Natural Streams Entering Combined Sewer Systems Geoffrey Lenat Design Research Fall 2014 Abstract I am interested in locating natural streams that have been diverted into combined sewer systems. I want to research methods of reducing the amount of water entering the combined sewer system, especially in instances where streams are contributing to sewer flow during dry weather. I will begin my research by looking at historic maps showing natural stream routes that now enter combined sewer areas. I will look for points where surface streams still exist, the size of their watershed, and their entry point into the sewer system. I am hoping to discover situations where storm water entering the combined sewer system from a large watershed can be diverted and separated from the combined sewer system. This type of storm water diversion could significantly reduce combined sewer overflow. Viele, “Topographical Atlas of the City of New York, Including the Annexed Territory Showing Original Water Courses and Made Land.” 1874. Natural Streams Entering Combined Sewer Systems Geoffrey Lenat Design Research Fall 2014 Tibbetts Brook Bronx, NY Most of the natural hydrology in This map from 1917 shows the this area has been erased. This extensive web of new street map shows the southwest Bronx construction happening in the in 1872. Tibbetts Brook is flowing area, and how it relates to southwest, across Braodway, into the historic stream bed. Also, the Spuyten Duyvel Creek, which Spuyten Duyvel Creek, is gradually forms the north end of Manhattan becoming the Harlem River Ship Island. Canal. The original route of the Spuyten Duyvel is still visible in this map. ed quibusapis di sus quasped estibusae “Petersen’s New Map of the Bronx, nonsequi omnis seditas estectur? Showing All Present and Proposed Trolley Asperibusam sit et, nones de consequis ut and Rapid Transit Lines.” 1917. volupta delitiostrum Natural Streams Entering Combined Sewer Systems Geoffrey Lenat Design Research Fall 2014 Current Scenario Where did Tibbetts Brook Go? In this current map, Tibbetts This map shows the southwest Brook has disapeared south of Van corner of Van Cortland Park. Van Cortlandt Lake. The original route Cortlandt Lake, which is part of the Spuyten Duyvel Creek has of Tibbetts Brook, spills into a also disapeared. It has become sewer pipe. The pipe curves to the Harlem River, which is not the northwest, and then to the actually a river at all, but a canal southwest, where it joins up with a between the Hudson River and large sewer under Broadway. This Long Island Sound. Broadway sewer is part of New York’s combined sewer system. In dry weather, everything flowing in the sewer is now diverted to the Wards Island Wastewater Treatment Plant. In wet weather, much of the sewage flows directly into the Harlem River. Open Street Map. “Topographic Survey - Van Cortlandt Park.” New York City Department of Parks and Recreation. 1982 Geoffrey Lenat Design Research Fall 2014 NATURAL STREAMS ENTERING POSSIBLE CONTROL POINTS NATURAL STREAMS ENTERING COMBINED SEWER SYSTEMS COMBINED SEWER SYSTEMS Storm Water Inlets Storm Water Inlets (Only flowing during (Only flowing during wet weather) Blue Roofs wet weather) (Separated Sewer System) FRAMEWORK: Cisterns How much water What is the percentage Retention enters the natural of impervious land in CONTROL POINT Where are the CONTROL POINT Bioswales stream via separated the watershed? Househould Prevent stormwater from entering Impervious surfaces sewers? sewer system: Sanitary Sewage Aquifer draining to sewer system Green Roofs - retention CONTROL POINTS? Absorbtion Seepage - absorbtion “Natural” Dry Wells Stormwater Commercial/ How much water Industrial waste could be retained? Alter existing lakes to This schematic breaks down retain stormwater and slowly release Will this be damaging the components of the over time to lake ecosystem? CONTROL POINT Enhance wetland Large scale retention: Tibbetts Brook/Broadway CONTROL POINT Large scale Alter existing lakes environments to - alter existing lakes and wetland systems to Natural stream bed retention and wetland promote transpiration Natural