Md. Code, Local Gov't § 21-637

(a) In the review and approval by Montgomery County, Prince George’s County, or the City of Takoma Park of the requirements for storm drainage or stormwater management, the county or city may require the owner of land to be developed to: (1) provide easement areas or on–site stormwater management facilities; and (2) agree to construct the necessary facilities or provide for the construction by posting a bond in an amount sufficient to construct the stormwater management facilities that the county or city considers necessary. (b) (1) If the county or the City of Takoma Park decides to construct stormwater management facilities to serve more than one development or if the county or city agrees to allow the owner or developer to construct a stormwater management system, the county or city may enter into an agreement with the developers of new developments for payment by the developers of a fee in lieu of on–site stormwater management facilities. (2) The fee in lieu of on–site stormwater management facilities shall be based on an equitable pro rata share of the net cost of the facilities after deducting any State or federal grants applied to the construction of the facilities. (c) The county or the City of Takoma Park may require the owner’s bond or the contribution of a pro rata share of the net cost for the construction of facilities in adjacent or nearby land in the same drainage area that the county or city may determine will be required because of the development of the owner’s land. (d) Easements required by the county or the City of Takoma Park shall have the restrictions that the county or city may require as to: (1) grading; and (2) prohibiting structures, fences, or plantings on the easement area. (e) (1) The Maryland–National Capital Park and Planning Commission may not approve a plat for subdivision of land until it ascertains from the county, the City of Bowie, or the City of Takoma Park, whichever is appropriate, whether easement areas for stormwater management facilities are required. (2) If easement areas are required, the Maryland–National Capital Park and Planning Commission may not approve the plat for recordation until the easements are included on the plat.