An I/I investigation · 2018. 9. 6. · SSO Reduction o Upsize o Re-route o Store o Reduce peak flows BACKGROUND > 7,000 nodes > 7,000 pipes > 43,000 subcatchments

© 2015 HDR, Inc., all rights reserved.

A tail of two systemsAn I/I investigation

MARTINEZ CREEK WATERSHED

System

SanAntonioWater

SSO Reduction Program Consent Decree CIP required? SSO Reductiono Upsizeo Re-routeo Storeo Reduce peak flows

BACKGROUND

> 7,000 nodes> 7,000 pipes> 43,000 subcatchments

Literature is general and inconclusive Remediation methods can be system

specific Needed to identify root cause for our

specific Inflow and Infiltration

IDENTIFYING THE PROBLEM

Calibrated well to discrete events Difficulty calibrating to back to back events

or wet antecedent conditions

EXAMPLE FLOW METER SC12A

1.125 15.382 7.707

Other Nov 2014 Event

Urbanized 5 flow meters Sewer follows creek Creek heavily engineered

MARTINEZ CREEK WATERSHED

Downstream of three flow meters Flow meter in a manhole located in the

creek Calibrated well to smaller events Has “strange” blips for larger, more intense

events Has high parameters compared to

surrounding meters

What is causing this excessive RDII?

FLOW METER CS41

FlowMin (MGD)

Observed...) 2014 Radar May to Nov

Max (MGD)Observed...) 2014 Radar May to Nov

Volume (US Mgal)Observed...) 2014 Radar May to Nov

1.488 15.297 8.4421.#IO -1.#IO 0.0001.125 15.382 7.707

FlowMin (MGD)

Observed) 2014 Radar May to Nov

Max (MGD)Observed

) 2014 Radar May to Nov

Volume (US Mgal)Observed

) 2014 Radar May to Nov

2.062 22.687 23.4421 124 16 196 18 156

Sewer in the creek Cross connections Poor condition of pipes and manholes Maintenance (manhole lids) Other…

SOURCES OF RDII?

Location Flow Meter

CS41

Walk the creek

Numerous problems found Damaged manhole Pipes visible in creek Visible cracks in pipe

FIELD INVESTIGATION

Location Flow Meter

CS41

Issue 1Manhole Damaged

Issue 2Manhole Frame and

Cover Damaged

Issue 3Pipe in Creek with

Holes at Pipe Joints

Issue 4Pipe in Creek with no

Encasing

FIELD SURVEY FINDINGS

Built device to conduct laboratory testing of submerged manholes Manholes are leaky Manhole type affects leakiness Maintenance affects leakiness A governing equation developed for each

type of manhole

Commonly used / recommended manhole lids used within the SAWS system found to be

‘most leaky’

MANHOLE TESTING

Problem Area Field Survey Categorize Issues Manhole Testing

CS41 has CA/6 making TA/CA ~ 3% closer to area average – TA/CA was 19%

TA = Total AreaCA = Contributing Area

All major rivers and creeks modeled in HEC-RAS

Originally imported to IWRS Later converted to ICM Upper San Antonio River West Side Creeks including Martinez Creek Continual Simulation Hydrology

CREEK MODELS IN ICM

LegendOlmos CreekAlazan CreekWoodlawn East SDWoodlawn West SDApache CreekApache TributaryMartinez CreekSan Pedro CreekZarzarmora CreekZarzarmora TributaryConcepcion CreekRockwood CreekState Hospital CreekSan Antonio RiverSub-Basin Boundary

IWRS

ICM

USGS Flow Gauge on San Pedro Creek downstream of Martinez CreekCALIBRATED TO USGS FLOW GAUGE DATA

San P

edro

Cre

ek

RainfallDepth (in)

RainObservedNEXRAD PDM>5 minNEXRAD SCS>5 min

Peak (in/hr)RainObservedNEXRAD PDM>5 minNEXRAD SCS>5 min

Average (in/hr)RainObservedNEXRAD PDM>5 minNEXRAD SCS>5 min

DepthMin (ft)


