

See the 19 reservoirsDetailed view

19

Reporting

of 19

14

Fell

of 19

4

Rose

of 19

What moved most

Yesterday's movement, reservoir by reservoir.

The largest falls

3 of 14

  1. Dos BocasSafety-0.11m88.43 m
  2. LucchettiSafety-0.08m171.54 m
  3. La PlataObservation-0.07m45.34 m

Selected by: the 24-hour change, most negative first, among reservoirs that reported

The largest rises

3 of 4

  1. GuayoSafety+0.07m442.23 m
  2. GarzasSafety+0.03m735.98 m
  3. GuayabalObservation+0.02m102.52 m

Selected by: the 24-hour change, most positive first, among reservoirs that reported

The 19, at a glance

Every reservoir, drawn.

See all 19

The phase lines sit at the same height on every card, so what moves is the water.

  1. Río Blanco

  2. Toa Vaca

  3. Cidra

  4. Matrullas

  5. Fajardo

  6. Guayo

  7. Carraízo

  8. La Plata

8 of 19 · Selected by: percent of each reservoir's own range, lowest first

Against its own normal

Lowest against normal

Patillas

3.85 m below normal for this date

A ±7-day window around August 23, 2026, this reservoir's own most recent reading. · 63.46 m

Selected by: the lowest percentile against normal, among reservoirs with 15 or more years of record

The latest report

Where these figures come from.

Bulletin
August 23, 2026
Reading time
5:00 AM (AST)
Coverage
19 of 19 reservoirs reporting
Last run
Aug 23, 2026, 1:17 PM

How we read the data

Every figure on this portal is the 5:00 AM AST reading from the USGS gauge, every day, at every reservoir. AAA's daily bulletin is drawn at 4:55 AM and carries the freshest reading that had arrived by press time; the gauges transmit once an hour, and the 5:00 AM reading is published around 5:57 AM. On days when levels move quickly the two figures can therefore differ by about a centimetre. Each is correct for its own cut-off. Ours holds the same 24-hour interval every day, which is what makes our day-over-day changes directly comparable to one another.

We read the same USGS gauges that underpin the bulletin. The alert phases (Overflow, Safety, Observation, Operational adjustments, Control) are the thresholds AAA publishes for each reservoir; AAA prints them in Spanish, as Desborde, Seguridad, Observación, Ajustes and Control.

Source

Data: U.S. Geological Survey (USGS)

Provisional data

Provisional data: values are preliminary, have not been reviewed or approved by the U.S. Geological Survey, and are subject to revision or removal as the record is finalized. Do not use them for decisions involving personal or public safety, or property.

Daily reservoir level bulletin: Autoridad de Acueductos y Alcantarillados de Puerto Rico.

This portal is not an official channel of the Autoridad de Acueductos y Alcantarillados. For service notices, consult AAA.