Item 3Storm Water Management
A presentation to
City Council
Planning & Zoning Commission
by the
Quality Development Focus Area Cabinet
January 27, 2009
City of Southlake Strategy Map
Live Our Core Values
The City of Southlake provides municipal services that support the highest quality of life for our residents and businesses. We do this by delivering outstanding value and unrivaled
quality in everything that we do.
Fulfill Our
Mission
Promote
Learning
and Growth
Provide
Financial
Stewardship
Serve Our
Customers
B5 Optimize use of technology
B4 Provide high quality customer service
Manage the
Business
Safety Mobility Infrastructure Performance Management Quality Partnerships
and Security and Service Delivery Development and Volunteerism
Deliver on Our
Focus Areas
Integrity ● Innovation ● Accountability ● Commitment to Excellence ● Teamwork
Presentation
Review fundamentals
Overview regulatory environment
Identify roles and responsibilities
Outline strategy and funding
Discuss public policy issues
Answer legal questions
Fundamentals
Fundamentals: FAQs
National Flood Insurance Program
Frequently Asked Questions
Fundamentals: Key Terms
Glossary of Terms
Examples:
Hydrology
Hydraulics
Impervious Coverage
Storm Water Runoff
Fundamentals: Key Terms
100 yr Storm – a storm that has 1 in 100 or 1% chance of occurrence in any year
10 yr Storm - a storm that has 1 in 10 or 10% chance of occurrence in any year
2 yr Storm - a storm that has 1/2 or 50% chance of occurrence in any year
Flood Plain Graphic
Fundamentals: Detention vs. Retention
Designed for 100 year storm
Retention – Permanently restrains flow of water. Generally provided for aesthetic purposes
Detention – Temporarily restrains flow of water to reduce downstream impact
Staged Discharge
Retention Pond (with detention)
Detention portion of pond
Retention Component
HOA Responsibility
City Responsibility
Public Drainage Easement (City Responsibility)
Private Amenity – Retention Pond (HOA)
Direction of
Flow
Outfall Structure (High Flow)
Detention Component (City)
Retention Component (HOA)
Outfall Structure (Low Flow)
Retention component
(HOA/POA Responsibility)
Developer Agreement (Amenity)
Detention component
(City Responsibility)
Outfall Structure
Bear Creek
Fundamentals: Major Basins
Regulatory Environment
Regulatory Environment
National Flood Insurance Program (NFIP)
Administered by FEMA
Southlake – NFIP participant since Feb 1974
Floodplain development/enforcement
Administered by FEMA (USACOE possible involvement)
City of Southlake – Enforcement Authority
Environmental Quality of Creeks/Streams
EPA
TCEQ
City of Southlake (Phase II municipality)
Regulatory Environment
Texas Water Law
Cannot divert or block natural flow of water
Cannot adversely impact other property owners
Regulatory Environment
City Ordinances
Drainage Ordinances (217, 461 and 605)
Storm Water Utility (900 and 901)
Critical Drainage Structure Report
Storm Water Management Plan
Erosion Control Ordinance for Construction
Illicit Discharge Ordinance (Future)
Post Construction BMP Ordinance (Future)
Roles & Responsibilities
Roles & Responsibilities
Roles & Responsibilities: Staff
Draft/recommend proposed policy
NFIP/Floodplain administrator/ Enforcement
Review developments for compliance
Administer Storm Water Management Plan
Master Drainage Plan
CIP Implementation
Education outreach/ Information source
Storm water system maintenance
Roles & Responsibilities: Elected/Appointed Officials
Consider/adoption/establishment of
City drainage policy/ ordinances
Master Drainage Plan
Ensure proposed land development is consistent with Master Plans, ordinances and regulations
City Council adopts budget for CIP drainage related projects
Adopt storm water utility operating budget
Roles & Responsibilities: Property Owner
Per Section 9.02, Ordinance 605:
Maintain all creeks/natural drainage ways and all unimproved drainage easements on private property
Maintain borrow ditches and culverts
Periodic removal of underbrush, trash and debris, mowing and general upkeep of borrow ditch to maintain positive flow of storm water within ditch and culvert
Storm Water Management In Southlake
Strategies & Funding
402 Localized $ 26,482,772
17 Secondary $ 5,753,810
20 Primary $ 19,679,074
$ 51,915,656*
Storm Water Management and Funding
* 2006 estimate
Storm Water Management and Funding
Storm Water Utility District
Adopted October 2006
Residential Parcels:
$8/month fee
Non-Residential Parcels:
Fee = Allocated Portion of Parcel in square feet (SF) times residential monthly rate/s.f.
Storm Water Management and Funding
Cost-of-Service
Operations and Maintenance
Flood Control
Water Quality
Broad Use of Funds
Existing Stormwater Problems
Future Improvements
Bond Capacity
Drainage Projects Funded
13.4%
Additional Drainage Projects Remaining
86.6%
Storm Water Management and Funding
Storm Water Management and Funding
Storm Water Utility District Collections
*To Date
$2,626,095
Storm Water Management and Funding
Capital Projects
Dove Drainage - $2.5 million
2300 L.F. of 8’ x 5’ Box culvert – 100 yr storm
Debt service - $225,000/year
Operational Items
Borrow Ditch cleaning:10,000 LF
Culvert Installations: 1500 LF (various sizes).
Culverts cleaned and jetted: 3000 LF
Cubic yards sediment and debris removed: 15,000 CY
Operational Issues (Cont’d)
Sod and hydro-mulch installed/cast: 11,000 SY
Rip rap material used for erosion in drainage channels/Creeks: 800 TON
Silt fence installed: 3000 LF
Catch basins installed: 5 units.
Exposed aggregate concrete flumes installed: 8,500 SF
Concrete channels cleaned: 3,000 LF
Public Policy Issues
Public Policy Issues
Public Versus Private Water
An Issue of Responsibility
Funding Challenges
Project Prioritization
Storm Water Utility District
Supplemental Funding Sources
Community Rating System
Legal Framework
Discussion