Hydrologic regionalisation impacts on wet-weather control selection.

Area of Science:

• Environmental Engineering
• Hydrology
• Water Quality Management

Background:

• Wet-weather controls are crucial for managing stormwater runoff and improving water quality.
• Regional variations in rainfall patterns can significantly impact the performance of these controls.
• Understanding these regional differences is essential for effective stormwater management strategies.

Purpose of the Study:

• To evaluate regional differences in the United States regarding the hydrologic and water quality performance of wet-weather controls.
• To compare the effectiveness of flow-limited and storage-limited wet-weather control devices.
• To identify how rainfall patterns influence control performance across different U.S. regions.

Main Methods:

• Continuous simulation using the US Environmental Protection Agency (USEPA) Storm Water Management Model (SWMM).
• Characterization of controls as either flow-limited (e.g., screens, filters) or storage-limited (e.g., ponds, tanks).
• Analysis of performance metrics including percentage of annual runoff volume captured and percentage of total suspended solids captured.

Main Results:

• Regional differences in wet-weather control performance were observed across the United States.
• Performance varied based on control type (flow-limited vs. storage-limited) and design parameters (inflow capacity, storage volume, drawdown time).
• Rainfall patterns were identified as the primary driver of these regional performance variations.

Conclusions:

• The effectiveness of wet-weather controls is significantly influenced by regional rainfall characteristics.
• Tailoring control selection and design to local rainfall patterns is critical for optimizing stormwater management.
• SWMM simulations provide valuable insights into regional performance disparities for informed decision-making.