Class: III; Ave. Gradient: 7 m/km; Portages: none; Length: up to 33km; Time: up to 5 hours
Season: mid-June to October; rafts? yes; Highlights: big-water rafting; Crux Move: picking your TO
Water Quality: poor; Water Temperature:warm
PI: Puente Amatenango (elev.: 850m); TO: Frontera Comalapa (or above)
Description: (click here for general notes about my descriptions)
The Río Cuilco, aka the upper Grijalva, is the final free-flowing stretch of whitewater before it enters a series of dams and reservoirs on the lower Grijalva, Chiapas' mammoth engineering project. (A whole lot more whitewater lies upstream in Guatemala, described here.) The river was the scene of massive flooding in 2005 during Hurricane Stan, and left a wide bare riverbed that is now starting to grow back in.
The river is mostly wide with open class II/III and provides some big-water fun in the heart of the rainy season (agricultural pumping and diverting keep the flows modest at other times). There are no large drops and normally no out-of-boat scoating is necessary. Besides navigating the braided channels at several points, the main challenge is the narrow gorge at Comalapa. This gorge is 500m long, with the Chicomuselo road bridge at the mid-point (worth a pre-run scout). The gorge is cliffed-in and has a couple pushy rocky drops so proceed with caution.
The top PI is at the Puente Amatenango on the Comapala-Motozintla highway. The bottom TO is at Frontera Comalapa, 800m after fully exiting the Comalapa gorge, on a rocky beach river-right along a 400m-long 180-degree right curve. Since the run is road-side, you have many options for shortening the trip. The most obvious spots for PI/TO are a series of 5 car and hammock bridges in the Guerrero area starting at river km 14 and ending at river km 24 (I don't know the names of the bridges; the road directions are mentioned below).
Flash Flood Danger: normal.
Descent History: I have read reports suggesting that Vladimir Kovalik of Wilderness World may have run this stretch back in the 70's. Otherwise the only other descent I know about was with an Aventuras Tropicales raft group led by Alejandro Giordano (and me in a kayak) in September 2002.
Flow Notes: There is an on-line gage downstream at San Miguel (below the confluence with the Río Independencia), linked to below. My impressions are with 2500 cfs. Here I also show historical data near the TO from INEGI:
click here for the height graph
Shuttle Notes: Puente Amatenango is about 35 km south of Frontera Comalapa on the way to Motozintla. The road from Comalapa stays close to the river and there are many suitable access points along the way, especially in the area around Guerrero where there are 5 bridges starting at 1.5 km north of the Guerrero bridge (the most downstream, a hammock bridge) to 7.5 km south of the Guerrero bridge (the most upstream, a car bridge). To get to the lower TO in Comalapa, find the western extension of 8a Avenida Sur Poniente and follow it down to the river.
For those without a car, there are frequent mini-buses travelling the highway to/from Frontera Comalapa but not all are keen on taking kayaks. From the lower TO it's a 2 km-long walk uphill to the town center.
Accommodations: Frontera Comalapa has several budget hotel options.
Nearby Tourist Attractions: There are not so many in this area.