Zoning Districts are established in the Zoning Regulations to promote compatible land use patterns and to establish site development regulations appropriate to the purposes and specific nature of each district.

   The following base districts and overlay districts are hereby established. These districts correspond to the Land Use Districts established by the Denison Comprehensive Plan.

 

 

   A base district designation shall apply to each lot or site within the City and its planning jurisdiction. A site must be in one base district. Overlay and special districts may be applied to any lot or site or any portion thereof, in addition to a base district designation.

   References in the Zoning Ordinance to less intensive or more intensively urbanized districts shall be deemed to refer to those agricultural, residential, commercial, and industrial base zoning districts established in Section 167.02, and shall represent a progression from the AG Agricultural District as the least intensively urbanized to the I-2 General Industrial District as the most intensively urbanized.

   For each Zoning District, permitted uses are set forth in the Use Matrix. Individual sections describe the purpose and specific development regulations for each zoning district. Supplemental Regulations may affect specific land uses or development regulations in each zoning district. The applicable Supplemental Regulations are noted in Use Matrix.

      1.   Adoption of Zoning Map. Boundaries of zoning districts established by this Zoning Regulations shall be shown on the Zoning Map maintained by the City Clerk. This map shall bear the signature of the Mayor attested by the City Clerk under the certification that this is the Official Zoning Map referred to by this Ordinance. This map, together with all legends, references, symbols, boundaries, and other information, shall be adopted as a part of, and concurrent with these regulations. Said Zoning Map shall be on file with the City Clerk and shall be readily accessible to the public at Denison City Hall.

      2.   Changes to the Zoning Map. The City Council may from time to time adopt a new official zoning map which shall supersede the prior official zoning map, in the event that the official zoning map becomes damaged or destroyed; or for purposes of clarity due to a number of boundary changes, or to correct drafting errors or omissions; provided, however, that any such adoption shall not have the effect of amending the original Zoning Ordinance or any subsequent amendment thereof. 7

   The following rules shall apply in determining the boundaries of any zoning district shown on the Zoning Map.

      1.   Where district boundaries are indicated as approximately following lot lines, such lot lines shall be considered the district boundaries.

      2.   Where district boundaries are indicated as within street or alley, railroad, streams or creeks, or other identifiable rights-of-way, the centerline of such rights-of-way shall be deemed the district boundary.

      3.   Where a district boundary divides a property, the location of the boundary shall be determined by the use of the scale appearing on the Zoning Map.

      4.   Where district boundaries are indicated as approximately following corporate limits, such corporate limits shall be considered the district boundaries.

      5.   Where district boundaries are indicated as approximately following section lines, quarter section lines, or quarter-quarter section lines, such lines shall be considered the district boundaries.

      6.   Boundaries not capable of being determined as set forth in 1 through 5 shall be as dimensioned on the official Zoning Map or if not dimensioned shall be determined by the scale shown on the map.

   Whenever a public street or alley is vacated, the zoning district adjoining each side of such right-of-way shall be extended out to the former centerline.

   All unimproved or agricultural territory that may hereafter be annexed to the City shall be considered as lying in the AG Agricultural/Urban Reserve District until such classification shall be changed as provided by this ordinance. Any improved property that is annexed into the city shall be zoned according to the zoning district that most nearly describes either its present use or the use proposed by Denison’s Comprehensive Development Plan. This zoning shall be established by the Planning Commission and the City Council at the time of annexation.

   Except as specified in this chapter, no building or structure shall be erected, converted, enlarged, reconstructed or structurally altered, nor shall any building or land be used, which does not comply with all of the district regulations established by this chapter for the district in which the building or land is located.

   No lot shall contain any building used in whole or in part for residence purposes unless such lot abuts for at least twenty feet on at least one public street, or unless it has an exclusive unobstructed private easement of access or right-of-way of at least twenty feet wide to a street; and there shall be not more than one single-family dwelling for such frontage or easement, except that a common easement of access at least fifty feet wide may be provided for two or more such single-family dwellings or for one or more two-family or multiple dwellings.

   Within zoning districts in Denison, different uses are permitted with different conditions. These are displayed in the Use Matrix. Levels of permission include:

      1.   Uses Which are Permitted by Right. These uses are permitted subject to issuance of a building permit by the Building Official, subject only to compliance with all regulations of this ordinance. Uses permitted by right might be subject to supplemental regulations contained in this ordinance. These uses are indicated in the Use Matrix by a “P” in the applicable cell.

      2.   Special Uses. These uses are subject to approval of a Special Use Permit by the Zoning Board of Adjustment, following the procedure set forth in Section 174.11. These uses are indicated in the Use Matrix by a “S” in the applicable cell.

