§ 299-y. Certain powers of board of supervisors and soil conservation districts not affected. Nothing in this article contained shall be deemed to repeal, amend or modify the powers of the board of supervisors as provided by section two hundred twenty-three of this chapter in relation to flood control and soil conservation. Nothing in this article contained shall be deemed to repeal the authority of a soil conservation district to undertake any works or measures as authorized by the soil conservation districts law, provided that federal financial aid pursuant to the said "Watershed Protection and Flood Prevention Act" is neither sought nor required in constructing and carrying out such works or measures.