20-f. Transfer of development rights; definitions; conditions;
 1. As used in this section:
 a. "Development rights" shall mean the rights permitted to a lot,
 parcel, or area of land under a zoning ordinance or local law respecting
 permissible use, area, density, bulk or height of improvements executed
 thereon. Development rights may be calculated and allocated in
 accordance with such factors as area, floor area, floor area ratios,
 density, height limitations, or any other criteria that will effectively
 quantify a value for the development right in a reasonable and uniform
 manner that will carry out the objectives of this section.
 b. "Receiving district" shall mean one or more designated districts or
 areas of land to which development rights generated from one or more
 sending districts may be transferred and in which increased development
 is permitted to occur by reason of such transfer.
 c. "Sending district" shall mean one or more designated districts or
 areas of land in which development rights may be designated for use in
 one or more receiving districts.
 d. "Transfer of development rights" shall mean the process by which
 development rights are transferred from one lot, parcel, or area of land
 in any sending district to another lot, parcel or area of land in one or
 more receiving districts.
 2. In addition to existing powers and authorities to regulate by
 planning or zoning including authorization to provide for transfer of
 development rights pursuant to other enabling law, the legislative body
 of any city is hereby empowered to provide for transfer of development
 rights subject to the conditions hereinafter set forth and such other
 conditions as the city legislative body deems necessary and appropriate
 that are consistent with the purposes of this section, except that in
 cities of over one million any transfer of development rights shall be
 provided in the zoning ordinance after adoption by the city planning
 commission and board of estimate. The purpose of providing for transfer
 of development rights shall be to protect the natural, scenic or
 agricultural qualities of open lands, to enhance sites and areas of
 special character or special historical, cultural, aesthetic or economic
 interest or value and to enable and encourage flexibility of design and
 careful management of land in recognition of land as a basic and
 valuable natural resource. The conditions hereinabove referred to are as
 a. That transfer of development rights, and the sending and receiving
 districts, shall be established in accordance with a well-considered
 plan within the meaning of subdivision twenty-five of section twenty of
 this article. The sending district from which transfer of development
 rights may be authorized shall consist of natural, scenic, recreational,
 agricultural or open land or sites of special historical, cultural,
 aesthetic or economic values sought to be protected. Every receiving
 district, to which transfer of development rights may be authorized,
 shall have been found by the legislative body of the city, after
 evaluating the effects of potential increased development which is
 possible under the transfer of development rights provisions, to contain
 adequate resources, environmental quality and public facilities
 including adequate transportation, water supply, waste disposal and fire
 protection, and that there will be no significant environmentally
 damaging consequences and such increased development is compatible with
 the development otherwise permitted by the city and by the federal,
 state, and county agencies having jurisdiction to approve permissible
 development within the district. A generic environmental impact
 statement pursuant to the provisions of article eight of the
 environmental conservation law shall be prepared by the city for the
 receiving district before any such district, or any sending district, is
 designated, and such statement shall be amended from time to time by the
 city if there are material changes in circumstances. Where a transfer
 of development rights affects districts in two or more school, special
 assessment or tax districts, it may not unreasonably transfer the tax
 burden between the taxpayers of such districts. The receiving and
 sending districts need not be coterminous with zoning districts.
 b. That sending and receiving districts be designated and mapped with
 specificity and the procedure for transfer of development rights be
 specified. Notwithstanding any other provision of law to the contrary,
 environmental quality review pursuant to article eight of the
 environmental conservation law for any action in a receiving district
 that utilizes development rights shall only require information specific
 to the project and site where the action will occur and shall be limited
 to review of the environmental impacts of the action, if any, not
 adequately reviewed in the generic environmental impact statement.
 c. That the burden upon land within a sending district from which
 development rights have been transferred shall be documented by an
 instrument duly executed by the grantor in the form of a conservation
 easement, as defined in title three of article forty-nine of the
 environmental conservation law, which burden upon such land shall be
 enforceable by the appropriate city in addition to any other person or
 entity granted enforcement rights by the terms of the instrument. All
 provisions of law applicable to such conservation easements pursuant to
 such title shall apply with respect to conservation easements hereunder,
 except that the city may adopt standards pertaining to the duration of
 such easements that are more stringent than such standards promulgated
 by the department of environmental conservation pursuant to such title.
 Upon the designation of any sending district, the city shall adopt
 regulations establishing uniform minimum standards for instruments
 creating such easements within the district. No such modification or
 extinguishment of an easement shall diminish or impair development
 rights within any receiving district. Any development right which has
 been transferred by a conservation easement shall be evidenced by a
 certificate of development right which shall be issued by the city to
 the transferee in a form suitable for recording in the registry of deeds
 for the county where the receiving district is situated in the manner of
 other conveyances of interests in land affecting its title.
 d. That within one year after a development right is transferred, the
 assessed valuation placed on the affected properties for real property
 tax purposes shall be adjusted to reflect the transfer. A development
 right which is transferred shall be deemed to be an interest in real
 property and the rights evidenced thereby shall inure to the benefit of
 the transferee, and his heirs, successors and assigns.
 e. That development rights shall be transferred reflecting the normal
 market in land, including sales between owners of property in sending
 and receiving districts, a city may establish a development rights bank
 or such other account in which development rights may be retained and
 sold in the best interest of the city. Cities shall be authorized to
 accept for deposit within the bank gifts, donations, bequests or other
 development rights. All receipts and proceeds from sales of development
 rights sold by the city shall be deposited in a special municipal
 account to be applied against expenditures necessitated by the municipal
 development rights program.
 f. That prior to designation of sending or receiving districts, the
 legislative body of the city shall evaluate the impact of transfer of
 development rights upon the potential development of low or moderate
 income housing lost in sending districts and gained in receiving
 districts and shall find either there is approximate equivalence between
 potential low and moderate housing units lost in the sending district
 and gained in the receiving districts or that the city has or will take
 reasonable action to compensate for any negative impact upon the
 availability or potential development of low or moderate income housing
 caused by the transfer of development rights.
 3. A legislative body of a city modifying its zoning ordinance or
 enacting a local law pursuant to this section shall follow the procedure
 for adopting and amending its zoning ordinance or local laws, as the
 case may be, including all provisions for notice applicable for changes
 or amendments to a zoning ordinance, local law or regulation.
 4. Nothing in this section shall be construed to invalidate any
 provision for transfer of development rights heretofore or hereafter
 adopted by any local legislative body, or, in the case of cities over
 one million, by the board of estimate.