5. What it is It is not
Urban stormwater retrofitting …a hydraulic or storm sewer
Identification of the highest analysis/planning tool
value stormwater BMP retrofit …primarily used for street-
practices by location (e.g., $/LB- scaping or park development
TP/YR) (secondary benefit)
A Water Quality planning tool …an elaborate excuse just to get
Supplement to existing analyses in more raingardens
One (major) consideration in
Capitol Improvement planning
A Precise and relative model
Labor investment and
quantity/quality of geospatial
and W.Q. data affects accuracy
6. Why an SRA?
Massive effort needed to affect
change in WQ
Disproportionate (insufficient)
funding resources
Disproportionate (insufficient)
labor resources
TMDL implementation guidance
Assurance of “bang-for-buck”
Challenges
Little-to-no outfall and source-
area field data
Limited time and budgets
25 SRA’s completed in 2.5 years by SWCD’s with
at least 5 more currently being worked on
7. The Plus Side
>30 years of pollutant
accumulation, behavior and
washoff data available
>20 years of BMP performance
data with more recent, state-of-
science research (bench and field)
Midwest city data (loading)
Several water quality models
based on this research
If outfall data exists, can be
calibrated to improve accuracy
Can easily be modified (build-
scenarios)
Repeatable (precise) 25 SRA’s completed in 2.5 years by SWCD’s with
at least 5 more currently being worked on
Multiple-year to-do-list based on
value (lbs/$/yr)
9. Scoping and Remote Data collection
Desktop Analysis
Field Reconnaissance
Treatment modeling and cost analysis
Report
10. Scoping
Water body needs
LGU needs
Existing data review (quality and needs)
Budgets and timeframes
Stakeholder consensus
Desktop Analysis
Field Reconnaissance
Treatment modeling and cost analysis
Report
11. Scoping and Remote Data collection
Desktop Analysis
Catchment and/or pipeshed delineation
Delineate and classify land uses
Delineate and classify permeable surface soils
Analyze existing WQ treatment / base load model
First-tier elimination of catchments for retrofitting
First-tier determination of WQ potential treatments
Field Reconnaissance
Treatment modeling and cost analysis
Report
12. Scoping and Remote Data collection
Desktop Analysis
Field Reconnaissance
Visit existing BMPs
Confirm/modify land-use and storm sewer data
Confirm/modify initial BMP-family selection
Selection of 1° and 2° BMP sites (parcels)
Site-specific data collection
Treatment modeling and cost analysis
Report
13. Scoping and Remote Data collection
Desktop Analysis
Field Reconnaissance
Treatment modeling and cost analysis
Development and optimization of BMP design
Iterations of “train” and/or level of treatment by
BMP quantity – load reduction estimates
Estimates of installation and life-cycle costs
Life-Cycle Cost analysis
Report
14. Scoping and Remote Data collection
Desktop Analysis
Field Reconnaissance
Treatment modeling and cost analysis
Report
Summary table – catchments ranked based on
performance ($/lb/LCyr)
Catchment profiles
Analysis methods and data
References
16. Existing
Stormwater
Ponds
Storage
Above
Public Land
Roadway
Culverts
STORMWATER
BMP
LOCATION Storage
Large
Parking Lots ANALYSIS Below
Outfalls
Within
Storage in
Conveyance
ROW
System
Describe the MCD partnership as a Joint Powers group serving 11 counties in the Metro area in 4 overall services
Our process uses on multi-agency partnerships
Our current focus is Urban subwatershed analysis with an agricultural component currently being developed
We apply analyses to three scales….1st decide which SW to work within (TMDL, Non-Degradation Plan, MS4 city requirements, existing WQ data, willing and able partner)2nd decide which catchments in the SW (described in following slides)3rd decide which sites within catchments (described…)After analysis completed, we can assist with selection of prime sites for optimized return on investment to assist in allocation cost share $Entire process ensures that the selection of individual BMP projects are in the optimal location, and have the optimal site-specific site design, to provide the best return on investment (best location, best project, best price)
There are 7 BMP locations we first screen each catchment for that are conducive to stormwater retrofits – each area has a set of specific bmps that are then considered
…these are the bmp families we considered
Map existing stormwater network and analyze performance – look for easy and inexpensive modifications to add or improve WQ treatment
Routing map
Screen each catchment for areas conducive to retrofits of various forms
Field reconnaissance investigation – considers site-specific limitations when selecting specific BMP’s
Identification of prime sites for bmp locations – provides a select list of addresses to visit when doing education and outreqach (canvasing for potential site installations) as opposed to random acts of conservation
Each prime catchment (those modeled for new treatment), is anlalyzed at three levels of treatment and reported on in a Catchmetnt Profile within the report
The top 10, or so, catchments, in terms of cost/benefit optimization, are presented in a summary table.