heroku pg:backups capture
curl -o latest.dump `heroku pg:backups public-url`
If you didn't create a role for your local database, then do :
createuser -s -r <role_name>
NB : the database name and roles can be found in the `database.yml' file
pg_restore --verbose --clean --no-acl --no-owner -h localhost -U <role_name> -d <database_name> latest.dump
Why do you need to create a role?