The rains which began Saturday night have continued for the past two days and the met department has predicted more thunder showers.
A cloud burst in Rambada has taken place in which 50 people have gone missing, officials said.
The worst hit areas include Rudraprayag and Uttarkashi where the river Mandakini is in spate and the water of the river has entered the market area in Rambada.
While officials refuse to confirm the number of people feared washed away by the rains, local residents say more than two-dozen were washed away in the strong currents.
Following the heavy rains, the Char Dham Yatra has been halted and hundreds and thousands of pilgrims are stranded enroute to Badrinath, Gangotri, Kedarnath and Yamunotri.
"Fearing further rains and possible landslides, the Char Dham Yatra and visit to Hemkunth Saheb has been stopped," an official told IANS.
Troopers of the Indo-Tibetan Border Police (ITBP) have been pressed into service to rescue and evacuate people from Kedarnath and Gaurikund.
Officials said that rivers like Ganga Bhagirathi and Asi Ganga are in spate and the Ganga has breached the danger mark in Haridwar.
Police barriers have been placed in Rishikesh to prevent any further movement of pilgrims on their onward journey to Char Dham.
Met department said the rains in the month of June have since broken a 88-year record. Between Saturday to Sunday, the state capital received 220 mm of rains and by evening 220 mm of rains.
Rains have also halted the movement on the National Highway 58. As many as 123 roads in the Garhwal region have also been blocked, a public works department (PWD) official said.