[3][4] Mahadevappa was born on April 20, 1953, in Hadinaru village, Nanjangud taluk, Mysore, Karnataka, to Chikmadaiah and Mahadevamma.

[11] Mahadevappa has engaged in various initiatives aimed at infrastructure development, social welfare, and community empowerment within Karnataka.

[12] During H. C. Mahadevappa's tenure as Minister of the Public Works Department, the Karnataka State Highway Improvement Project (KSHIP) received the iRAP International Award for excellence in road safety initiatives in the Asia-Pacific region.

The award was presented by the Global Road Safety Facility (GRSF) in association with the World Bank (WB).

[13] Mahadevappa contributed to infrastructure development in Karnataka through the following projects: Madhava Mantri Dam, Bengaluru-Mysuru Six-Lane Highway and Dharwad High Court and many more.