# Río Inabón

Río Inabón is one of the 14 rivers in the municipality of Ponce, Puerto Rico. With a length of some 32.01 kilometers (19.89 mi), it is Ponce's second longest river after Río Jacaguas. It is fed by the Río Anón, Río Guayo (which itself is fed by the Chiquita Brook and the Indalecia Brook) and the Emajagua Brook. It is also fed by Río Bacas and Río de las Raices. Originating at an altitude of approximately 4,100 feet (1,200 m), it forms at a higher altitude than any of the other 13 rivers in the municipality, and at one of the highest points of any river in Puerto Rico. With a watershed area covering 38.18 square miles, Río Inabón also has the second largest basin area of any of the municipality's 14 rivers after Río Jacaguas.

## Origin and course

Río Inabón has its origin at 4,100 feet (1,200 m) above sea level in Cerro Camacho, in barrio Anón, near Anón's boundary with the municipality of Jayuya. The river runs mostly parallel to PR-511.

## Uses

"A provision in The Treaty of Paris of 1898 grants the Serrallés family exclusive rights to the Río Inabón. This river winds through Puerto Rico’s volcanic mountains, and is the exclusive water source for DonQ Rum". Today Río Inabón is one of the most popular rivers for swimming in southern Puerto Rico. Some 10 private reservoirs in the Ponce area are fed by the waters of Río Inabón.

## Environmental contamination

In January 2011, Puerto Rico Representative Víctor Vassallo Anadón presented a bill into the Puerto Rico House of Representatives that would improve the sewer system of residents near the river to avoid contaminating it with sewer waters.

## Endangered species

The fern Thelypteris inabonensis found at the headwaters of Río Inabón and at the Toro Negro State Forest has been identified by the U.S. Fish and Wildlife Service as an endangered species.

## Flow

The flow of water in the river is controlled by the floodgates at Toa Vaca Lake, located in the municipality of Villalba. Río Inabon has a discharge of 15,000 ft$^3$/s. The Inabón has been known to overflow easily in times of heavy rains. Several rescues have taken place when the river has increased its level rapidly, a phenomenon known as flash flood. Due to its proximity to the eastern end of Aeropuerto Mercedita, the river has affected the operation of the airport in times of heavy rains. This was the case with the hurricane Maria in September 2017.
* Bridge over Río Inabón on PR-1 between Ponce and Santa Isabel in 1920.

### Course of the river

The following table summarizes the course of Río Inabón in terms of roads crossed. Roads are listed as the river flows from its origin in the mountains of Barrio Anón, north of the city of Ponce, to the Caribbean Sea in the south (N/A = Data not available):
| No. | Barrio | Road | Road's km marker | NBI ID | Bridge name (if any) | Direction (of bridge traffic) | Coordinates | Notes |
| 1 | Anón | Unnamed | not marked | 23401 | Unnamed | Both | 18°7′55.8114″N 66°34′47.244″W﻿ / ﻿18.132169833°N 66.57979000°W﻿ / 18.132169833; -66.57979000 | 0.1 km East of PR-511, km 12.7, on Unnamed Road* |
| 2 | Anón | PR-511 | 12.5* | 27031 | Unnamed | Both | 18°7′28.524″N 66°34′41.484″W﻿ / ﻿18.12459000°N 66.57819000°W﻿ / 18.12459000; -66.57819000 | 0.3 km North of Calle Guarayo |
| 3 | Anón | Unnamed | not marked | 29441 | Unnamed | Both | 18°7′20.1″N 66°34′39.54″W﻿ / ﻿18.122250°N 66.5776500°W﻿ / 18.122250; -66.5776500 | 0.1 km West of PR-511, km 12.7, on Unnamed Road (0.1 km north of Calle Guayaro)* |
| 4 | Anón | PR-511 | 11.7* | 29421 | Unnamed | Both | 18°7′15.1674″N 66°34′18.2994″W﻿ / ﻿18.120879833°N 66.571749833°W﻿ / 18.120879833; -66.571749833 | 0.1 km South of Camino Rosaly. (From this point southward, Río Inabón runs on the west side of PR-511) |
| 5 | Real | Calle Sector Jurutungo | not marked | 29431 | Unnamed | Both | 18°5′52.3674″N 66°33′48.8514″W﻿ / ﻿18.097879833°N 66.563569833°W﻿ / 18.097879833; -66.563569833 | At Charca Puente del Agua, 0.1 km West of PR-511, km 12.65, on Camino Sector Jurutungo; 0.3 km North of Capilla Catolica San Martin* |
| 6 | Coto Laurel | PR-14 | 9.8 | 22041 | Unnamed | Both | 18°3′0.4314″N 66°32′41.4594″W﻿ / ﻿18.050119833°N 66.544849833°W﻿ / 18.050119833; -66.544849833 | 0.5 km NE of Barrio Coto Laurel; 0.1 km west of INT PR-14 & PR-511. |
| 7 | Sabana Llana | PR-52 | 94.3 | N/A | Unnamed | Southbound | 18°2′23.136″N 66°32′15.072″W﻿ / ﻿18.03976000°N 66.53752000°W﻿ / 18.03976000; -66.53752000 | PR-52 SB in Municipality of Juana Diaz |
| 8 | Sabana Llana | PR-52 | 94.3 | N/A | Unnamed | Northbound | 18°2′22.416″N 66°32′14.64″W﻿ / ﻿18.03956000°N 66.5374000°W﻿ / 18.03956000; -66.5374000 | PR-52 NB in Municipality of Juana Diaz |
| 9 | Sabana Llana | C. Ramal/Av. San Cristobal | N/A | 25141 | Unnamed | Both | 18°2′19.9314″N 66°32′14.172″W﻿ / ﻿18.038869833°N 66.53727000°W﻿ / 18.038869833; -66.53727000 | Calle Ramal (Calle Laredo) is accessible via Ave. San Cristobal located behind Hospital San Cristobal; Bridge is parallel to the PR-52 km 94.3, bridges |
| 10 | Capitanejo, Vayas | PR-1 | 120.4 | 251 | Unnamed | Both | 18°0′14.796″N 66°33′12.132″W﻿ / ﻿18.00411000°N 66.55337000°W﻿ / 18.00411000; -66.55337000 | 0.1 km west of PR-507, Ponce, immediately east of Aeropuerto Mercedita (6.5 km E of Ponce). Bridge has Ponce's Barrio Vayas to its west and Juana Diaz's Barrio Capitanejo to its east. |
* *Marker requires field verification.