16 USC 2203 – Emergency watershed program
(a) In general
The Secretary is authorized to undertake emergency watershed protection measures, including the purchase of floodplain easements, for runoff retardation and soil-erosion prevention, in cooperation with landowners and land users, as the Secretary deems necessary to safeguard lives and property from floods, drought, and the products of erosion on any watershed whenever fire, flood, or any other natural occurrence is causing or has caused a sudden impairment of that watershed.
(b) Floodplain easements
(1) Modification and termination
The Secretary may modify or terminate a floodplain easement administered by the Secretary under this section if—
(A) the current owner agrees to the modification or termination; and
(B) the Secretary determines that the modification or termination—
(i) will address a compelling public need for which there is no practicable alternative; and
(ii) is in the public interest.
(2) Consideration
(A) Termination
As consideration for termination of an easement and associated agreements under paragraph (1), the Secretary shall enter into compensatory arrangements as determined to be appropriate by the Secretary.
(B) Modification
In the case of a modification under paragraph (1)—
(i) as a condition of the modification, the current owner shall enter into a compensatory arrangement (as determined to be appropriate by the Secretary) to incur the costs of modification; and
(ii) the Secretary shall ensure that—
(I) the modification will not adversely affect the floodplain functions and values for which the easement was acquired;
(II) any adverse impacts will be mitigated by enrollment and restoration of other land that provides greater floodplain functions and values at no additional cost to the Federal Government; and
(III) the modification will result in equal or greater environmental and economic values to the United States.