Max (ft)RainObservedNEXRAD PDM>5 minNEXRAD SCS>5 min

FlowMin (ft3/s)


Max (ft3/s)RainObservedNEXRAD PDM>5 minNEXRAD SCS>5 min

Volume (ft3)RainObservedNEXRAD PDM>5 minNEXRAD SCS>5 min

5.377 3.251 0.08912.800 13600.000 172264581.2610.600 12.15027.632 14251.438 182248919.09227.634 28308.443 417485800.531

0.440 9.4310.440 14.062

Observed Stage and FlowStandard Discrete Hydrology Continual Simulation Hydrology

One ICM SE model of the Sanitary Sewer – subsurface One ICM model of the Creeks – surface How to join?

COMBINING MODELS

Cross-Connecting Sewer and Surface Flow ModelsINTEGRATED CATCHMENT MODEL

Adjusted RDII Parameters to neighboring averages

Connected Broken Manhole Connected Major DefectsConnected Manholes to Open Channels

Modeled as an Orifice• Level = 646.5• Diameter 0.8 ft• 0.8/0.45 co-eff (weir/orifice)And Sluice Gate• Level = 647.5• Width 1.0 ft• Height 0.5 ft• 0.45/0.3 co-eff (weir/orifice)

Modeled as a Sluice Gate• Level = creek bed• Width 1 ft• Height 0.05 ft• 0.3 co-eff

Modeled as Weirs• Crest = MH GL• Width 0.1 ft for leaky

(1 ft for lid blown off)• Height 0.1 ft or leaky

(0.5 ft for lid blown off)• 0.85/0.7 co-eff (weir/orifice)

0

20

40

60

80

100

120

1 13 25 37 49 61 73 85

Model InflowsEqu 1 InflowsEqu 2 InflowsEqu 3 InflowsEqu 4 InflowsEqu 5 InflowsEqu 6 InflowsEqu 8 InflowsEqu 9 Inflows

Adjusted RDII parameters to average of surrounding areas

Linked manhole to surface channel cross sections by an orifice or sluice gate

Model run and manhole leakiness compared to tested values.

Major defects then calibrated

Significant manhole submergenceMARTINEZ CREEK PROFILE

Manhole cross-connections

CS41 – Flow meter upstream of major defectsIMPROVEMENT IN CALIBRATION

RainfallDepth (in)

RainObserved...er Flow survey 2016...2 Flow survey 2016

Peak (in/hr)RainObserved...er Flow survey 2016...2 Flow survey 2016

Average (in/hr)RainObserved...er Flow survey 2016...2 Flow survey 2016

DepthMin (ft)


Max (ft)RainObserved...er Flow survey 2016...2 Flow survey 2016

FlowMin (MGD)


Max (MGD)RainObserved...er Flow survey 2016...2 Flow survey 2016

Volume (US Mgal)RainObserved...er Flow survey 2016...2 Flow survey 2016

VelocityMin (ft/s)


Max (ft/s)RainObserved...er Flow survey 2016...2 Flow survey 2016

8.320 3.120 0.0211.410 21.296 106.4880.694 2.798 1.530 5.3601.212 20.147 79.5461.120 17.820 67.012

0.465 11.1380.449 7.413

1.399 5.6891.609 5.607

More about this later

CS64 – Flow meter downstream of major defectsIMPROVEMENT IN CALIBRATION

RainfallDepth (in)


Peak (in/hr)RainObserved...er Flow survey 2016...2 Flow survey 2016

Average (in/hr)RainObserved...er Flow survey 2016...2 Flow survey 2016

DepthMin (ft)


Max (ft)RainObserved...er Flow survey 2016...2 Flow survey 2016

FlowMin (MGD)