Stream containing water from systems Will this put a dent in retain water during precipitation events and Sewer system. downstream flow? slowly release over time natural sources and separated sewer system Older Street Aligned Combined Sewer Pipe Is a route CONTROL POINT It also shows possible CONTROL POINT available? Not Pipe to original Re-route stream water directly to river: under Street? - underground pipe Control Points in this sytem. The point at which the downstream river - engineered “natural” stream bed natural stream is diverted Re-route stream Underground pipe - combination of both into a pipe water directly to Pipe to river in Drilling, pumping river alternate watershed required? Engineered “natural” “Healthier” water Stream Forced into stream bed delivered to river? CONROL POINTS: manmade Pipe Opportunities for recreation? Broken Down Defunct Original Natural Combination of pipe Stream Route CONTROL POINT and engineered “natural” stream bed Re-direct stream water: CONTROL POINT Local conditions may not - aquifer recharge Stream is in pipe, but has allow one or the other - irrigation not yet merged with a - small scale electrical generation combined sewer pipe. - industrial use What possibilities do these Newer Diversion Dam in Re-direct Aquifer recharge Combined Sewer Pipe stream water What are the qualities of the control points present? Irrigation aquifer? Possible Rooftop Small scale farming? This diagram breaks down River electrical generation How fast is the Newer Interceptor water moving? possible interventions at OlderCombined Sewer Pipe Sewer Outfall (Always flowing) Industrial use (Only flows during Are there existing control points. wet weather) industries in the area? CONTROL POINT Prevent sewage from entering river: CONTROL POINT Prevent sewage Divert sewage into - divert sewage into storage tank and slowly Combined sewer pipe pump to WWTP after precipitation event. from entering storage tank and slowly Waste Water flowing to outfall, river pump to WWTP after Treatment Plant downstream from dam precipitation event. diverting sewage to WWTP Interview. Spiritos, Erica. (Only flowing during precipitation events) Assistant Project Manager. Treated Sewage NYC Environmental Protection Outfall Bureau of Engineering, Design & Construction. October, 2014. “Van Cortlandt Park Master Plan 2034.” New York City Department of Parks and Recreation. 2014. Natural Streams Entering Combined Sewer Systems Geoffrey Lenat Design Research Fall 2014 Possible Interventions: Possible Interventions: “Daylighting” Irrigation/Transpiration Tibbetts Brook could be diverted Van Cortlandt Lake (the last into a reconstructed stream bed, section of Tibbetts Brook before leading directly to the Harlem it enters a pipe), is surrounded by River or other water body. If it is large areas of lawn. (The Parade not possible to rebuild the stream Grounds and the Van Cortlandt in its historic location, perhaps Golf Course) another route can be found. How much water is required to irrigate all this lawn? How can could it be diverted from Tibbetts Brook? Would irrigation water storage be necessary since Van Cortlandt Lake is adjascent. Saw Mill River Daylighting Project. Van Der Donck Park, Yonkers, New York. Photo “Van Cortlandt Park Master Plan 2034.” by Geoffrey Lenat New York City Department of Parks and Recreation. 2014. Natural Streams Entering Combined Sewer Systems Geoffrey Lenat Design Research Fall 2014 Possible Interventions: Possible Interventions: Aquifer Recharge Large Scale Retention Tibbetts Brook could be injected Van Cortlandt Lake (the last into underground aquifers. section of Tibbetts Brook before it enters a pipe), could be altered to retain water during rain events and slowly release it into the sewer pipe. This would reduce combined sewer overflow from the Broadway Sewer. http://www.onthecolorado.com/articles. cfm?mode=detail&id=1225829163240 Interview. Spiritos, Erica. Assistant Project Manager. NYC Environmental Protection Bureau of Engineering, Design & Construction. October, 2014. “Van Cortlandt Park Master Plan 2034.” New York City Department of Parks and Recreation. 2014..