Number
081664
Version
SUBSTITUTE 2
Reference
Sponsor
ALD. KOVAC, COGGS AND HAMILTON
Title
A substitute ordinance relating to storm water management regulations applicable to properties within the Milwaukee River greenway site plan review overlay zone.
Sections
120-7-1.5 cr
120-14 cr
Analysis
This ordinance creates storm water management regulations that apply only to properties within the Milwaukee River greenway site plan review overlay zone, a zoning district located along the Milwaukee River between the former North Avenue Dam and the city limits at Silver Spring Drive. These provisions are intended to supplement the city’s existing storm water management regulations. When an overlay zone storm water management provision is in conflict with any other provision of the city’s storm water management regulations, any other provision of the city code, or any applicable state or federal law, the more restrictive provision shall apply.
The new storm water management regulations include:
1. A storm water management plan shall be required if a development or redevelopment causes a land disturbing activity of one-half acre or more, causes the cumulative area of all land disturbing activities at a property to be one-half acre or more over a 3-year period or causes an increase of 0.5 acres or more of impervious area.
2. If the development or redevelopment causes an increase of 0.5 acres or more of impervious area, the release rate and requirements shall be governed by Milwaukee metropolitan sewerage district chapter 13 - surface water and storm water rules.
3. Any development or redevelopment shall, by design, reduce to the maximum extent practicable the total suspended solids load by 80%, based on an average annual rainfall, as compared to no runoff management controls. This requirement applies whenever a storm water management plan is required in the separate storm sewer system or if storm water runoff from the development or redevelopment meets any of the criteria in item 1 and storm water runoff from that development or redevelopment discharges into waters of the state.
Body
The Mayor and Common Council of the City of Milwaukee do ordain as follows:
Part 1. Section 120-7-1.5 of the code is created to read:
120-7. Control of Storm Water Discharge.
1.5. MILWAUKEE RIVER GREENWAY SITE PLAN REVIEW OVERLAY ZONE. This section shall not apply to any property located within the Milwaukee River greenway site plan review overlay zone, as shown on the city zoning map and established by common council file number 081568. Properties in the overlay zone shall be subject to the storm water management regulations of s. 120-14.
Part 2. Section 120-14 of the code is created to read:
120-14. Control of Storm Water Discharge for the Milwaukee River Greenway Site Plan Review Overlay Zone. 1. PURPOSE. The common council finds that the Milwaukee River corridor between the former North Avenue dam and the city limits at Silver Spring Drive contains native vegetation, wildlife habitat, natural bluffs, stream banks and waterways, and other valuable natural resources in need of protection. The regulations of this section are established to provide this protection by reducing the quantity of polluted storm water runoff, encouraging the planting of native vegetation, stabilizing stream banks and bluffs, mitigating flooding of the Milwaukee River and its tributaries, and reducing flows to the city’s combined sewer system.
2. APPLICABILITY. This section applies only to all properties within the Milwaukee River greenway site plan review overlay zone, as shown on the city zoning map and established by common council file number 081568.
3. CONFLICTING REQUIREMENTS. The provisions of this section are intended to supplement, not replace, other provisions of this chapter. If any provision of this section conflicts with any other provision of this chapter, any other section of this code, or any applicable state or federal law, the more restrictive provision shall apply.
4. DEVELOPMENT CRITERIA. A storm water management plan is required if any of the following criteria are met:
a. The development or redevelopment causes a land disturbing activity of one-half acre or more.
b. The development or redevelopment causes the cumulative area of all land disturbing activities at a property to be one-half acre or more over a 3-year period.
c. The development or redevelopment occurring causes an increase of 0.5 acres or more of impervious area.
5. RUNOFF RELEASE RATE. a. If the development or redevelopment occurring causes an increase of 0.5 acres or more of impervious area, the release rate and requirements shall be governed by Milwaukee metropolitan sewerage district ch. 13 - surface water and storm water rules.
b. If the development or redevelopment occurring meets any of the criteria in sub. 4 and does not cause a land disturbing activity of 0.5 acres or more of impervious area, the peak runoff flow rates under post-development conditions shall be at least 50% less than the peak runoff rates under pre-development conditions.
6. RUNOFF DISCHARGE QUALITY CONTROL. a. Any development or redevelopment shall, by design, reduce to the maximum extent practicable the total suspended solids load by 80%, based on an average annual rainfall, as compared to no runoff management controls. No person shall be required to exceed an 80% total suspended solids reduction to meet the requirement of this paragraph.
b. This subsection applies whenever a storm water management plan is required in the separate storm sewer system or if storm water runoff from the development or redevelopment meets any of the criteria of sub. 4 and storm water runoff from that development or redevelopment discharges into waters of the state.
7. ADDITIONAL REGULATIONS. The following additional storm water management regulations shall apply to development or redevelopment within the Milwaukee River greenway site plan review overlay zone:
a. Storm water best management plans shall show topographical lines and bluff lines.
b. Storm water best management practices shall be located as close to the source of runoff as possible, and shall emphasize techniques that incorporate native plants, shrubs and trees and mimic natural landscape features.
c. Storm water management facilities shall not be permitted within the primary environmental corridor, as mapped by the southeastern Wisconsin regional planning commission, unless the city engineer determines, based on evidence provided by the developer, that such facilities are necessary to protect public safety or bluff stability. The placement of storm water management facilities within the 50-foot setback from top of bluff required by the overlay zone’s design standards, as adopted by the common council in file number 081569, shall be permitted if these facilities emphasize the use of such storm water management practices as rain gardens, vegetated swales and similar techniques, and do not adversely impact bluff stability and public access.
d. Every storm water management facility shall be designed and constructed in a manner to minimize erosion and bluff instability. The permit requirements of ch. 30, Wis. Stats., shall also apply to any alterations to the river bank.
e. A storm water management plan required pursuant to this section shall be prepared in accordance with the manual of storm water management practices, including both the provisions that apply citywide and the provisions that apply only to the Milwaukee River greenway site plan review overlay zone.
LRB
APPROVED AS TO FORM
__________________________
Legislative Reference Bureau
Date:______________________
Attorney
IT IS OUR OPINION THAT THE ORDINANCE
IS LEGAL AND ENFORCEABLE
__________________________
Office of the City Attorney
Date:______________________
Requestor
Drafter
LRB09142-4
JDO
05/11/2010