Water Management decision tool for New York City

Client: New York City Department of Environment Protection
Location: New York City
Period: 2011 – Present

Project Summary

New York City is faced with decisions about how to provide clean water to its residents. Options considered include the construction of major water filtration facilities, at a cost in the range of $10-20 Billion, or improved management of existing water supplies based on forecasts of water amounts and quality, at a cost in the range of $10-15 Million. The New York City Department of Environmental Protection (NYCDEP) is pursuing the latter solution in implementing an Operations Support Tool (OST).

Project Details

Riverside is providing support for the development of the OST. This tool will provide a state-of-the-art Decision Support System to improve NYCDEP's ability to operate its water supply and delivery system. It will provide NYCDEP with the data and analytical tools needed to manage water supply system reliability, drinking water quality, and environmental and regulatory requirements on a daily basis.

Riverside’s role in this project includes:

• Deployment of a data acquisition and processing system

  NYCDEP operates an extensive SCADA system to monitor its water supply and delivery system. Furthermore, third party contractors to obtain water quality and meteorological observations with additional hydrologic data obtained from the United States Geological Survey (USGS) and the National Weather Service (NWS). Riverside developed flexible and transparent import, data quality control, and filling routines using its TSTool software and a central RiversideDB database. This operational system provides the OST and other NYCDEP users with easy and flexible access to real-time raw and processed data.

• Historical and real-time data analysis

  NYCDEP has developed an extensive historical flow record for key locations in their water supply and distribution system. Although these data have proven to be very valuable, uncertainty in these records have a negative impact on OST modeling and forecast performance. Using TSTool, Riverside is working with the NYCDEP to improve the consistency and quality of these data.

• Model calibration

  The OST requires streamflow forecasts from the NWS as input to its reservoir simulation processes. The NWS Northeast River Forecast Center (NERFC)and Middle Atlantic River Forecast Center (MARFC) provide short term deterministic forecasts and long term Ensemble Streamflow Predictions (ESP) for most critical locations in NYCDEP's water supply system. To provide forecast for all locations, Riverside computed historic time series of mean areal precipitation (MAP) and mean areal temperature (MAT), and calibrated the National Weather Service (NWS) Hydro-17 Snow Accumulation and Ablation Model (SNOW-17), the Sacramento Soil Moisture Accounting Model (SAC-SMA), and the Unit Hydrograph Model (UNIT-HG) for sub-basins in the Croton River Basin in New York State.

• Forecast post processor development

  Together with Dr. John Schaake, Riverside developed an Ensemble Post-Processor (EPP) to reduce the biases in the ESP traces generated by the NERFC and the MARFC. The EPP is based on an approach proposed by Dr. John Schaake (Lingling et al, 2010) and uses the statistical relationships between historical flow observations and model simulations and a general linear model (GLM) to adjust existing ESP traces and create ensembles for (nearby) locations where no ESP data are available.

• Software development support for the OST user interface