nˌɑːnsˈʌtʃ pˈɑːɹk ænd ðə mˈænʃən hɐvbɪn mˈænɪdʒd baɪ ˈɛpsəm ænd sˈʌʔn̩ kˈaʊnsəlz θɹuː ɐ dʒˈɔɪnt mˈænɪdʒmənt kəmˈɪɾi dʒˌeɪˌɛmsˈiː sˈɪns ðə lˈænd wʌz pˈɜːtʃɪst baɪ fˈoːɹ kˈaʊnsəlz ɪn nˈaɪntiːnhˈʌndɹɪd θˈɜːɾi sˈɛvən tə sˈeɪv ɪt fɹʌm dɪvˈɛləpmənt æz pˈɑːɹt ʌvðɪ ɪstˈæblɪʃmənt ʌvðə mˌɛtɹəpˈɑːlɪtən ɡɹˈiːn bˈɛlt.
Nonsuch Park and the Mansion have been managed by Epsom and Sutton Councils through a joint management committee (JMC) since the land was purchased by four councils in 1937 to save it from development as part of the establishment of the Metropolitan Green Belt.