real-time low-flow forecast system (lffs) for the …€¦ · real-time low-flow forecast system...

Real-Time Low-Flow Forecast System (LFFS)

for the Potomac River Basin

Cherie Schultz1, Ross Mandel, and Sarah Ahmed1

Interstate Commission on the Potomac River Basin (ICPRB)1Section for Cooperative Water Supply Operations on the Potomac (CO-OP)

Ian Maycumber and Michael ThiemannRiverside Technology, inc

AWRA Annual MeetingNovember 6, 2014

Reston, Virginia

Presenter

Presentation Notes

My name is Cherie Schultz. I work for ICPRB, and I work in a section of the Commission that deals with water supply of the Washington, DC metropolitan area, the Section for Cooperative Water Supply Operations on the Potomac. The Potomac River is the region’s primary water supply source. So today I want to talk about some work being done to develop a new flow forecast model for the Potomac – with a focus on low flows. A lot of people have helped make this effort happen …

Overview

Developing Low Flow Forecast System (LFFS) to support Washington metropolitan area water supply drought operations Project partners ICPRB Riverside Technology, inc.

With assistance from Middle Atlantic River

Forecast Center (MARFC) Chesapeake Bay Program

(CBP)

Presenter

Presentation Notes

Our objective is to develop a real-time stream flow forecast system for low-flow conditions – to support WMA drought operations. How serious an issue is drought in this region? Water is usually plentiful in the eastern portion of the US, but droughts do occur, periodically. Water supply planning and management in our region is driven by drought conditions.

Background

Washington metro area has 3 major water suppliers75% of supply from

Potomac RiverSuppliers cooperate

during droughts joint funding of storage

in upstream reservoirs coordinated operations assistance from ICPRB

CO-OP Section

Potomac intakes

Washington

PA

MD

VA

WV

Presenter

Presentation Notes

Some background on water supply in the WMA: This area has a regional cooperative system of water supply management during droughts. There are 3 major suppliers - (CLICK) see map for areas served. 75% of supply is from Potomac River – (CLICK) see map – all of the suppliers have intakes on the river at locations upstream of DC. 3 suppliers relying on one source during droughts could be a recipe for conflict, but, WMA has a cooperative system of water supply management during droughts, based on a set of agreements put in place 30 years ago.

Need

Upstream reservoirs augment Potomac River flow during droughtsTravel times for releases

are significant 8 – 9 days from far

upstream reservoirs 1 – 1 ½ days from local

reservoirRiver flow is highly

variableBetter flow forecasts –

better system efficiency

Washington

PA

MD

VA

WVLittle Seneca

Reservoir

Jennings Randolph Reservoir

Savage Reservoir

Potomac intakes

Presenter

Presentation Notes

The WMA’s cooperative system relies on reservoirs to augment Potomac River flow during droughts. TOT significant and flow variable. So good flow forecasts are key to efficient use of reservoir storage. Currently we rely on upstream gage data and fairly conservative assumptions to determine release rates, but we would like to do better.

Goals

Construct a real-time flow forecast tool use CBP Watershed

Model to predict flows

use available real-time meteorological data

Enhance the model’s predictive capabilities for low flows

Map of upper Potomac River basin, showing Oct 28-29 precipitation data from the National Severe Storm Laboratory (NSSL)

CBP Watershed Model

Open source

HSPF-based

Used for Bay TMDL

Key summer-time inputs

Precipitation

Temperature

ET

Chesapeake Bay

Presenter

Presentation Notes

Provides nutrient and sediment loads for the Bay water quality model.

CHPS/FEWS(Community Hydrologic Prediction System/Flood Emergency Warning System)

Based on Deltares open interface modeling platform – FEWS

Customized by the National Weather Service – CHPS

In use by NWS River Forecast Centers

Designed to foster collaboration

Presenter

Presentation Notes

Deltares is a water research institute in the Netherlands. “CHPS is NOAA’s customized application of FEWS”

Metro area withdrawals• Recent• Future scenarios

Chesapeake Bay Program

Watershed Model

CHPS/FEWS (Community Hydrologic

Prediction System)

Meteorological data• Recent• Forecasted

Reservoir releases• Actual/simulated• Future scenarios

LFFS Components

Potomac Riverflow forecasts

LFFSObserved Meteorological Data

MARFC (including multi-sensor precipitation estimates)

NASA’s North American Land Data Assimilation System (NLDAS)

National Severe Storm Laboratory (NSSL)

NWS’s HydrometeorologicalAutomated Data System (HADS)

Presenter

Presentation Notes

Riverside helped us navigate the many NWS products and acronyms. The LFFS provides us with multiple data sets – both to allow evaluation, and to ensure that there is backup data available during operations. HADS – Hydrometeorological Automated Data System; NSSL – National Severe Storms Laboratory – Q2: The Q2 system moves toward a multi-sensor approach focused on high-resolution integration of radar, satellite, model, and surface observations to produce very high-resolution precipitation estimates.

LFFSForecasted Meteorological Data

MARFC’s 3-day quantitative precipitation forecasts (QPFs)

National Digital Forecast Database (NDFD) 3-day QPFs

Weather Prediction Center (WPC) 7-day QPFs

Global Ensemble Forecast System (GEFS) 15-day forecasts

Presenter

Presentation Notes

All of the QPF’s are provided at 6-hr intervals. NDFD – National Digital Forecast Database – note that it seems to provide: T, max & min T, P, cloud cover, dew point, wind speed, max & min relative humidity, sky cover, snow amount. GEFS – Global Ensemble Forecast System

LFFSMerged Meteorological Data Inputs

Meteorological inputs are hourly by Watershed Model “land segments”

Riverside’s “prioritization” scheme selects data based on:

availability

quality

LFFSOther Data Inputs

USGS real-time streamflow data

Hourly WMA supplier withdrawals

Monthly upstream withdrawals & discharges

Releases from reservoirs

LFFSFlow Forecasts

LFFSVisual Tools

LFFS Status

First version completed April 2014

“Live” model Updating continuously on ICPRB’s Linux server Accessible on multiple PC’s via “Operator-Client” user interface

“Stand-alone” models Independent copies of LFFS that can be run manually

Can be used for research and development

ICPRB conducting tests & evaluations

ICPRB’s First Impressions

CHPS/FEWS robust

flexible & modifiable (based on xml & python files)

may facilitate info exchange with River Forecast Centers

Real-time meteorological data & forecasts wide array of products

constantly evolving

Real-time use of CPB Watershed Model CHPS/FEWS visual tools valuable

summer 2014 raw flow predictions disappointing

Future Directions

Short-term Compare performance of various precipitation datasets

Implement access to MARFC’s new streamflow ensemble forecasts

Longer-term Develop “data assimilation” algorithms

Improve reservoir release simulations

Investigation of low-flow sensitivitiesWater withdrawal & discharge inputs

Groundwater discharge algorithm (see JAWRA – Sep 2014)

Surface evaporation/riparian ET Channel routing

real-time low-flow forecast system (lffs) for the …€¦ · real-time low-flow forecast system...

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