[4] Per Japanese census data,[5] the population of Nishiwaga has declined over the past 60 years and is now less than half of what it was a century ago.

Waga District was under the control of the Nanbu clan of Morioka Domain during the Edo period.

Nishiwaga has a mayor-council form of government with a directly elected mayor and a unicameral town council of 12 members.

In terms of national politics, the town is part of Iwate 3rd district of the lower house of the Diet of Japan.

There are several natural hot springs baths operated by the municipality, and inexpensive monthly passes are available to residents.

Many traditional bed and breakfast inns operate in these areas, usually with their own private hot spring facilities, some of which are open to day visitors for a fee.