from typing import Dict


def group_production(production: Dict[str, int]) -> Dict[str, int]:
    """Group various types of coal (e.g. lignite, hard coal) and hydro (river, reservoir).

    Args:
        production (Dict[str, int]): Dictionary with production for each resource type.

    Returns:
        Dict[str, int]: Dictionary with production for each resource type.
        Only one entry for various types of coal.
    """
    grouped_prod: Dict[str, int] = {}

    for k, v in production.items():
        if k.startswith('uhli'):
            grouped_prod['uhli'] = grouped_prod.setdefault('uhli', 0) + v
        elif k.startswith('voda'):
            grouped_prod['voda'] = grouped_prod.setdefault('voda', 0) + v
        else:
            grouped_prod[k] = v

    return grouped_prod