ðə ɹˈiːzən ˌʌnɪmpˈɛɹd ɹˈʌnɔf ɪz ɪmpˈoːɹtənt ɪz bɪkˈʌz lˈɔŋtˈɜːm hˌaɪdɹəlˈɑːdʒɪk ɹˈɛkɚdz ɑːɹ ˈɔfən jˈuːzd tə dɪvˈɛləp ɹᵻlˈeɪʃənʃˌɪps bᵻtwˌiːn pɹɪsˌɪpɪtˈeɪʃən, ɹˈʌnɔf, ænd wˈɔːɾɚ səplˈaɪ.
The reason unimpaired runoff is important is because long-term hydrologic records are often used to develop relationships between precipitation, runoff, and water supply.