San Antonio River Authority’s Bexar County Flood Warning System · 2013-07-09 · SARA’s Bexar...

San Antonio River Authority’sBexar County Flood Warning System

Curtis Beitel, P.E., CFM

ASFPM 2013 Conference

June 2013

SARA’s Bexar County Flood Warning System June 2013 2

Project Overview

• Only FloodWorks in U.S.

• Implemented Salado Creek

Pilot Study in June 2011

• San Antonio River

– 50 locations

• Leon Creek

– 30 locations

• Medina River

– 20 locations

• Cibolo Creek

– 20 locations

• Salado Creek update


Traditional Flood Forecasting System

Flood Warning Server

Level

Gauge

SCADA/ telemetry database

Client

s

Management of real-time data from the field

– importance of decent data quality

Preparation of these

data for input to the

forecasting model

Forecast runs with real-time updating

procedures to improve forecasts based

on observed data

Dissemination

module, using

fax, email, SMS

and internet

Rain Gauge

& NEXRAD

Timely: Available in the shortest possible time from measurement of the precipitation in the catchment

Accurate: Both the authorities preparing emergency action and the vulnerable people need confidence in the system

Reliable: Capable of functioning in the severe conditions that prevail during storms and disasters

Adaptable:Able to take account of the impacts of physical changes in the catchment


Operational Diagram

• 2 Processes– Hydrometric DB

– Event Manager

• Automatic– Low = Every 6 hours

– High = Every 15 minutes

– 24/7

• Runs– InfoWorks RS

– InfoWorks CS

– InfoWorks SD

Source: FloodWorks Version 13.0 Users Manual, Innovyze, July 2012


Hydrology

Rainfall and

Potential

Evaporation

Runoff

Probability Distributed Model

(PDM)

Soil

Moisture

Routing Reaches

(Olmos Watershed)

Simplified Runoff

Model (SRM)

Runoff

RS Hydraulic Model

(SAR Watersheds)

Rainfall

• 2 Processes

– Probability Distributed Model

– Simplified Runoff Model

• Probability Distributed

Model

– Estimates soil moisture from

gaging station

• Simplified Runoff Model

– Uses soil moisture to generate

runoff hydrographs at

ungauged locations


Hydrology - PDM

• Probability Distributed

Model

– Requires real time gaging

station

– Estimates soil moisture


Hydrology – PDM Calibration

Model ComponentPara-

meterUnit Description Function

General

fc none rainfall factor controls runoff volume

td h time delay shifts hydrograph along time axis

kinf mm/hr Infiltration ratedecrease kinf to increase infiltration-

excess runoff

Probability Distributed

Storage Area

cmin mm minimum and maximum storage

capacityaffect time of onset of runoff, also

feeds back to evaporation and recharge

rates

cmax mm

b none

exponent of Pareto distribution

controlling spatial variability of storage

capacity

Evaporation Function be none exponent in actual evaporation functionaffects variation between seasons or

years

Standard Recharge

Function

kg h mmbg-1 groundwater recharge time constant controls rate of aquifer recharge

bg none exponent of recharge functionincrease to magnify sensitivity of

recharge rate to soil dryness

St mm soil tension storage capacity

increase to prevent complete drainage

of soil moisture storage area and

maintain evaporation

Surface Routingk1 h time constants of cascade of two linear

reservoirscontrols peakiness of hydrograph

k2 h

Groundwater Storage

Routing

kb h mmm-1

baseflow time constant

(m: exponent of baseflow non-linear

storage)

controls length of recession

qc m3s-1constant flow representing

returns/abstractionsshifts hydrograph along flow axis

Table adapted from: CEH Wallingford, A practical User Guide to the PDM, Technical Paper. October

2002 and CEH Wallingford, The Probability Distributed Model, Technical Paper, 2000.



0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

1/1

/19

98

7/2

/19

98

1/1

/19

99

7/2

/19

99

1/1

/20

00

7/1

/20

00

12

/31

/20

00

7/1

/20

01

12

/31

/20

01

7/1

/20

02

12

/31

/20

02

7/1

/20

03

12

/31

/20

03

6/3

0/2

00

4

12

/30

/20

04

6/3

0/2

00

5

12

/30

/20

05

6/3

0/2

00

6

12

/30

/20

06

6/3

0/2

00

7

12

/30

/20

07

6/2

9/2

00

8

12

/29

/20

08

6/2

9/2

00

9

12

/29

/20

09

6/2

9/2

01

0

12

/29

/20

10

6/2

9/2

01

1

12

/29

/20

11

6/2

8/2

01

2

12

/28

/20

12

Da

ily

Me

an

Dis

cha

rge

(cf

s)

