A. A Stormwater Treatment Facility is defined by Section 941.01. In all zoning districts except the Downtown Overlay District (DOD), Stormwater Treatment Facilities may be located within the required landscaping areas, frontage greenbelt area, buffer area, parking lot screening area, or landscape islands provided the following criteria are met:
1. Traditional detention/retention ponds are prohibited in the frontage greenbelt.
2. Facilities must be designed to infiltrate to drain dry or have a bottom slope minimum of 1% to drain dry.
3. Side slopes shall have a maximum side slope no more than 3:1 (three units horizontal to one unit vertical).
4. If located within the frontage greenbelt the stormwater treatment facility may only occupy up to 50% of the actual available green space.
i. Footprint of stormwater treatment facility is defined by the top of any slope that is 5:1 or steeper.
ii. Footprint of stormwater treatment facility may cross the greenbelt boundary.
5. Concrete drainage structures must be located to provide maximum benefit for stormwater treatment effectiveness, and must also be mostly concealed within the side slope, and be surrounded by landscape screening rather than visibly protruding into the landscaping.
B. Plantings and ground cover.
The stormwater treatment facility must be planted and landscaped as such:
1. All landscaping requirements of TMC Ch. 1108 - Landscape and Screening must nonetheless be achieved for the frontage greenbelt area, buffer area, parking lot screening area, or landscape islands.
2. Bioretention filter beds must be planted with turf, trees, and/or perennial plant materials chosen from lists provided by the Rain Garden Initiative.
3. Rock is only permitted when designed for dissipation of velocity at locations of concentrated stormwater runoff or for pretreatment considerations according to design guidelines.
4. Side slope shall be grass or sod.
5. Bottom of pond shall be native plants and grasses appropriate for the type of stormwater facility.
i. A list of acceptable native plants may be obtained from the Toledo-Lucas County Rain Garden Initiative.
C. Designs must be approved by DPU, including but not limited to:
1. A maintenance-free outlet.
2. No stone, riprap, concrete or other impervious materials shall be allowed within the stormwater treatment facility unless required by the ODNR Rainwater and Land Development manual and approved by the Division of Engineering Services.
3. Design is according to the State of Ohio Construction General Permit (latest version) and the City Storm Water Management Plan (latest version), both of which include regularly updated design guidance.
D. The stormwater treatment facility shall meet the approval of The City of Toledo's Division of Engineering Services. Facilities not constructed as approved shall be in violation of this code and may also be subject to fees and penalties as set forth in TMC Chapter 941.
E. The landowner, or successors in interest, or agent, if any, or lessee must be jointly responsible for the regular maintenance of the stormwater treatment facility. Stormwater treatment facilities not properly maintained shall be a violation of this code and may also be subject to fees and penalties as set forth in TMC Chapter 941.
F In the Downtown Overlay District, bioretention areas shall be restricted to roof gardens, rear yards and courtyards only.
G. If a stormwater treatment facility alters an approved landscape plan, it shall be resubmitted for the review of the Director of the Planning Commission.
(Ord. 253-09. Passed 4-28-09; Ord. 155-16. Passed 4-26-16.)