CONFIDENTIAL

CONFIDENTIAL

Reliable Resilient Real-time Flood Warning Network

James Logan, OneRain,

Flood Warning

Summary

• What is in a real-time monitoring network?

• How can it be made it reliable and resilient?– Identify single points of failure, options for

mitigating single points of failure– Based on risk and cost, implement

redundancy where it makes sense

Components of the Real-Time Environmental Monitoring System

                                                                                                                                                                                 What make a real-time monitoring network?

What does it mean to be reliable and resilient?

• Reliability is the achieved outcome– It is up every time it is needed– Data is available anytime/anywhere

• Resiliency lies in the design and maintenance• Design minimizes single points of failure

• Strong maintenance practices and tracking help achieve accountable performance

Telemetry

• Affordable and sustainable– Power management, cost, vandalism issues

• Timely delivery– Flash flooding requires real-time data

• Reliable paths– RF and network

• Redundant paths increase data reliability

• Gauge Site Failures– Is redundancy required here?– If you lose a sensor, will your operations

fail?

• Repeater Failures– If you lose a repeater, what data are lost?

Analyze for points of failure

• Base Station Failures– Power, antenna, receiver, decoder; Will one

failure take the system down?– Connectivity for dissemination; How many

users are impacted? Will alarms go out?

Analyze for points of failure

Reliable networks are designed to avoid single points of failure

• Move single points of failure out to gauges

• Redundant telemetry at repeater sites– Independent receive/transmit, different data

channels (ALERT, satellite, IP, cell, ALERT2™)

• Redundant data receive sites– Geographically distributed, diverse mechanisms

Mitigating missing rain gauges

• Importance of rain gauges– If a gauge does not participate, you have lost that

area of rainfall monitoring, could be a critical catchment

• GARR lessens impact of lost rain gauges– Gauges used to calibrate radars superior spatial

coverage– No loss of information at gauge that failed, less

certainty of overall accuracy than with the gauge

Rain gauges vs. gauges + radar

Gauge-only rainfall estimates

Gauge-adjusted radar rainfallestimates

Reliable networks are well-maintained, their performance held accountable

• Solid, standardized maintenance practices– Routine/proactive scheduled maintenance– Good trouble recognition and troubleshooting– Daily analysis of data, statistical tools

• Performance accountability– Daily/monthly/annual reporting to show

sensor, network availability

Data collection & dissemination

• Reliable/redundant receive points– Safe archiving once data arrive– Lost gauge data are irreplaceable

• Accessibility– Anytime/anywhere access– Usability

• Appropriate security– Authorized users? What should the public see?

Real life examples

Los Angeles County

• Redundant repeater path• ALERT RF and StormLink™ Satellite

Concentrators at Repeaters• Redundant base stations

• DIADvisor™ and Contrail® Web for Base Station Redundancy

Denver Urban Drainage and Flood Control District

• Redundant repeater path• ALERT RF and ALERT2™ at Repeaters

• Redundant base stations• Mission critical customer agencies of UDFCD

have their own base station receiver and software as backup to UDFCDs website

Monterey County

• Repeater Redundancy• ALERT RF and StormLink™ IP Concentrator

at repeater• Base Station Redundancy

• Local DIADvior™ Base Station and Contrail® Web for base station redundancy

Napa County

• Repeater Redundancy• ALERT RF and StormLink™ Satellite

concentrator at repeater• Base Station Redundancy

• Local DIADvisor™ Base Station and Contrail® Web for base station redundancy

Summary

• Identify single points of failure

• Investigate options for reducing single points of failure– Network backbone– Base Stations

• Based on risk and cost, implement redundancy where it makes sense

Thanks!

Questions?

CONFIDENTIAL

StormLink™ Satellite Telemetry

• L – Band• 20 second latency• Independent channel• Independent

infrastrucure– Contrail® Web

StormLink™ rainfall example

Remote Site

VPN Tunnel

Radar Data gauge Data

Customized Products

MSAT Satellite

DownlinkReston, VA

Internet

TCP/IP

X.25

X.25

Contrail® clientClient Application (DIADvisor™, other)

XMLhttp

Network Evaluations• Harris County, TX

• Louisville MSD, KY

• Overland Park, KS

• Clark County, NV

• Denver Urban Drainage and Flood Control District

• Southern CA ALERT Network (SCAN)

• Maricopa County, AZ

• Entergy Corporation

• Site design issues, for example:– Good capture by rain gauge?– PT in the water at low levels? – Vulnerability to high flows?

• Representative monitoring, for example:– Rainfall – are gauge data used alone or to

calibrate radar (don’t need as many gauges with GARR)?

Monitoring components

BOR/BIA Dam Safety Project

• Since 2004• 130+ high risk, high

hazard dams• Contrail® Web with

automated alarms & notifications

• Supporting National Monitoring Center, staffed 24/7

Louisville/Jefferson County MSD

• Since 2003• Real-time control support• MSD, USGS and METAR

gauges• OneRainware™ GARR

– Real-time, 4-hour forecast

• Contrail® Web with automated alarms & notifications

StormLink™ rainfall example

Remote Site

VPN Tunnel

MSAT Satellite

DownlinkReston, VA

Internet

TCP/IP

X.25

X.25

Contrail® clientClient Application (DIADvisor™, other)

XMLhttp