Date

USGS Discharge Data

SAR Lower 08178565

SAR Upper 08178050

Olmos 08177700

Calibration Event



0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.00

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

Rai

nfal

l R

ate

(in/

hr)

Dis

char

ge (c

fs)

Date / Time

Observed Flow (cfs)

Computed Flow (cfs)

Rainfall Rate (in/hr)

Olmos Creek at Dresden Drive - September 2010 Event



San Antonio River at Mitchell Street - September 2010 Event

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.00

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

Rai

nfal

l R

ate

(in/

hr)

Dis

char

ge (c

fs)

Date / Time

Observed Flow (cfs)

Computed Flow (cfs)




San Antonio River at Loop 410 - September 2010 Event

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.00

10,000

20,000

30,000

40,000

50,000

60,000

70,000

Rai

nfal

l R

ate

(in/

hr)

Dis

char

ge (c

fs)

Date / Time

Observed Flow (cfs)

Computed Flow (cfs)



Hydrology - Simplified Runoff Model

• Generates runoff

hydrographs

• Basin average rainfall P

• Effective rainfall Re

– Re = P x C x (1-SMD)

– SMD = soil moisture deficit

• Converted to runoff Q

– 2 linear reservoirs

– Q = Re x (1-e-t/K)

• Q input into InfoWorks RS

– At a point

– Distributed over reach


Hydraulics - Overview

• San Antonio River

– 48 miles

• Leon Creek

– 59 miles

• Medina River

– 39 miles

• Cibolo Creek

– 17 miles

• Salado Creek

– 20 miles

• Total = 183 miles


Hydraulics - Comparison

• DFIRM RAS models

– As detailed as possible

– Steady peak flow rate

– Focused on 100-year

– 1D flow

– Hydrologic routing

– English units

• InfoWorks RS models

– Match RAS within 0.5 feet

– Unsteady, Full range of flows

– Balanced focus (low & high)

– 1D with multiple flow paths

– Dynamic channel routing

– Metric units


Hydraulics - Processes

• Simplified RS models

– Run within 15 minute window

• Starts with DFIRM RAS

– Review / refinement

– Delete unnecessary sections

• Import into RS

• Steady RS (low flows)

• Unsteady RS (HMS flows)

• Add structures 1 at a time

• Compare RAS vs. RS

• Optimization


Hydraulics - Challenges

• Complex split flow areas

– Martinez Creek



• Undersized storm drains

– Apache Creek

– Concepcion Creek



• Flow through

neighborhoods

– Apache Creek

– Concepcion Creek

• Series of storage

areas in InfoWorks RS



• Flood Control Tunnel Operations

– San Pedro Creek Tunnel

– San Antonio River Tunnel


Real Time Adjustments

• State-updating & error prediction: Compares observed data

with the corresponding model outputs and uses this

information to update and improve the model forecasts:

– State-correction

– Error-prediction

• Quick real time update

• Available for operations

• Confidence in system


Rainfall Forecast Options

• Quantitative Precipitation

Forecasts

• 1 hour to 5 days

• GIS-based spatial/volume input

• Forecast information from

– NWS/NOAA

– Private sector

• Developing a library of rainfall

profiles

– SARA staff to select

– NWS/NOAA to provide

http://www.nssl.noaa.gov/projects/q2/q2.php


Interactive Website at EOC


Details at Warning Location

• Local web design sub– Updated

SAOEM site

• Current and concise data

• SAOEM EOC

• SAFD Dispatch

• Swift Water Rescue

• SAPD/Sheriff evacuations


Location Maps


Real Time Inundation Mapping

Overall Maximum

Water

Velocity

Water Depth

• Limited

number of

locations

• Road

closures

• Evacuation

limits


Project Schedule

• Salado Pilot Study – June 2011 – by AGT & HR Wallingford

• Notice to proceed - April 2012

• Initial Salado Website – January 2013

• San Antonio

– RS models – January 2013

– Calibration – April 2013

– Website – July 2013

• Leon Creek

– RS models – April 2013

– Calibration – July 2013

– Website – September 2013

• Medina Creek / Cibolo Creek / Salado Update

– Website – December 2013


Questions & Answers

Overall Maximum

Water

Velocit

y

Water

Depth

San Antonio River Authority’s Bexar County Flood Warning System · 2013-07-09 · SARA’s Bexar...

Documents

Transcript of San Antonio River Authority’s Bexar County Flood Warning System · 2013-07-09 · SARA’s Bexar...