Any sanitary district organized under this Act which heretofore has or may hereafter use any navigable stream or river for a portion of its channel, or as an adjunct thereto or auxiliary to its main channel, may for the purpose of widening, deepening or improving the same, for purposes set forth in this Act, acquire by purchase, or under and pursuant to the eminent domain laws of this state, or otherwise, sufficient land for the purpose of making such improvement by widening and deepening said stream, as aforesaid.
70 ILCS 2605/35