Tllat whenever any State or any reclamation, Hood con- t1tig??ii>??dif??1g??i1ri??i$??uil??? trol or draina e district, or other public agency created by any State, ??j;??g,{_<;*,{????g{1g{1jggi1;;?? shall undertalce to secure any land or easement therein, needed in etc. ??? connection with a work of river and harbor improvement duly authorized by Conigress, for the purpose of conveying the same t