Any special improvement district formed pursuant to this chapter shall be under the supervision, direction and control of the board of directors of the water conservation district, unless proceedings are taken under this article for the election of a board of trustees for such special improvement district, in which event such special improvement district shall be under the supervision, direction and control of such board of trustees. Such directors or trustees, as the case may be, shall have the same power, authority and jurisdiction over and with reference to the special improvement district that the board of directors possesses over and with reference to the water conservation district and improvements made within and chargeable to the entire conservation district provided that any obligation created in behalf of a special improvement district shall be a charge against only the properties situated within such special improvement district. All provisions of this division, insofar as they are applicable, including all provisions relating to bonds and assessments, shall apply to and govern special improvement districts formed under this chapter.