Del. Code tit. 17 § 138
In addition to the powers now vested in the Department for the acquisition of lands or rights therein by virtue of any statute, the Department may, in its discretion, acquire by gift, devise, purchase or in the exercise of the power of eminent domain, acquire by condemnation by proceeding in the manner prescribed in Chapter 61, Title 10, an entire lot, block or tract of land, if by so doing the interest of the public will be best served even though said entire lot, block or tract is not needed for the right-of-way proper, but only if the portion outside the normal right-of-way is landlocked or is so situated so as to give rise to claims or litigation concerning severance or other damage, the cost of acquisition to the State will be practically equivalent to the total value of the whole parcel of land and the parcel remaining is of little value to the owner.
17 Del. C. § 138