(a) 
The City is hereby divided into zoning districts, as specified hereinafter.
(b) 
Within each district there shall be uniform regulation of use of buildings, structure and land, of height, and size of building and structures, of size and width of lots, of dimensions of yard and other open spaces, and of other requirements, as provided in this Zoning Ordinance.
(c) 
Every parcel of land and every building or other structure in the City, except as otherwise provided by law or by this Zoning Ordinance shall be subject to the regulations, restrictions, and requirements specified for the District in which it is located.
For the purposes of this Zoning Ordinance, the City is hereby divided into the following use districts:
(a) 
Residence Districts.
S - Single Family: S-10 and S-6
T - Two Family
SC - Single Family Conversion
R - Residential multi-family: R.75 and R1.2
CR - Cluster Residential
(b) 
Business Districts.
NB - Neighborhood Business
LB - Limited Business
(c) 
Industrial Districts.
I-1 - Industrial 1
I-2 - Industrial 2
I-3 - Industrial 3
(d) 
Special Zoning Districts.
ALOD - Assisted Living Overlay District
AODD - Arsenal Overlay Development District
NMU - Neighborhood Mixed Use
OSC - Open Space and Conservancy
RD - Limited Redevelopment District
R/SOD - Religious/School Building Overlay District
PSCD - Pleasant Street Corridor District
RMUD - Regional Mixed Use District
TODO - Transit Oriented Development Overlay District
WSQ1 - Watertown Square 1
WSQ2 - Watertown Square 2
WSQ3 - Watertown Square 3
(a) 
The location and boundaries of these districts are hereby established as shown on a map entitled "Zoning Map of Watertown, Massachusetts," as dated November 14, 2024, and on file in the office of the City Clerk, which map, with all explanatory matter thereon, is declared to be a part of this Zoning Ordinance.
(b) 
Any change in the location or boundaries of a district hereafter made through the amendments of the Zoning Ordinance shall be indicated by the alteration of the Zoning Map, and the Zoning Map thus altered is declared to be part of the Zoning Ordinance thus amended.
(c) 
Where a district boundary is indicated as approximately following, or parallel to, the center line or street line of a street, highway, railroad right of way, or water course, such a district boundary shall be construed as following, or as being parallel to, such center line or street line. Where a district boundary is indicated as approximately following a lot line, such line shall be construed to be said boundary. When any uncertainty exists as to the exact location of a boundary line, the location of such line shall be determined by the Planning Board.
(d) 
When a lot in one ownership is situated in part in the City of Watertown and in part in an adjacent city or town, the regulation and restriction of the Zoning Ordinance shall be applied to that portion of such lot as lies in the City of Watertown in the same manner as if the entire lot were situated therein.