presentation to nueces bbasc sam vaugh, pe cory shockley ......presentation to nueces bbasc . sam...

Presentation to Nueces BBASC Sam Vaugh, PE

Cory Shockley, PE – HDR Engineering May 23, 2012

1

April 23rd Discussion Instream Flow

Planned Water Supply Project Evaluations Sabinal Recharge Dam

Standard and Strategy Evaluation Nueces River @ Laguna Nueces River @ Cotulla

Yield vs. e-flow regime Recommendation

Develop Modified BBEST W Ecological and sediment analysis

Modified BBEST A Modified BBEST W

2

April 23rd Discussion Nueces Bay & Delta

Planned Water Supply Project Evaluations Lake Corpus Christi Off Channel Reservoir

B&E Scenario Evaluation Yield Average Bay Inflow

Path Forward Evaluate scenarios to recommend attainment frequencies of

meeting the BBEST targets that allow for the balance for human needs.

3

Discussion Instream Flow

HDR Summary of April 23rd Analysis Presentation of Modified BBEST W

BBEST Presentation of Aquatic Habitat Analysis

TWDB Presentation of Sediment Analysis

BBASC vote to adopt an e-flow regime

4

Discussion Nueces Bay & Delta

B&E Scenario Evaluation BBEST Recommendation Agreed Order Safe Yield No Pass-Thru’s OCR Order Safe Yield

Yield Attainment Frequencies Salinity

BBASC vote to adopt an e-flow regime

5

Focal Sites for BBASC Instream Flow Standard Recommendations

6

Defined – Modified BBEST Overbank Exemption Pulse Exemption Rule

diversion rate < 20% of the flow pulse trigger 20% rule not applicable to on-channel reservoirs

Single Tier of Base Flows with 50% Rule Diversions may not exceed 50% of the difference

between the base flow and the subsistence flow. Evaluated Wet and Average Base Flow Tiers

7

Sabinal River near Sabinal

8

9

36% 36%

81%

36%

81% 81%0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

No E-FlowRestrictions

Lyons CCEFN Modified BBEST W

Modified BBEST A

Full BBEST

Aver

age

Annu

al En

hanc

ed R

echa

rge (

acft

/yr)

Sabinal River at Sabinal Recharge Reservoir - Enhanced Recharge

Long Term Avg (1934-1996)

Drought Avg (1947-1956)

10

0

50

100

150

200

250

300

350

400

450

500

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Flow

(cfs

)

Percentage of Time Flows are Equaled or Exceeded

Sabinal River at Sabinal Recharge Reservoir - Flow Frequency Curve

Historical

Full BBEST

Modified BBEST A

Modified BBEST W

No E-Flow Criteria

Period of Record: 1/1/1934 to 12/31/1996Period of Record: 1/1/1934 to 12/31/1996

Sabinal Recharge Dam Preliminary Conclusions

The impoundment of high flow pulses by the Sabinal Dam provides the greatest opportunity for recharge enhancement.

Variations in base flow criteria have negligible effects on enhanced recharge.

Downstream Impacts System yield = -1,900 to -2,300 acft/yr Average Annual Bay Inflow = -850 acft/yr

11

Standard & Strategy Evaluation Laguna ROTR with OCR Cotulla Reservoir Cotulla ROTR with OCR Evaluate:

No Recommendation BBEST Recommendation Modifications to BBEST Recommendation

Results: Yield Streamflows

12

Nueces River @ Laguna - BBEST

13

Overbank Events

Subsistence Flows (cfs)

Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov

Pulse volumes are in units of acre-feet and durations are in days.Period of Record used : 1/1/1924 to 12/31/2009.

Qp: 15,600 cfs with Average Frequency 1 per 5 yearsRegressed Volume is 124,000

Duration Bound is 107

High Flow Pulses



Winter Spring Summer Fall

44 32 41

14 18 16 14

Qp: 2,220 cfs with Average Frequency 1 per yearRegressed Volume is 18,400


Base Flows (cfs) 48 65

Flow Levels

High (75th %ile)

Medium (50th %ile)

Low (25th %ile)

Subsistence

5165

Qp: 590 cfs with Average Frequency 2 per yearVolume Bound is 11,300Duration Bound is 26

Qp: 48 cfs with Average Frequency 1 per season

Volume Bound is 1,000Duration Bound is 7

Qp: 390 cfs with Average Frequency 1 per seasonVolume Bound is 6,070Duration Bound is 17


Qp: 50 cfs with Average Frequency 1

per seasonVolume Bound is 800Duration Bound is 5


76 9292

14

54% 58% 61% 62%69%

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

No E-Flow Criteria Lyons CCEFN Modified BBEST A Modified BBEST W

Full BBEST

Firm

Yie

ld (a

cft/

yr)

Nueces River at Laguna OCR - Firm Yield

15

0

50

100

150

200

250

300

350

400

450

500

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Flow

(cfs

)


