Afternoon showers replenish city rivers, more rain forecast for the weekend

Hydrologists at ETAPA, Cuenca’s public utility company, say the city’s reservoirs are filling up, thanks to recent rainfall.

Cuenca’s water supply depends on the flow rate of its four rivers.

On Monday, ETAPA issued a statement advising water customers to cut back on usage, warning that restrictions could be imposed due to low levels at city reservoirs. They said that the flow of local rivers, which feed the reservoirs had fallen to near-record low flow rates. The Tomebamba River, the largest of the rivers, was flowing at only 4% of its normal rate on Monday afternoon.

On Friday, ETAPA reported that rainfall that began Tuesday afternoon has replenished the rivers and that reservoir levels were rising.

According to University of Cuenca hydrologist Kevin Sanchez, the rivers that supply the city’s reservoirs have unique characteristics that make planning difficult for water utilities such as ETAPA.

“Because the South American continental divide is only 17 miles from Cuenca, these rivers have a short run and a limited watershed,” he says. “They can rise and fall quickly depending on rainfall in the Cajas Mountains. Most of us who have lived here for any period of time have seen the rivers go from a trickle to a raging torrent within an hour or two when there is heavy rain in the mountains. This makes it tricky to plan for municipal water needs.”

The good news — most of the time — according to Sanchez, is that the Cajas watershed gets plenty of annual rainfall. “Even though Cuenca only receives 38 inches per year, some areas in the Cajas get more than 100. Under normal conditions, the mountain watershed acts as a giant sponge, holding great stores of water that it feed into the Tomebamba, Yanuncay, and other rivers,”

He adds that the sponge has its limits and during prolonged dry periods area rivers are often reduced “to a trickle”.

The national weather office says recent rains, mostly in the form of afternoon showers. will continue through the weekend but drier weather is forecast for next week.