Editor's note(s)—Section 1 of Ord. No. 217, adopted Aug. 22, 1994, repealed former Art. VII, §§ 20-476—20-478 and § 4 of the ordinance enacted a new Art. VII as herein set out in §§ 20-476—20-486. Prior to repeal, former Art. VII pertained to the Shoreland Overlay District and derived from Ord. No. 80, Art. V, § 23, adopted Dec. 15, 1986.
Sec 20-480 Zoning And Water Supply/Sanitary Provisions
- Lot area and width standards. The lot area (in square feet) and lot width standards (in feet) for single, duplex, triplex and quad residential lots created after the date of enactment of this ordinance for the lake and river/stream classification are as follows:
- Sewered lakes—Natural environment:
- Sewered lakes—Recreational development:
Unsewered lakes—Recreational development:
- River/stream lot width standards. There is no minimum lot size requirement for rivers and streams, except those specified in the underlying zoning district. The lot width standards for single, duplex, triplex and quad residential developments for the six river/stream classifications are as follows:
- Additional special provisions. Residential subdivisions with dwelling unit densities exceeding those in the tables in subsections (1), (2) and (3) can only be allowed if designed and approved as residential planned unit developments. Only land above the ordinary high water level of public waters shall be used to meet lot area standards, and lot width standards shall be met at both the ordinary high water level and at the building line. The sewer lot area dimensions in subsections (1), (2) and (3) can only be used if publicly owned sewer system service is available to the property.
(Ord. No. 217, § 4, 8-22-94; Ord. No. 240, § 13, 7-24-95; Ord. No. 240, § 13, 7-24-95; Ord. No. 377, § 54, 5-24-04)
Sec 20-483 Topographic Alterations/Grading And Filling
Connections to public waters. Excavations where the intended purpose is connection to a public water, such as boat slips, canals, lagoons, and harbors, shall be controlled by this ordinance and chapter 7, article III. Permission for excavations may be given only after the commissioner has approved the proposed connection to public waters.
(Ord. No. 217, § 4, 8-22-94; Ord. No. 377, § 59, 5-24-04)
Sec 20-485 Stormwater Management
Lot coverage of lots shall not exceed 25 percent of the lot area, except as follows:
- 30 percent impervious shall be allowed for lots zoned Residential Single Family (RSF) which were platted prior to January 1, 1976 with the following conditions:
- Riparian Lots
- When exceeding 25 percent impervious coverage, riparian lots shall be required to have a shoreline vegetative buffer area equal in size to the new impervious area proposed over 25 percent of the lot area. (Example: 100 square feet of impervious area will require 100 square feet of shoreline vegetative buffer area).
- The shoreline vegetative buffer will be required to encompass at least 25 percent or 20 feet of the linear water frontage, whichever is greater. The buffer width shall be the width necessary to achieve the required buffer area. (For example, 100 square feet of impervious area required with 25 feet of buffer length along the shoreline would require a vegetative buffer width of 4 feet.)
- If the vegetative buffer required is determined to be infeasible by the City Engineer, alternative Best Management Practices (BMPs) shall be installed as outlined in section B.
- Access to the lake for swimming or dock use shall be maintained.
- The vegetative buffer may satisfy the BMP requirement outlined below.
- The following shall be provided at the time of permit application:
- Pre- and post-project lot cover calculations.
- Water Quality Volume shall be calculated by 1.1 inch multiplied by the area in square feet of impervious area over 25 percent.
- BMPs shall be designed to treat the calculated amount of Water Quality Volume created by the proposed impervious area.
- Project plans on a scaled survey shall show the proposed impervious surface as well as the offsetting location and design of BMPs. This could include native vegetative buffers, rain gardens, rain barrels, infiltration/biofiltration basins/swales, etc.)
- An erosion and sediment control plan in accordance with Section 19-145 of the City Code.
- Additional information, such as Hydrologic and Hydraulic Modeling, plans certified by a professional engineer, etc., may be required as determined by the City Engineer when there is reasonable cause for concern of the impacts of the increased stormwater runoff.
- Changes in stormwater runoff shall not cause adverse impacts to adjacent and downstream infrastructure.
- BMPs installed shall be privately owned and may require an Operations and Maintenance Agreement to be recorded against the property at the discretion of the City Engineer.
- Vegetative buffer areas shall be protected in an easement recorded against the property, and monuments shall be installed at the easement boundary
- Non-Riparian Lots
- The following shall be provided at the time of permit application.
- Pre- and post-project lot cover calculations.
- Water Quality Volume shall be calculated by 1.1 inch multiplied by the area in square feet of impervious area over 25 percent.
- BMPs shall be designed to treat the calculated amount of Water Quality Volume created by the proposed impervious area.
- Project plans on a scaled survey shall show the proposed impervious surface as well as the offsetting location and design of BMPs. This could include native vegetative buffers, rain gardens, rain barrels, infiltration/biofiltration basins/swales. etc.
- An erosion and sediment control plan in accordance with Section 19-145 of City Code.
- Additional information such as Hydrologic and Hydraulic Modeling, plans certified by a professional engineer, etc. may be required as determined by the City Engineer when there is reasonable cause for concern of the impacts by the increased stormwater runoff.
- Changes in stormwater runoff shall not cause adverse impacts to adjacent and downstream infrastructure.
- BMPs installed shall be privately owned and may require an Operations and Maintenance Agreement to be recorded against the property.
- 35 percent for medium/high-density residential zones; and
- 70 percent in industrial zones within the Lake Susan Shoreland District.
(Ord. No. 217, § 4, 8-22-94; Ord. No. 628, § 20, 12-11-17)
HISTORY
Amended by Ord. 721 on 1/22/2024
Sec 20-486 Sewage Treatment
Any premises used for human occupancy shall be provided with an adequate method of sewage treatment, as follows:
- On-site sewage treatment systems shall be set back from the ordinary high water level in accordance with the setbacks contained in subsection 20-481(a) of this ordinance.
- A nonconforming sewage treatment system shall be upgraded, at a minimum, at any time a permit or variance of any type is required for any improvement on, or use of, the property. For the purposes of this provision, a sewage treatment system shall not be considered nonconforming if the only deficiency is the sewage treatment system's improper setback from the ordinary high water level.
- The city council has by formal resolution notified the commissioner of its program to identify nonconforming sewage treatment systems. Chanhassen will require upgrading or replacement of any nonconforming system identified by this program within a reasonable period of time that will not exceed three years. Sewage systems installed according to all applicable local shoreland management standards adopted under M.S. § 103F.221, in effect at the time of installation may be considered as conforming unless they are determined to be failing, except that systems using cesspools, leaching pits, seepage pits, or other deep disposal methods, or systems with less soil treatment area separation above groundwater than required by the Minnesota Pollution Control Agency's Chapter 7080 for design of on-site sewage treatment systems, shall be considered nonconforming.
(Ord. No. 217, § 4, 8-22-94; Ord. No. 377, § 60, 5-24-04)