Nueces River at Laguna OCR - Annual Flow Frequency Curve

Historical

Full BBEST

Modified BBEST W

Modified BBEST A

No E-Flow Criteria

Period of Record: 1/1/1934 to 12/31/1996Period of Record: 1/1/1934 to 12/31/1996Period of Record: 1/1/1934 to 12/31/1996Period of Record: 1/1/1934 to 12/31/1996

16

0

50

100

150

200

250

300

350

400

450

500

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Flow

(cfs

)


Nueces River at Laguna OCR - Annual Flow Frequency Curve

Historical

Full BBEST

Modified BBEST W

Modified BBEST A

CCEFN

Lyons

No E-Flow Criteria

Period of Record: 1/1/1934 to 12/31/1996Period of Record: 1/1/1934 to 12/31/1996Period of Record: 1/1/1934 to 12/31/1996Period of Record: 1/1/1934 to 12/31/1996

Nueces River @ Cotulla - BBEST

17


Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct


Overbank Events

High Flow Pulses

Base Flows (cfs)

38



Qp: 1,560 cfs with Average Frequency 2 per yearVolume Bound is 24,200Duration Bound is 28


Qp: 1,180 cfs with Average Frequency 1 per seasonVolume Bound is 17,200Duration Bound is 24


per seasonVolume Bound is

1,030Duration Bound is 16








Qp: 8 cfs with Average Frequency 2 per seasonVolume Bound is 100Duration Bound is 13






10 7 1531

1

1

426

Flow Levels

High (75th %ile)

Medium (50th %ile)

Low (25th %ile)

Subsistence

18

7% 9%15%

58%

18%

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

No E-Flow Criteria Lyons CCEFN Modified BBEST A Modified BBEST W Full BBEST

Firm

Yie

ld (a

cft/

yr)

Cotulla Reservoir - Firm Yield

19

0

50

100

150

200

250

300

350

400

450

500

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Flow

(cfs

)


Cotulla Reservoir - Annual Flow Frequency Curve

Historical

Full BBEST

Modified BBEST W

Modified BBEST A

No E-Flow Criteria


20

0

50

100

150

200

250

300

350

400

450

500

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Flow

(cfs

)


Cotulla Reservoir - Annual Flow Frequency Curve

Historical

Modified BBEST W

Full BBEST

Modified BBEST A

CCEFN

Lyons

No E-Flow Criteria


Nueces River @ Cotulla - BBEST

21


Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct


Overbank Events

High Flow Pulses

Base Flows (cfs)

38



Qp: 1,560 cfs with Average Frequency 2 per yearVolume Bound is 24,200Duration Bound is 28


Qp: 1,180 cfs with Average Frequency 1 per seasonVolume Bound is 17,200Duration Bound is 24

















10 7 1531

1

1

426

Flow Levels

High (75th %ile)

Medium (50th %ile)

Low (25th %ile)

Subsistence

22

19% 20% 25% 26%

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

No E-Flow Criteria CCEFN Lyons Modified BBEST A Full BBEST Modified BBEST W

Firm

Yie

ld (a

cft/

yr)

Cotulla Off-Channel Reservoir - Firm Yield

16%

23

0

50

100

150

200

250

300

350

400

450

500

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Flow

(cfs

)


Cotulla Off-Channel Reservoir - Annual Flow Frequency Curve

Historical

Modified BBEST W

Full BBEST

Modified BBEST A

No E-Flow Criteria


24

0

50

100

150

200

250

300

350

400

450

500

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Flow

(cfs

)


Cotulla Off-Channel Reservoir - Annual Flow Frequency Curve

Historical

Modified BBEST W

Full BBEST

Lyons

CCEFN

Modified BBEST

No E-Flow Criteria


Path Forward Additional Presentations

BBEST - Aquatic Habitat TWDB - Sediment Transport

BBASC Adopt an Instream Environmental Flow Standard Recommendation Modified BBEST

Overbank Exemption Pulse Exemption Rule Base Flow with 50% Rule

Wet Average

25

Nueces Bay and Delta Inflow Regime BBASC Direction

Utilize BBEST Volume Targets Modify Attainment Frequencies for Balance

Four Focused Scenarios BBEST Recommendation Agreed Order – Safe Yield No Pass Thru’s OCR Agreed Order Safe Yield

Results Yield vs. Bay Inflow vs. Salinity

26

Order Compared to BBEST Sys Stor.

%

Jan (acft)

Feb (acft)

Mar (acft)

Apr (acft)

May (acft)

Jun (acft)

Jul (acft)

Aug (acft)

Sep (acft)

Oct (acft)

Nov (acft)

Dec (acft)

Ann. (acft)

>70 2,500 2,500 3,500 3,500 25,500 25,500 6,500 6,500 28,500 20,000 9,000 4,500 138,000

70-40 2,500 2,500 3,500 3,500 23,500 23,000 4,500 5,000 11,500 9,000 4,000 4,500 97,000

40-30 1,200 1,200 1,200 1,200 1,200 1,200 1,200 1,200 1,200 1,200 1,200 1,200 14,400

>30 0 0 0 0 0 0 0 0 0 0 0 0 0

2001 TCEQ Agreed Order

Condition (Target Salinity)

