The Suvarnavathi River, also called the Honnuhole or Honhole river, is a  southern tributary of the Kaveri River in the Indian states of Karnataka and Tamil Nadu.  Its drainage area is about .
The river begins at Badibadga in the Nasurghat hills of southern Karnataka's Mysore district as the convergence of two streams, the Niredurgihalla and Araikaduhalla.  It is joined by two significant tributaries, the Chikkahole and the Yenehole, on its journey, generally to the east, to the Kaveri.

The Suvarnavathi Reservoir, entirely in Karnataka, is formed by the Suvarnavathi Dam  built across the river. The dam is adjacent to the Karnataka State Forest near Punajanur along the border between Karnataka and Tamil Nadu.

The Suvarnavathi Dam is located near the village of Attugulipura, Chamarajanagara District, Karnataka, India. It is adjacent to National Highway 948, and is about  from Chamarajanagara, a town of about 70,000 (as of 2011) which is headquarters of the district.  The reservoir was built in 1977 on the National Highway 948 between Bengaluru and Coimbatore.  Suvarnavathi reservoir has a storage capacity of 1258.78 Tmcft.  It was constructed at a cost of about ₹ 299.60 lakhs in 1977.  The length of the dam is .  Its height is 25 m (above the river bed level).

In 2019, it was believed that the twin reservoirs could go dry.  In addition to the effect of general drought, this was du to the fact that Tamil Nadu had quietly pursued a program to build dozens of small dams in villages upstream from the reservoirs (villages including Kodipura, Thalamali, Nithapura, Egalur, Chikkahalli, Marur, Malajanapura) to preserve water for their use.  Previously, a heavy rainfall in the Talwandi catchment area in Tamil Nadu would reach and fill the Chikkahole reservoir, and overflow from there would also raise the level of the Suvarnavathi reservoir.  In 2019 however "despite good rainfall for a couple of weeks in Tamil Nadu, not a drop has flown into Chikkahole reservoir."

An analysis published in 2022 assesses the dam's spillway capacity to be inadequate, and that a height increase of the dam is needed, else 46 villages and a city are at undue risk of flooding, which will be prohibitively expensive if it occurs.

About  away is Chikkahole Reservoir, created by the Chikkahole Dam, which is linked to the Suvarnavathi Reservoir by a channel.  The Suvarnavathi and Chikkahole are called twin reservoirs. Both of them are in the back drop of beautiful nature. Fisheries and horticulture are the main occupation of this area. The added attraction of these reservoirs are seen in the wandering of wildlife all around. 

The Suvarnavathi Reservoir is the main source of water for irrigation in nearby villages; it usually is full by end of the monsoon season and dry during summer season.  The main source of water for the reservoir is rainfall in the Punanjanur (Punajur) forest area during the monsoon. Also it is the source of drinking water for wild animals as it is adjacent to the thick forest.

Accessibility 
Numerous bus and train services provide transportation from Bangalore to the town Chamarajanagara town, and then it is around  further to the Suvarnavathi Dam.  Local transport bus service is available for the last leg.

See also
Nearby attractions include:

Bandipura Reserve Forest
Bhavanisagar Dam
Biligiriranga Hills

Gaganachukki and Barachukki Falls
Male Mahadeswara Hill
Satyamangalam

References 

Rivers of Karnataka
Rivers of Tamil Nadu
Geography of Chamarajanagar district
Tourist attractions in Chamarajanagar district