      3.   Site Plan Approval. Some use types require an additional site plan approval by the Zoning Administrator/Building Official, based on specific criteria for review. This procedure is set forth in Section 174.06. These uses are indicated in the Use Matrix by an asterisk (*) following the citing of a specific use type.

   The regulators set forth in the tables in Sections 167.14 through 167.30. establish the limits and requirements for most development in the City of Denison and its extra-territorial jurisdiction. This section is intended to provide guidance for applying the regulators contained in these tables.

      1.   Site Area per Housing Unit. This indicates the gross land area per unit within a residential development. For example, a 40-lot subdivision on a 10-acre (435,600 square foot tract) will have a site area per unit of 10,890 square feet. Site area per unit, which measures gross density, may differ from minimum lot size. In conservation development, the site area per unit will be larger than minimum lot size, permitting the clustering of lots in exchange for common open space. In multi-family development, the site area per unit will usually be smaller than minimum lot size, because the lot is the legal parcel on which a multiple-unit building is built.

      2.   Minimum Lot Area. This indicates the minimum size of a legally described and recorded parcel upon which development can take place. As noted above, minimum lot area and site area per unit may not be the same.

      3.   Minimum Lot Width. This is the required minimum distance connecting at points along opposite side lot lines, measured at the required front yard setback. For example, the lot width of an irregular lot in a district requiring a 25-foot front yard setback is determined by:

         A.   Locating the points along each side lot line at a distance of 25 feet back from the front property line.

         B.   Drawing a line connecting these two points.

         C.   Measuring the length of this line. The length is the lot width.

      4.   Minimum Yards. These define the required setbacks of buildings from front, side, and rear property lines. While the yard requirements apply to a majority of development, the ordinance provides for a number of exceptions. Some of these include:

         A.   Planned Developments. Front yard setbacks can be varied within Planned Developments, which are reviewed and approved by the City Council after a recommendation from the Planning Commission.

         B.   Major Streets. The City may require greater than normal setbacks along segments of the City’s arterial street system, as defined in the comprehensive development plan.

         C.   Flexibility Provided by Supplemental Development Regulations. Section 170.04 establishes supplemental regulations, many of which provide flexibility or variations in setback regulations for specific contexts.

         D.   Maximum Setbacks. Some specific zoning districts provide maximum as well as minimum setbacks. These setbacks establish “build-to” lines that may be necessary to protect the appearance and character of special urban districts.

      5.   Maximum Height. Height normally measures the vertical distance from the established grade to the highest point of a building. However, as established by the definition of height, the point of measurement may vary for different types of buildings and roof slopes.

      6.   Maximum Building Coverage. This measures the percentage of a site that may be covered by the footprint of buildings. Thus, a 20,000 square foot building on a 40,000 square foot site has a building coverage of 50%. This is a method of regulating the scale of buildings in an area.

      7.   Maximum Impervious Coverage. This measures the percentage of a site that may be covered by buildings and other surfaces and development features which prevent the penetration of water into the ground (such as driveways, porches, parking lots, and other features). Limits on impervious coverage help control the velocity and quantity of storm water runoff and provide for groundwater recharge.

      8.   Floor Area Ratio. Just as site area per unit controls the density of residential development, floor area ration (FAR) controls the density of non-residential development. FAR is the ratio of gross floor area of a building to total site area. Thus, in an area with a maximum permitted FAR of 1.0, a 40,000 square foot building may be located on a 40,000 square foot site. Naturally, because of coverage ratios, landscaping, and parking requirements, such a building will be multi-story.

      9.    Maximum Amount of Total Parking in Street Yard. This controls the maximum amount of parking that can be located in the area between a building facade and the street. When applied in certain zoning districts, it is intended to reduce the number of cars seen from the street, encourage site planning which locates parking in rear and side yards, and produce a stronger relationship between buildings and streets. For example, a project with 100 parking stalls and a 50% limit on the amount of parking located in street yards must locate 50 of its stalls in rear or side yards without street exposure.

      10.   Minimum Depth of Landscaping Adjacent to Street Right-of-Ways. This establishes the depth of landscaping that must be provided on private property adjacent and in from the right-of-way line. Thus, if the required minimum depth is fifteen feet, a project must landscape the first fifteen feet of its site back from the right-of-way line. All landscaping must be done in accordance with Chapter 171, establishing landscaping standards.

      11.   Minimum Buffer Yard Requirements. This establishes the depth of a buffer yard that must be provided by intensive land uses adjacent to primarily residential land uses in residential zoning districts. All landscaping must be done in accordance with Chapter 171, establishing landscaping standards.

      12.   Supplemental Use Regulations. Certain permitted uses require satisfaction of specific requirements in order to function successfully in their urban or rural contexts. These supplemental requirements are set forth in Chapter 169. These requirements are cross-referenced in the “Supplementary Regulations” column of the Use Matrix.