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Project ID: 2004PA27B

Title: Split-Flow Stormwater Demonstration and Feasibility Study

Project Type: Research

Focus Categories: Hydrology, Water Quantity, Water Quality

Keywords: Stormwater, Watershed, Mitigation, Split-Flow, Hydrology

Start Date: 03/01/2004

End Date: 02/28/2006

Federal Funds: $15,000

Non-Federal Matching Funds: $30,000

Congressional District: 5th of PA

Principal Investigator:
Stuart Patton Echols


Engineers, Planners, Water Resource Professionals, Local Government Officials and Land Development Professionals are expected to plan and regulate urban developments that protect and restore our natural ecosystems. However, every time we create a new impervious building, plaza, sidewalk or parking space, we increase runoff and degrade our aquatic environments. As a result of new federal regulations, thousands of municipal governments are now required to develop, adopt and implement stormwater management strategies to reduce non-point source pollution directly related to new development. Despite these regulations, current stormwater management strategies have shown only limited success in protecting aquatic environments that depend on the preservation of existing natural processes. To address this issue, we need a new stormwater management strategy that regards runoff as a valuable resource, emulates the natural hydrology system, fulfills our environmental goals, and satisfies local flood control regulations. The Split-Flow Stormwater Management Strategy is a newly developed method for managing stormwater on-site by replicating the natural processes of evapo-transpiration, soil infiltration and stream flow. This Split Flow strategy has been modeled and studied by comparing its design feasibility and construction cost to other methods with promising results. However, development of the strategy is at a standstill due to a lack of in-ground testing. The purpose of this proposal is to implement initial in-ground testing of the strategy. The knowledge gained from the proposed in-ground testing will offer practical evidence of the strategy’s usefulness and reveal areas in need of further refinement.

The study will be the first in-ground test to assess the Split-Flow Stormwater Design Strategy’s ability to replicate natural discharge flow rates, volumes, frequency and duration by comparing runoff discharges from parking lots equipped with Split-Flow systems to runoff discharges from undeveloped adjacent analogous land. The primary objective of this study is to test the Split-Flow Stormwater Management Strategy’s efficacy in preserving the land’s natural stormwater discharge rates, volume, frequency and duration. Another outcome of the study will be the creation of a sustainable stormwater management demonstration and education facility within the Spring Creek Watershed, located in Centre Country, PA. The longer-range goal of this study is to continue development of the Split-Flow Stormwater Management Strategy in order to provide an ecologically responsible stormwater management alternative based on preserving the land’s pre-development hydrological processes. Funding provided by the PA Water Resources Research Center will be used to procure monitoring equipment for the Split-Flow demonstration including: stormwater flow, rainfall, soil moisture, water & air temperature, water depth meters and on-site data recording equipment.

The Split-Flow needs to be tested before it can be applied to land development practice where it should help resolve many of the problems that current stormwater management methods need to address. As a result of Split-Flow strategy, the actual difference in volume created by development can be distributed throughout a site to restore groundwater recharge; natural runoff that existed before development can be cleaned and routed downstream; and the first flush containing the highest levels of pollution can be diverted and isolated in effective treatment facilities. Under such conditions, the reduction in downstream degradation should be quite substantial.

Progress/Completion Report PDF

U.S. Department of the Interior, U.S. Geological Survey
Maintained by: John Schefter
Last Updated: Wednesday July 13, 2005 4:52 PM
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