§ 151.43 DESIGN CRITERIA FOR NEW CONSERVATION SUBDIVISIONS AND PUDS.
   (A)   Minimum size. All developments must contain at least three contiguous acres of buildable area with a lot width of 400 feet.
   (B)   Buffer.
      (1)   A 50-foot vegetative buffer will be maintained or established along the boundary of the PUD. There shall be no units or impervious coverage within this buffer with the exception of access roads or utilities. The buffer will serve to screen the adjacent parcels and the lake, where applicable, from the units within the PUD. The screening will contain both low growing (e.g., brush) and high growing (e.g., trees) vegetation.
      (2)   Adjacent parcels and the lake, where applicable, shall be a minimum of 50% screened, as measured by the Planning and Zoning Administrator, from the adjacent parcel or the lake during leaf-on conditions. An earthen berm may be used where, in the opinion of the Planning Commission, the existing vegetation cannot be enhanced to meet the 50% screening criteria. Use of a berm shall not preclude the maintaining of a 50-foot buffer or the installation of screening as part of the berm.
   (C)   Minimum structure setbacks.
 
Shoreland Class Ordinary High Water Level Structure
Setback (Feet)
General development
120
Natural environment
200
Recreational development
150
 
   (D)   Common open space. At least 50% of the total project area must be permanently preserved as common open space. Common open space must include areas with physical characteristics unsuitable for development in their natural state, and areas containing significant historic sites or unplatted cemeteries, and at least 75% of the common open space must be upland area. At least 33% of the common open space shall be retained in a contiguous area.
      (1)   The land area of all dwelling units/sites and accessory structures, the space between buildings in a cluster, an area of 25 feet around each structure, all road rights-of-way, and all land covered by impervious surfaces, road surfaces, parking areas, or structures, shall not be included in the computation of common open space.
      (2)   Common open space may include any outdoor recreational facilities for use by owners of the dwelling units or sites, or the public.
      (3)   Common open space may include areas used for storm water retention or management and areas used for sanitary sewer collection or disposal. Where common space includes sanitary sewage treatment systems, the use of the space shall be restricted where necessary to avoid adverse impacts on the systems.
      (4)   All of the shore impact zones must be included as common open space.
      (5)   Common open space must not include commercial facilities or uses, but may contain water-oriented facilities.
      (6)   The appearance and use of common space areas, including topography, vegetation, and allowable uses, must be preserved by use of restrictive deed covenants, permanent easements, public dedication and acceptance, or other equally effective and permanent means acceptable to the city.
   (E)   Sanitary sewer and water supply standards.
      (1)   Planned unit developments shall be connected to publicly owned water supply and sewer systems, if available. On-site water supply and sewage treatment systems must be centralized and designed and installed to meet or exceed applicable standards or rules of the state’s Department of Health and the state’s Pollution Control Agency. On-site sewage treatment systems must be located on the most suitable areas of the development, and sufficient area free of limiting factors must be provided for a replacement standard soil treatment system for each sewage system.
      (2)   Conservation subdivisions shall be connected to publicly owned water supply and sewer systems, if available. Where publicly owned water supply and sewer systems are not available, conservation subdivisions shall either establish dedicated areas for individual sewage treatment systems or establish centralized water supply and sewage treatment systems to serve the entire subdivision.
   (F)   Erosion control and storm water management. Erosion control and storm water management for developments must meet the standards in the City of Crosby Stormwater Ordinance 2016-06. For planned unit developments, the impervious surface coverage shall not exceed 15% in either the total project area or the first tier. For conservation subdivisions, the impervious surface coverage for lots must meet the standards in § 154.034. Erosion control and storm water management shall be designed by certified personnel in erosion and sediment control using the best management practices found in the latest Pollution Control Agency’s Storm Water Best Management Practices Manual, approved by the local government, and effectively implemented.
      (1)   For post construction storm water management, when possible, existing natural drainage ways, wetlands, and vegetated soil surfaces must be used to convey, store, filter, and retain storm water runoff before discharge to public waters. When development density, topographic features, and soil and vegetation conditions are not sufficient to adequately handle storm water runoff using natural features and vegetation, various types of constructed facilities such as diversions, settling basins, skimming devices, dikes, waterways, and ponds may be used. Preference must be given to designs using surface drainage, vegetated filter strips, bioretention areas, rainwater gardens, enhanced swales, offline retention areas, and natural depressions for infiltration rather than buried pipes and human-made materials and facilities.
      (2)   Development must be planned and conducted in a manner that will minimize the extent of disturbed areas, runoff velocities, erosion potential, and reduce and delay runoff volumes. Erosion prevention and sediment control practices must be used to retain sediment on site. Disturbed soil areas must be stabilized and protected as soon as possible. The maximum time the soil in a project area can remain exposed when the area is not actively being worked is three days. Temporary or permanent cover for the exposed areas is required at that time but should be installed sooner if possible. All deltas and sediment deposited in surface waters, including drainage ways, catch basins, and other drainage systems must be removed within 14 days unless precluded by legal, regulatory, or physical access restraints. The areas where sediment removal results in exposed soil must be stabilized within seven days after completing the removal.
      (3)   To the maximum extent possible, land-disturbing activities must not occur within the shore impact zone.
      (4)   Impervious surface coverage.
 
Development or Use
Class or District
Coverage (Percent of Applicable Area)
Applicable Area
Conservation subdivision
General development and recreational development
15
Riparian lots
Natural environment, special protection, sensitive area and all river classes
12
Riparian lots
All classes and districts
35
Nonriparian lots
Planned unit developments
All classes and districts
15
Total project area and first tier
 
   (G)   Exterior lighting. All exterior lighting shall be directed downward. Lighting shall not illuminate parcels adjacent to the development, either directly or indirectly.
   (H)   Shore recreation facilities.
      (1)   Shore recreation facilities, including, but not limited to, swimming areas, docks, and watercraft mooring areas and launching ramps, must be centralized and located in areas suitable for them. Evaluation of suitability must include consideration of land slope, water depth, vegetation, soils, depth to ground water and bedrock, or other relevant factors.
      (2)   No more than 20% of the shore impact zone shall be used for shore recreation facilities.
      (3)   The number of spaces provided for continuous beaching, mooring, or docking of watercraft shall not exceed one for each first-tier unit that would be allowed as calculated in § 151.46(A). The number may be reduced based on the suitability of the site.
      (4)   Facilities for mooring of individual watercraft, including boat lifts and canopies, shall be earth-tone in color and shall be positioned so as to minimize their visibility from the lake. Canopies may be disallowed if they would have a strong visual presence.
   (I)   Building standards. Units must be clustered in one or more groups and located on suitable areas of the development. All structures within a PUD must meet the minimum standards:
      (1)   New multi-family dwellings of four units or larger shall be designed by an architect;
      (2)   New multi-family buildings shall meet the state code for fire and sound ratings;
      (3)   Water systems must be winterized;
      (4)   Parking and driving areas must be paved; and
      (5)   All buildings shall be earth tone in color and shall be designed, constructed, and positioned to be compatible, in color, character, and mass, with the surrounding land use.
(Ord. 2016-03, passed - -)