TO: Mayor Collins and Town Council Members
FROM: Kevin Burke, Town Manager
Brent Skoglund, Public Works Director
Jeremy Knapp, Engineering Services Analyst
DATE: April 13th, 2017
DEPARTMENT: Public Works and Engineering Department
Staff Contact Jeremy Knapp, 480-348-3622
End
AGENDA TITLE:
Title
Adoption of Ordinance 2017-01 updating the Town’s Storm Drainage Design Manual; and Adoption of Resolution 2017-06 establishing said document a public record
Body
Council Goals or Statutory Requirements:
Storm Water - Identify the scope, scale and possible solution to recurring storm water management issues.
RECOMMENDATION:
Recommendation
Adopt Ordinance 2017-01 updating the Town’s Storm Drainage Design Manual; and Adopt Resolution 2017-06 establishing said document a public record
Background
SUMMARY STATEMENT:
The Storm Drainage Design Manual is a document utilized by Town staff to review and approve improvement plans and storm water master plans on a day-to-day, lot-by-lot basis. It sets Town specific standards utilized by developers and builders to design and implement drainage improvements on private property. In addition, the Town uses it for guidance on stormwater improvements included in Town designed and constructed projects.
The Town’s current Storm Drain Design Manual was adopted in 1987 and has never been amended. One of Dibble Engineering’s (consulting engineer) tasks associated with the on-going watershed studies project was to update the manual. Town staff received a first draft of the updated manual in August of 2016. A staff stormwater committee, which consisted of representatives from the Building Department, Planning Department, Code Enforcement, Engineering, Public Works, and the Town Manager, reviewed the document and provided comments.
The revised document addresses many new regulations enacted since 1987 as well as some policy decisions. The new regulations include:
1. First flush requirements;
2. Storm water quality during and after construction;
3. Updated rainfall data and engineering practices;
4. Incorporation of all aspects of stormwater management (floodplain management, erosion hazards, etc.);
5. Introduction of low impact development; and,
6. Specific guidance on drainage reports, plans, easements, etc.
The revised manual was presented to Town Council at their February 9th, 2017 Work Study Session for comment and direction on adoption process. The discussion led to several Town Council questions which needed further input as well as council request for public comment.
The Engineering Department began publicizing the draft document, advertising a public meeting, and soliciting public comment the week of February 20th. Staff utilized the town’s website, e-mailed the notify me builders list, placed flyers at the Building and Engineering Departments counters, published a noticed in the March 8th Paradise Valley Independent, and placed ads on the TV screens at Town Hall. On March 21st, staff held a public meeting in the Community Room to present the draft and receive public input.
A summary of the public input was presented at the March 23rd Council Meeting. In addition, staff recommended to adopt the manual as presented which includes the following policy decisions:
1. Use the disturbed area only for flatland retention calculations
2. Hillside retention requirements on a tiered scale
3. Addition of first flush requirement for first ½” of rainfall
4. Retention basin easement requirements
Additionally, staff is recommending revising Section 15-2-12 of the Town Code which prohibits the discharge of pool/spa backwash into a sanitary sewer line. Approved pool backwash procedures are updated in the Storm Drain Design Manual which mimic those procedures of our neighboring jurisdictions, Phoenix and Scottsdale, both of which permit pool backwash into a sanitary sewer. Phoenix and Scottsdale are the town’s two sewer providers and have agreed that the town should update its policy to match theirs.
BUDGETARY IMPACT:
None
ATTACHMENT(S):
Ordinance 2017-01
Resolution 2017-06
Storm Drainage Design Manual 4/5/2017
Comment Tracking and Resolution
PowerPoint Presentation