20.70.150 OP-01 – Open space standards.
This open space standards (OP) section applies to the following types of development:
SS ST CS CM IP
A. Applicability. The following standards only apply to subdivisions with all resulting lots less than one (1) acre in lot area.
B. Minimum Open Space. The minimum open space required for each development shall be as indicated in the sections for each type of subdivision in Chapter 20.60 JCC, Subdivision Types.
C. Qualifying Areas. The following features count toward the minimum open space requirements as described:
1. Conservation Areas. Any required preservation/conservation area shall count one hundred percent (100%) toward open space requirements.
2. Manmade Water Features. Any manmade water feature (including retention facilities) over one-quarter (1/4) acre in area shall count fifty percent (50%) toward the minimum open space requirements. However, it shall count one hundred percent (100%) toward minimum open space if it supports aquatic life and provides native habitat as follows:
a. Surface Area. A surface area at normal pool elevation of at least 32,670 square feet (¾ acre); and
b. Perimeter Access.
i. Width. A buffer area around the full circumference of the water feature of at least fifty (50) feet from the top of bank shall be available as open space.
ii. Plantings. This open space shall be planted and maintained as wildlife habitat. This includes use of native (no more than twenty percent (20%) lawn grass) species including prairie grasses and/or tree planting.
iii. Minimum Depth. The pool depth shall be at least fifteen (15) feet under at least ten percent (10%) of the overall pool area.
iv. A fountain or other means to mitigate algae growth shall be utilized.
3. Dry Detention Facilities. Manmade storm water detention facilities (dry) shall count seventy-five percent (75%) toward open space if they meet the following standards:
a. Area. The facility shall have at least 10,890 square feet of flat bottom (¼ acre).
b. Depth. The manmade depth of the detention facility shall not exceed four (4) feet from top of bank.
c. Slope. Manmade slopes within the detention facility shall not exceed a 4:1 ratio.
d. Perimeter Access.
i. Width. A buffer area around the full circumference of the facility of at least twenty-five (25) feet from the top of bank shall be available as open space.
ii. Plantings. This open space (facility and buffer area) shall be planted and maintained as usable area. This includes use of prairie grasses, native species, native ground cover, or lawn grass. Tree planting shall not be within the basin area or on the slopes of the bank.
4. Floodplain. The floodplain area of any natural stream, regulated drain, or natural river shall count toward the open space requirements.
5. Required Perimeter Landscaping. Fifty percent (50%) of the perimeter landscaping areas required in JCC 20.70.170 PL-01 – Perimeter landscaping standards, shall count towards the required open space.
6. Other. Other common areas set aside to meet open space requirements. [Ord. 12-27-11 § 7.15.]