ˌʌnɪmpˈɛɹd ɹˈʌnɔf kˌælkjʊlˈeɪʃənz ɑːɹ jˈuːzd ɛkstˈɛnsɪvli ɪn wˈɛstɚn juːnˈaɪɾᵻd stˈeɪts stˈeɪts sˈʌtʃ ɐz kˌælɪfˈoːɹniə fɔːɹ wˈɔːɾɚ ɹᵻsˈoːɹsᵻz mˈænɪdʒmənt ˌæplɪkˈeɪʃənz, pɚtˈɪkjʊlɚli ɪnðə kˌælkjʊlˈeɪʃən ʌv wˈɔːɾɚ jˈɪɹ klˌæsɪfɪkˈeɪʃənz ænd ɹˈɪvɚɹ ˈɪndɛksᵻz.
Unimpaired runoff calculations are used extensively in western United States states such as California for water resources management applications, particularly in the calculation of water year classifications and river indexes.