Title
Amending Chapter 63 and Chapter 69 of the Legislative Code pertaining to Stormwater Run-Off and Wetlands.
Body
An ordinance amending various section of the Legislative Code pertaining to zoning regulations: (1) amending storm water run-off from off-street parking facilities [Leg. Code § 63.319(a)]; (2) delegating review and approval authority for wetland replacement applications to the zoning administrator [Leg. Code §§ 63.604-.605 and 63.607]; and, (3) harmonizing general standards for storm water run-off rates to be consistent with run-off rates regulated under Leg. Code Chap. 52. [Leg. Code § 69.504(g)(1)].
SECTION 1.
Statement of Legislative Findings and Intent of the City Council: Upon the recommendation of the City’s water resources coordinator, the department of public works and the planning commission, for the purpose of ensuring the City continues to efficiently manage stormwater runoff in a manner consistent with applicable federal and state stormwater management requirements, the Saint Paul Local Surface Water Management Plan, the standards and best management practices of the Saint Paul Stormwater Management Design manual, and upon the report and recommendation of the planning commission set forth in planning commission resolution No.17-34, amendments to the following sections of the Legislative Code, contained in and more commonly referenced as the “zoning code,” are hereby made.
NOW, THEREFORE, THE COUNCIL OF THE CITY OF SAINT PAUL DOES ORDAIN:
SECTION 2.
That Legislative Code §§ 63.319(a), pertaining to stormwater runoff from off-street parking facilities, is hereby amended to read as follows:
Sec. 63.319. Stormwater runoff.
(a) For off street parking facilities with greater than one-quarter (¼) of an acre of total disturbed area, the following provisions for stormwater management shall apply:
(1) Stormwater drainage into public sewers shall be controlled so that peak stormwater discharge rates from the site for all storms up to and including the critical 100-year frequency will not exceed:
Q = 1.64 x A
where Q = the maximum acceptable discharge rate in cubic feet per second and A = the site area in acres.
Parking facilities shall be designed in accordance with best management practices to comply with required local and regional water quality, volume, and rate control standards. These standards include but are not limited to chapter 52, stormwater runoff. Parking lots shall also abide by operation and maintenance regulation as specified by local and regional authorities.
(2) Stormwater landscaping shall be designed to include an under drain system if stormwater landscaping is located in areas with hydrologic soil type C (Sandy clay loam).
(3) Stormwater landscaping shall not be required if located in areas with hydrologic soil type D (Clay); groundwater or bedrock within three (3) feet of the bottom of the infiltration area; nearby wells or utilities; or potential contamination.
(b) For parking facilities with greater than one (1) acre of total disturbed area, other local, state, and regional regulations also apply.
SECTION 3.
That Legislative Code §§ 63.604, 63.605, and 63.607, pertaining to wetland conservation and the review and approval of wetland replacement applications, is hereby amended to read as follows:
Sec. 63.604. Exemption and no-loss determinations.
The zoning administrator shall make determinations whether plans to drain or fill wetlands are exempt from the requirements to replace drained or filled wetlands, as set forth in Minn. Rules Part 8420.0210 8420.0420, and whether proposed work will result in a loss of wetlands, as set forth in Minn. Rules Part 8420.0220 8420.0415. The zoning administrator may seek the advice of the technical evaluation panel on questions of wetlands delineation and type.
The zoning administrator's decisions are final unless an administrative appeal to the board of zoning appeals is filed as set forth in section 61.700 of the zoning code.
Sec. 63.605. Sequencing.
The zoning administrator planning commission may not consider a wetland replacement plan unless it finds that the applicant has complied with all of the principals of sequencing in Minn. Rules Parts 8420.0520. Provided that if the size of the wetland to be drained or filled is less than one-tenth (0.1) of an acre, the zoning administrator shall make the sequencing findings as set forth in Minn. Rules Part 8420.0520, Subpart 2.
Sec. 63.607. Replacement plans.
(a) No draining or filling of wetlands shall take place until plans to replace the drained or filled wetlands have been approved by the zoning administrator planning commission. Replacement plans shall conform to all the requirements of Minn. Rules Parts 8420.0530--.0550.
(b) Plans to drain or fill wetlands and to replace the drained or filled wetlands shall be acted on by the planning commission in accordance with section 61.500, Conditional use permits, of the zoning code and with the additional notice and time requirements of Minn. Rules Part 8420.0230.
SECTION 4
That Legislative Code § 69.504(g), pertaining to design standards for stormwater drainage, is hereby amended to read as follows:
Sec. 69.504. - Drainage and storm sewers.
(g) Stormwater detention ponds.
(1) Drainage Criteria: The subdivider shall provide for stormwater detention in compliance with the following standards:
a. Drainage from any site being developed or extensively redeveloped with drainage to the public sewer or public right-of-way shall be controlled so that peak stormwater discharge rates from the site for all storms up to and including the critical one hundred-year storm will not exceed:
Q = 1.64 × A
where Q = the maximum acceptable stormwater discharge rate in cubic feet per second, and A = the site area in acres. in accordance with best management practices to comply with required local and regional water quality, volume, and rate control standards. These standards include but are not limited to chapter 52, stormwater runoff.
b. Where feasible, the drainage system shall be designed so that all stormwater runoff and surface water from the site shall discharge in a manner so as to preclude drainage of water onto the adjacent properties.
c. Summary of 100-years storm for St. Paul. The following table is a summary of the total rainfall depth for various duration 100-year storms in St. Paul. The information has been taken from Five- to Sixty-Minute Precipitation Frequency for the Eastern and Central United States and Technical Paper No. 40-Rainfall Frequency Atlas of the United States. Both of these publications were prepared by the National Weather Service.
The term "100-year storm" as used in this summary, refers to a storm of a given duration and rainfall depth which has a one percent probability of occurring during any given year in a particular locale.
|
Duration-Minutes |
Rainfall Depth-Inches |
|
5 |
0.84 |
|
10 |
1.38 |
|
15 |
1.76 |
|
30 |
2.44 |
|
60 |
3.15 |
|
120 |
3.50 |
|
180 |
3.80 |
|
360 |
4.40 |
|
720 |
5.20 |
|
1,440 |
5.90 |
SECTION 4.
These amendments shall take effect and be in force thirty (30) days following passage, approval, and publication.