Nueces Bay Freshwater Inflow Regime (Attainment) Recommendations

One overbanking event per year of 39,000 acft; maximum discharge of 3,600 cfs Annual Total (acft)

Attainment

High (10) 125,000 acft (20%) 250,000 acft (25%) 375,000 (20%) 750,000 25%

Base (18) 22,000 acft (60%) 88,000 acft (60%) 56,000 (75%) 166,000 80%

Subsistence (34) 5,000 acft (95%) 10,000 acft (95%) 15,000 acft (95%) 30,000 95%

Winter = Nov - Feb Spring = Mar - Jun Summer/Fall = Jul - Oct

2011 BBEST Recommendation

27

BBEST Recommendation for B&E Condition

(Target Salinity)


One overbanking event per year of 39,000 acft; maximum discharge of 3,600 cfs

Annual Total (acft)

High (10) 125,000 acft (20%)

250,000 acft (25%)

375,000 (20%)

750,000 (25%)

Base (18) 22,000 acft (60%)

88,000 acft (60%)

56,000 (75%)

166,000 (80%)

Sub. (34) 5,000 acft (95%)

10,000 acft (95%)

15,000 acft (95%)

30,000 (95%)

Winter = Nov - Feb

Spring = Mar - Jun

Summer/Fall = Jul - Oct

28

29

0

50,000

100,000

150,000

200,000

250,000

300,000

Full_BBEST Base_SY No_PT OCR_SY

Acft

/Yr

CCR/LCC/LT System Safe Yield (acft/yr)

SY (75K Min)

30

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

450,000

500,000

Full_BBEST Base_SY No_PT OCR_SY

Acft

/Yr

CCR/LCC/LT System Safe Yield - Average Annual Bay Inflow - Average Annual B&E Release

SY (75K Min)Avg AQBAYAvg ABEREL

31

0%

5%

10%

15%

20%

25%

30%

W-H Sp-H S-H A-H

BBESTBBEST SimulationBase SY (Order)No Pass ThroughsOCR-SY-Order

32

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

W-B Sp-B S-B A-B

BBEST RecommendationBBEST SimulationBase SY (Order)No Pass ThroughsOCR_SY_Order

33

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

W-S Sp-S S-S A-S

BBEST Recommendation

BBEST Simulation

Base SY (Order)

No Pass Throughs

OCR-SY-Order

34

0

5

10

15

20

25

30

35

40

45

50

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Salin

ty at

SALT

03

Percent of Time

BBEST Scenario SALT03 (ppt)Base Agreed Order SALT03 (ppt)No Pass Thru's SALT03 (ppt)OCR SY SALT03 (ppt)

35

0

5

10

15

20

25

30

60% 65% 70% 75% 80% 85% 90% 95% 100%

Salin

ty at

SALT

03

Percent of Time

BBEST Scenario SALT03 (ppt)Base Agreed Order SALT03 (ppt)No Pass Thru's SALT03 (ppt)OCR SY SALT03 (ppt)

13%

8% 5%

6%

B&E – Attainment Freq – Opt 1 Condition

(Target Salinity)


Annual Total (acft)

High (10) 125,000 acft (9%)

250,000 acft (10%)

375,000 (12%)

750,000 (11%)

Base (18) 22,000 acft (22%)

88,000 acft (19%)

56,000 (33%)

166,000 (38%)

Sub. (34) 5,000 acft (61%)

10,000 acft (82%)

15,000 acft (71%)

30,000 (90%)

Winter = Nov - Feb

Spring = Mar - Jun


36

B&E – Attainment Freq – Opt 2 Condition

(Target Salinity)


Annual Total (acft)

High (10) 125,000 acft (11%)

250,000 acft (11%)

375,000 (12%)

750,000 (16%)

Base (18) 22,000 acft (23%)

88,000 acft (30%)

56,000 (40%)

166,000 (47%)

Sub. (34) 5,000 acft (69%)

10,000 acft (88%)

15,000 acft (74%)

30,000 (95%)

Winter = Nov - Feb

Spring = Mar - Jun


37

For BBASC Consideration BBASC Adopt an Estuary & Delta Environmental Flow

Standard Recommendation BBEST Seasonal Volume Targets Attainment Frequencies

Option 1 - Agreed Order plus OCR Option 2 - Agreed Order

38

Path Forward / Questions? Report Compilation

39

Scenario Results Yield vs. Avg. Annual Bay Inflow

41

Run # Run Description SY (75K Min) Avg AQBAY1 Base_SY 204,449 379,2842 No_PT 235,001 350,8003 Seasonal_order 169,691 410,4544 Spring_target 170,889 415,4915 Summer_Tar 180,960 405,9006 Winter_Tar 213,264 372,5477 3K_All_months 230,089 358,0198 Reduced may June 220,110 364,423

42

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Mon

thly

Bay

Inflo

w (A

cft)

Percent of Time (% - months)

Monthly Bay Inflow - Frequency

Run 1

Run 2

Run 3

Run 4

Run 5

Run 6

Run 7

Run 8

presentation to nueces bbasc sam vaugh, pe cory shockley ......presentation to nueces bbasc . sam...

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