PARENT SESSION
Poster Session # 22: Late-Breaking Newsworthy Posters

Friday, August 8 Presentation from 8:30 AM to 10:00 AM. SITCC Exhibit Hall B.

Urban Spartina.

Smith, Ken^*,1, Felson, Alexander^*,1, ¹ Ken Smith Landscape Architect, New York, New York, USA

ABSTRACT- This poster will describe a new small-scale experimental salt-water marsh to be designed for Manhattan's East River. The project is quite unusual, and provides an opportunity to study and re-calibrate an urban wetland marsh. The functional marsh includes saltwater grasses (Spartina alterniflora) growing in wood planter boxes set on a typical I-beam pier and elevated above the East River at 34th Street. They are raised above mean high tide to remove them from damaging river conditions. Ideally, Spartina would occur within the tidal zone, but today the River is inhospitable to vegetative growth. The poster describes many aspects of the project including: the types of salt-water plants to be planted, plant spacing, soil mixes and the use of hydrogel (a plastic water retaining formed gel pellets). Irrigation diagrams on the poster will illustrate and explain the use of pumped East River salt water and fresh water. Irrigation is the key to the project. Boxes are flooded twice daily to mimic tidal flooding patterns, and because marsh grasses actually grow better in freshwater, city water is used for daily irrigation. Weekly saltwater flooding is used, not for irrigation, but more as an herbicide (deterring invading plant species). Salt water's multiple functions in this project (including for irrigation, as an herbicide, to introduce larvae including blue crab and mussels and to provide nutrients and minerals to the wetland environment) are explained. Construction drawings illustrating depths and general dimensions including the sizing and layout of the pump (exposed on site as an educational display) as well illustrating the flow of salt water along exposed stainless steel channels running underneath a paneled walkway over part of the River. The salt water is activated by an on-site pump which is itself powered by either land or water turbines (to be determined). Taken together, the poster will indicate the irrigation system's flexibility (considering both salt and fresh water) and the opportunity to experiment and quantify the changing dynamics overtime.

Key words: Urban, Salt Water Marsh, Design, Spartina alterinflora