The Design and Use of Detention Facilities for Stormwater Management
Detention ponds are probably the most common management practice for the control of stormwater. If properly designed, constructed, and maintained, they can be very effective in controlling a wide range of pollutants and peak runoff flow rates. There is probably more information concerning the design and performance of detention ponds in the literature than for any other stormwater control device. Wet detention ponds are also a very robust method for reducing stormwater pollutants. They typically show significant pollutant reductions as long as a few design-related attributes are met. Many details are available to enhance performance, and safety, that should be followed. Many processes are responsible for the pollutant removals observed in wet detention ponds. Physical sedimentation is the most significant removal mechanism. However, biological and chemical processes can also contribute important pollutant reductions. The extensive use of aquatic plants, in a controlled manner, can provide additional pollutant removals. Wet detention ponds also are suitable for enhancement with chemical and advanced physical processes.
This course will use the DETPOND stormwater detention pond model (model and documentation) to evaluate and design stormwater detention ponds for a wide range of conditions. DETPOND is based on the same modeling approach used in SLAMM, but provides more detail to enable more effective evaluations. This course also includes extensive documentation of successful pond designs and approaches.
This material is excerpted from: Pitt, R. Stormwater Quality Management, Part Two: Treatment of Stormwater. CRC/Lewis. Boca Raton, FL. Publication forthcoming.
The following is an abbreviated table of contents of the course material available from the downloadable pdf file:
Introduction
Expected Detention Pond Performance
Potential Detention Pond Problems
Wet Detention Pond Design Guidelines to Minimize Potential Problems
Required Stormwater Detention Pond Maintenance
Basic Wet Detention Pond Design Guidelines
Wet Detention Pond Costs
Pond Size Calculation
Background
Multiple Benefits of Detention Facilities
Dry Ponds
Wet Detention Ponds
Extended Detention (Combination) Ponds
Roof Storage
Up-Sized Pipes
Underground Rock-Filled Detention
Use with Other Controls
Examples of Detention Pond Performance
Oil/Water Separators
Problems With Wet Detention Ponds
Safety of Wet Detention Ponds
Nuisance Conditions in Wet Detention Ponds and Degraded Water Quality
Attitudes of Nearby Residents and Property Values
Maintenance Requirements of Wet Detention Ponds
Routine Maintenance Requirements
Sediment Removal from Wet Detention Ponds
Vegetation Removal from Wet Detention Ponds
Detention Pond Costs
Guidelines To Enhance Pond Performance
Insect Control and Fish Stocking
Aquatic Plants for Detention Ponds
Locating Ponds
Pond Surface Area and Shape
Pond Water Depth
Pond Side Slopes
Internal Baffles
Outlet Structures
Emergency Spillways
Multiple Detention Ponds and their use With Other Control Devices
Enhancing Pond Performance During Severe Winter Conditions
Detention Pond Design Fundamentals
Upflow Velocity
Effects of Short-Circuiting on Particulate Removals in Wet Detention Ponds
Residence Time and Extended Detention Ponds
Particle Size
Particle Settling Velocities
Pond Water Losses and Liners
Flow Rate Reductions In Water Quality Ponds
Control of Pollutants Other Than Suspended Solids
Natural Bacterial Dieoff in Detention Ponds
Design Based on NURP Detention Pond Monitoring Results
Importance of Reservoir Routing
Introduction To Storage-Indication Method
Outflow Rates From Discharge Control Devices
Stage-Area and Storage-Indication Curve Development
Storage-Indication Calculation Procedure
Selecting Outflow Control Devices To Meet Water Quality Objectives
Wet Pond Design Criteria for Water Quality
The Use of the DETPOND Program to Statistically Evaluate Wet Pond Performance
DETPOND Verification using Data Collected at the Monroe St. Detention Pond, Madison, WI
Method of Investigation
Data Analysis and Observations
Particle Size Distributions and Short-Circuiting
Monroe St. Pond Verification Conclusions
Verification Based on Measured Performance at a Landfill Pond in Birmingham, AL.
Issues Associated with Using a Continuous Record of Rains vs. a Single Event Storm
Stream Habitat Benefits Associated with Peak Flow Reduction Criteria
Untreated Flows Associated with Single-Event Criteria
Benefits of Using Continuous, Long-Term Simulations
Example Use of DETPOND and Wet Detention Pond Analyses
Analysis of the Wet Stormwater Detention Pond for the Brook Highland Shopping Center
The Use of DETPOND to Evaluate Wet Detention Pond for Minneapolis-St. Paul Airport
Design Suggestions for In-Receiving Water Detention
Retro-fit Examples for Providing Water Quality Benefits in Existing Dry Detention Ponds
Evaluation and Recommended Modifications to a Small Dry Stormwater Detention Pond
Retrofit of Dry Detention Pond in Sunnyvale, CA
Retrofit Case Examples from the Center for Watershed Protection (Claytor 1998)
Conclusions
References
Appendix A: User Guide for DETPOND
Example Design Calculations and Evaluation Using DETPOND
Steps in Entering Data for Evaluation in DETPOND
Example 1: Create a Rain File for Use in DETPOND
Example 2: Edit the Rain File Created in Example 1
Example 3: Create a Rain File from CD ROM Data
Example 4: Stochastically Generate a Rain File
Example 5: Create a Particle Size Distribution File