Manmade Lake Design for Maximizing Stormwater Quality Treatment and Reuse
Purpose: Illustrate how engineered lake systems can be applied with innovative design elements that provide exceptional water quality treatment while functioning as principal stormwater management infrastructure facilities in urban watersheds. Main Ideas: Manmade lake facilities have traditionally been considered ornamental and landscape features primarily serving aesthetic purposes in golf courses and parks. However, a new procedure is presented illustrating how engineered lake systems can be applied with innovative design elements that provide exceptional water quality treatment while functioning as principal stormwater management infrastructure facilities in urban watersheds. These systems can replace conventional urban stormwater conveyance and treatment facilities while adding value to the community. Application of these specially developed manmade lake systems has resulted in effective treatment of stormwater and generated exceptional water quality far beyond conventional BMP methods typically applied. Currently, stormwater pollution is commonly addressed in urban watersheds through the introduction of a limited number of standard structural control measures or BMPs. These methods generally have limited pollutant removal effectiveness, perform single functions, require considerable land, have maintenance challenges, high construction costs, do not provide opportunities for water reuse, and are typically unsightly while having limited aesthetic appeal to the community. Planned manmade lakes, particularly in semi-arid areas, offer a combination of many unique advantages for stormwater management as well as other benefits that are not available in conventional stormwater systems, including: (1) continuous year-round natural treatment process, (2) stormwater conveyance and storage, (3) exceptional water quality, (4) flood protection, (5) combined landuse elements, (6) significantly reduced infrastructure costs, (7) dry weather flow treatment, (8) landscape and aesthetic treatment through a naturalized water system, (9) increased surrounding land values, (10) natural ecosystem benefits, (11) recreational feature, and (11) aesthetic urban design element for communities. Summary of the Tools, Ideas and Concepts: A unique engineered design for man-made lake systems has been developed specifically for stormwater management that involves utilizing key design features including (1) lake biofilters, (2) lake aeration, and (3) water quality filters and wetland planters. Operation and maintenance requirements associated with these advanced treatment elements for manmade lake systems is presented with specific requirements and typical costs. Multiple case studies of manmade lakes designed specifically for stormwater management and reuse will be presented including a case study of a 70-acre residential development including water quality monitoring data. A comprehensive design procedure is provided that reviews the various design issues, criteria, requirements, and techniques used in developing man-made lake features for stormwater treatment and reuse purposes. Interactive Experience: 1) demonstration of how a design process is applied to an actual case study, 2) presentation of actual in-field photos, 3) high level custom graphics to illustrate key design features, 4) drone video of case study in operation, 5) providing attendees a magazine-style handout illustrating key presentation take-aways. Conference Theme: Creative application of stormwater treatment and recycling within a multi-purpose facility.