2015 Innovation Award Winner
Joan Meitl with ACHD: Green Stormwater Infrastructure Implementation
The Local Highway Technical Assistance Council is pleased to announce our Innovation Idea Award Winner for the individual category, Joan Meitl. This employee has developed many alternative ideas for treating stormwater within the Ada County Highway District (ACHD) jurisdiction. This innovative idea includes tree cells, permeable paver alleys, and bioretention facilities.
Faced with new National Pollutant Discharge Elimination System (NPDES), Municipal Separate Storm Sewer System (MS4), permit requirements, and Boise River Total Maximum Daily Load (TMDL), ACHD has had to find alternative ways to properly control and treat stormwater.
ACHD hired Joan Meitl (Stormwater Quality Specialist) to lead ACHD in researching and implementing alternative stormwater management practices. Joan’s focus and approach has been on using Green Stormwater Infrastructure (GSI) instead of the more typical grey infrastructure approach. Joan has directed design and construction of three permeable paver alleys in downtown Boise. Two alleys were constructed in August 2014 and the third is currently under construction between 5th and 6th Streets, north of Idaho Street. Retrofitting 100 year old alleys has been a challenge, but Joan’s strong project management and communication skills have been key to the success of these projects. Along with the permeable alleys, Joan has been instrumental in getting partners such as City of Boise and CCDC to use tree cells in the ACHD right-of-way for stormwater control and treatment in addition to their original purpose of promoting a larger and healthier tree canopy (another stormwater benefit). Tree cells with the stormwater treatment component are currently being installed by CCDC in various downtown locations and are planned for construction by other private and public entities. Lastly, in May of 2014, Joan developed a demonstration bioretention swale using enhanced soils and native grasses and flowering plants near ACHD’s headquarters in Garden City. This demonstration project is being used to assess the soil mix and plants that can be used in the ACHD right-of-way with the goal of limited supplemental water and increased plant resiliency. To date the outcome of this project has been a complete success – the swale is attractive, very limited supplemental water has been needed during the long hot and dry summers, and it is doing its job of capturing stormwater runoff.
Joan has been a tireless advocate for cooperative partnerships along with educating agency staff, the development community and design professionals about the appropriate locations, use and maintenance of GSI in private and public spaces. Joan’s hard work is paying off and you can, and will, see it in the permeable paver alleys, stormwater tree cells, and bioretention swales/planters throughout the downtown Boise area. ACHD is also incorporating GSI in the design of future roadway projects throughout Ada County!
The use of GSI promotes a sustainable approach to stormwater management. The purpose of GSI is to mimic the natural water cycle of the landscape, reducing the negative impacts of stormwater runoff pollution on streams and rivers. GSI will minimize the impact of construction and development on natural hydrologic cycles and ecological systems. It will optimize water infiltration, create areas for local storage and treatment rather than concentrating flows and it distributes storage across the landscape, adjacent to areas of flow.
The two permeable paver alleys constructed to date are estimated to eliminate approximately 2.3 pounds of phosphorous and 121 pounds of sediment from entering the Boise River on an annual basis. Additionally, these alleys will no longer be creating drainage problems for adjacent property owners and thus ACHD Maintenance staff will need only to sweep the alleys one time per year versus performing maintenance after every large rain event.
The stormwater tree cells will eliminate a yet to be determined load of pollutants discharged to the Boise River from untreated stormwater runoff as well. The stormwater tree cells encourage large tree canopies which will intercept rainfall, with less runoff from adjacent impermeable surfaces. The larger tree canopies will also lessen the heat island effect created by the large buildings and impermeable surfaces found throughout the downtown Boise area.
The use of native plants in bioretention facilities provides green space, needs limited water, and provides stormwater quality treatment and runoff control.
Joan Mietl has focused her work on alternative stormwater management and ACHD is starting to really benefit.
To honor Joan as the 2015 Innovation Idea individual award winner, LHTAC presented her with an award, a free T2 class, and a cash prize of $250.
LHTAC will continue to showcase outstanding innovation submissions in our Tech News during the coming months.