Max (MGD)RainObserved...er Flow survey 2016...2 Flow survey 2016

Volume (US Mgal)RainObserved...er Flow survey 2016...2 Flow survey 2016

VelocityMin (ft/s)


Max (ft/s)RainObserved...er Flow survey 2016...2 Flow survey 2016

1.660 1.440 0.0042.344 100.955 201.6610.629 4.532 0.815 11.0393.782 44.064 188.0503.783 42.581 177.324

0.705 2.4150.705 2.372

3.674 7.8423.674 7.749

More about this later

Upstream meters show that the RDII from the creek causes backwater upstreamCREEK INFLOW AND INFILTRATION EFFECTS UPSTREAM

FlowMin (MGD)

ObservedJuly 17 2014.5 4 Base runs>July 17 to 18 2014...-C CS41>CC - CS41 CA/6 + Crk X mods July 17 to 18 2014

Max (MGD)ObservedJuly 17 2014.5 4 Base runs>July 17 to 18 2014...-C CS41>CC - CS41 CA/6 + Crk X mods July 17 to 18 2014

Volume (US Mgal)ObservedJuly 17 2014.5 4 Base runs>July 17 to 18 2014...-C CS41>CC - CS41 CA/6 + Crk X mods July 17 to 18 2014

0.165 5.560 1.5990.233 6.118 1.9340.233 5.418 1.934

Model simulations during calibration shows tailwater effects

Peak flow estimated and checked against observed depthSOME METERS HAD ISSUES WHEN SURCHARGED

DepthMin (ft)

Observed... FM Investigation DWF... FM Investigation DWF... FM Investigation DWF

Max (ft)Observed... FM Investigation DWF... FM Investigation DWF... FM Investigation DWF

FlowMin (MGD)


Max (MGD)Observed... FM Investigation DWF... FM Investigation DWF... FM Investigation DWF

Volume (US Mgal)Observed... FM Investigation DWF... FM Investigation DWF... FM Investigation DWF

VelocityMin (ft/s)


Max (ft/s)Observed... FM Investigation DWF... FM Investigation DWF... FM Investigation DWF

1.264 19.985 41.9861.320 12.638 0.400 5.941-16.602 25.030 41.966-16.602 25.030 50.0771.283 19.568 50.082

0.420 9.7680.420 10.7200.420 1.853

-4.055 6.740-4.055 6.7403.457 7.162

Assessing magnitude of RDII

How much RDII is likely from Creek intrusion?

Fixing Defects:Incremental improvement in system. At what point do you see improvements?

Removing line from Creek:

Reduction in RDII

HOW THIS WAS USED – 5 YEAR 6 HOUR ANALYSIS EVENT

0

5

10

15

20

Broken Manhole

Flow

Rainfallpth (in)

Peak (in/hr)

Average (in/hr)

FlowMin (MGD)

Max (MGD)

.180 6.120 0.0911.979 11.4561.177 22.0141.177 22.4261.177 22.4991.177 20.9181.177 20.1021.128 18.828

ed

2014 Radar CS64>SCS July 17 to 18 2014SCS + 13692 surface-sewer July 17 to 18 2014>SCS+13692 s-s recal CS62 July 17 to 18 2014

rtinez>SCS surface-sewer July 17 to 18 2014 >SCS-13692 s-s recal CS62 July 17 to 18 2014

ed



ed



Flow meter dataCalibrated Model

Calibrated model with x-link to creek modelTweaked Cal of CS62 and CS41 with x-link to creek

Tweaked Cal with Full x-link to creek modelTweaked Cal with x-link removed

ObservedBaseHole fixedPipe fixed½ MH fixedAll MH fixedSystem tightened

Flow (MGD)11.45622.01422.42622.49920.91820.10218.828

Min (MGD)

1.9793.2372.7432.7433.2374.4443.3012.808

Effect on CIP work if not addressed:

