Why do Bhutanese banks have excess deposits at the central bank?

Roughly Nu 60 billion of bank deposits sit at the RMA above the regulatory minimum because the lending environment outside that parking lot is narrow: regulated tourism loans saw 75% on payment holiday at various points, agricultural credit is thin, the housing market is concentrated. Banks default toward parking deposits at the central bank because the alternative — booking loans and carrying credit risk — is less attractive than the modest interest the central bank pays.