The tower provisions of Section 23-435 shall be modified in certain areas, as follows: 

1. In R9D and R10X Districts, the minimum lot coverage of a tower above the maximum base height shall be 33 percent of the lot area of the zoning lot. However, any story located within the highest 15 percent of the tower may cover less than 33 percent of the lot area of a zoning lot provided that the gross area of any such story does not exceed 90 percent of the gross area of that story located directly below the highest 15 percent of the tower. 
2. In R9 or R10 districts without a letter suffix, the following tower-on-a-base provisions shall apply to buildings where: 
   1. more than 25 percent of the floor area is residential; and
   2. such building is located on a zoning lot that fronts upon a wide street and is either within 125 feet from such wide street frontage along the short dimension of a block or within 100 feet from such wide street frontage along the long dimension of the block.
       

                   The minimum lot coverage of a tower above the maximum base height shall be 30 percent of the lot area of the zoning lot. However, any story located within the highest 15 percent of the tower may cover less than 30 percent of the lot area of a zoning lot provided that the gross area of any such story does not exceed 90 percent of the gross area of that story located directly below the highest 15 percent of the tower.
      
      At least 55 percent of the total floor area permitted on the zoning lot shall be located in stories located either partially or entirely below a height of 150 feet. When the lot coverage of the tower portion is less than 40 percent, the required 55 percent of the total floor area distribution, within a height of 150 feet, shall be increased in accordance with the following requirement:

      Percent of lot coverage of the tower portion	Minimum percent of total building floor area distribution below the level of 150 feet
      40.0 or greater	55.0
      39.0 to 39.9	55.5
      38.0 to 38.9	56.0
      37.0 to 37.9	56.5
      36.0 to 36.9	57.0
      35.0 to 35.9	57.5
      34.0 to 34.9	58.0
      33.0 to 33.9	58.5
      32.0 to 32.9	59.0
      31.0 to 31.9	59.5
      30.0 to 30.9	60.0

      
      For the purposes of determining the permitted tower coverage and the required minimum distance between buildings or portions thereof, that portion of a zoning lot located within 125 feet from the wide street frontage along the short dimension of a block shall be treated as if it were a separate zoning lot.
      
      No tower or portion thereof shall be located on a narrow street at a distance that is more than 100 feet from the intersection with a wide street.

3. No towers shall be permitted on any building located wholly or partly in a Residence District, that is within 100 feet of a public park with an area of one acre or more, or a street line opposite such a public park.