Creating capacity downstream allows more inflow from creek

Flow meter dataCalibrated Model

Calibrated model CIP D/SRun 2Run 3Run 4

CS14 and CS15 in the Martinez Creek WatershedMICRO-CALIBRATION USING GROUND WATER INFILTRATION

Identifying excessive RDII areas Two chosen are in the Martinez Watershedo CS14o CS15

Documented history of SSOso Number of SSOs significantly higher than system

average Flow monitor peaking factor analysis indicated

clear wet weather response Model calibration parameters higher than average

MICRO-CALIBRATION

Model calibrates well to discrete events but not so well to back to back eventsMICRO-CALIBRATION

RainfallDepth (in)

RainObserved...alSpine_0%>CS14 (FNI CSSE) DWF

t h t NEXRAD 5 2015 2017

Peak (in/hr)RainObserved...alSpine_0%>CS14 (FNI CSSE) DWF

t h t NEXRAD 5 2015 2017

Average (in/hr)RainObserved...alSpine_0%>CS14 (FNI CSSE) DWF

t h t NEXRAD 5 2015 2017

FlowMin (MGD)

RainObserved...alSpine_0%>CS14 (FNI CSSE) DWF

t h t NEXRAD 5 2015 2017

Max (MGD)RainObserved...alSpine_0%>CS14 (FNI CSSE) DWF

t h t NEXRAD 5 2015 2017

Volume (US Mgal)RainObserved...alSpine_0%>CS14 (FNI CSSE) DWF

t h t NEXRAD 5 2015 2017

2.689 2.403 0.0280.076 0.622 0.8790.056 0.204 0.5130 057 0 497 0 655

Rainfall

Depth (in)

RainObserved...I CSSE) DWF...m 2015-2017

Peak (in/hr)


Average (in/hr)


Flow

Min (MGD)


Max (MGD)


Volume (USMgal)


1.902 3.640 0.1270.086 1.248 0.1790.056 0.204 0.0770.057 1.291 0.202

Rainfall

Depth (in)

RainObserved...FNI CSSE) DWF... 5m 2015-2017

Peak (in/hr)


Average (in/hr)


Flow

Min (MGD)


Max (MGD)


Volume (USMgal)


3.349 2.166 0.1240.062 1.447 0.4360.056 0.204 0.1360.056 1.260 0.342

CS14_01

CS14_02

CS14_03

CS14_04

CS14_05

CS14_06

CS14_07

Applying Ground Infiltration module to fill in



INFILTRATION ZONEInitial calibration indicated that the highlighted area (CS14_02, CS14_05 and CS14_06) shows signs of increased infiltration for longer events.

RainfallDepth (in)

RainObserved...ralSpine_0%>CS14 (FNI CSSE) DWF...Catchment NEXRAD 5m 2015-2017

Peak (in/hr)RainObserved...ralSpine_0%>CS14 (FNI CSSE) DWF...Catchment NEXRAD 5m 2015-2017

Average (in/hr)RainObserved...ralSpine_0%>CS14 (FNI CSSE) DWF...Catchment NEXRAD 5m 2015-2017

FlowMin (MGD)

RainObserved...ralSpine_0%>CS14 (FNI CSSE) DWF...Catchment NEXRAD 5m 2015-2017

Max (MGD)RainObserved...ralSpine_0%>CS14 (FNI CSSE) DWF...Catchment NEXRAD 5m 2015-2017

Volume (US Mgal)RainObserved...ralSpine_0%>CS14 (FNI CSSE) DWF...Catchment NEXRAD 5m 2015-2017

2.697 2.403 0.0230.055 0.622 0.9960.056 0.204 0.6360.056 0.497 0.772

Source: Innovyze help topic “Ground Infiltration Model”

Rainfall runoff has three model components: • initial loss (depression storage)• runoff volume • runoff routingIncident rainfall is initially stored in surface depressions, which are subject to evaporative loss (defined in the rainfall event).

When rainfall exceeds depression storage in a given time step, a proportion of the excess rainfall goes to runoff according to the particular volume model used. The remaining rainfall is directed into the soil storage reservoir (1).

When the soil reaches a given saturation threshold (the percolation threshold - 2), water starts to percolate downwards. A proportion of this percolation flow (the percolation percentage infiltrating - 3) infiltrates directly into the network while the remainder penetrates deeper to feed the groundwater storage reservoir (4).

Note that the volume in the soil storage reservoir is also subject to evapotranspiration, though at a reduced rate.

The Ground Store will effectively be turned off and not influence the results

RUNOFF + GROUND INFILTRATION(SOIL STORE)

Percolation threshold Percolation coefficient

Percolation percentage infiltrating

Infiltration coefficient Infiltration threshold type Infiltration threshold level (ft / ft AD)

Baseflow coefficient Baseflow threshold type Baseflow threshold level (ft / ft AD)

Evapotranspiration type Evapotranspiration depth (ft)

Porosity of soil Soil depth (ft)

Porosity of ground

(Value)(1 – Value)

Runoff (RDII)

Infiltration to Soil Store

Loss to Baseflow(losses from groundwater store that do not enter drainage network)

Ground Store Inflow

Soil Store InflowSoil Store Depth

Ground Store LevelGround Water Inflow

=Soil Store Inflow

+Ground Store Inflow

Infiltration to Ground Store

Surface Hydrology

Ground Store

Soil Store

Confirm the surface hydrology RDII parameters for maximum effecto VPR (Wallingford with Variable Percentage Runoff – NewUK Soil Depth)o Soil Type Set (1 - 4) o Evaporation Set (recommend monthly profile)o API Set (Antecedent Precipitation Index – use software)

NOT JUST GWI

March 2018MORE INFLOW AND INFILTRATION THAN EXPECTED

0.68 in 0.037 MG

0.88 in 0.241 MG

0.73 in 0.344 MG

0.83 in 0.29 MG

RainfallRDII

2018 rains with increased RDII responseTHEN TO ADD TO THE PROBLEM

RainfallDepth (in)

RainObserved...ment NEXRAD 5m 2017-2018 Evap...ment NEXRAD 5m 2017-2018 Evap

Peak (in/hr)RainObserved...ment NEXRAD 5m 2017-2018 Evap...ment NEXRAD 5m 2017-2018 Evap

Average (in/hr)RainObserved...ment NEXRAD 5m 2017-2018 Evap...ment NEXRAD 5m 2017-2018 Evap

FlowMin (MGD)

RainObserved...ment NEXRAD 5m 2017-2018 Evap...ment NEXRAD 5m 2017-2018 Evap

Max (MGD)RainObserved...ment NEXRAD 5m 2017-2018 Evap...ment NEXRAD 5m 2017-2018 Evap

Volume (US Mgal)RainObserved...ment NEXRAD 5m 2017-2018 Evap...ment NEXRAD 5m 2017-2018 Evap

26.209 4.533 0.0030.000 1.513 20.4950.021 0.711 20.1430.021 0.880 21.051

CS14_01

Micro-calibration parametersMicro-calibration parameters plus Ground Infiltration Module

• Modeling results are directing the extent and prioritization of pipeline renewal efforts

• Results showing the degree of improved Level of Service identified in these pilot remediation basins are to be used as benchmarks for other targeted remediation areas in the system

• Post renewal monitoring will be used for future model parameters (re-calibration)

OUTCOMES

Matthew Schorsch, P.E.San Antonio Water SystemMaster [email protected]

THANK YOU

Anthony HenryAssociate / Senior Hydraulic ModelerHDR [email protected]

mailto:[email protected]

mailto:[email protected]

Documents

An I/I investigation · 2018. 9. 6. · SSO Reduction o Upsize o Re-route o Store o Reduce peak flows BACKGROUND > 7,000 nodes > 7,000 pipes > 43,000 subcatchments