CSOP MODEL EVALUATION AND RECOMMENDATIONS Revised on May 9, 2005 - - PowerPoint PPT Presentation

CSOP

MODEL EVALUATION AND RECOMMENDATIONS Revised on May 9, 2005

PURPOSE OF THE PRESENTATI ON

• REVI EW THE 2X2 MODEL RESULTS FOR THE EAST AND

WEST BOOKENDS, ALTERNATI VE 3 AND ALTERNATI VE 4.

• FOCUS: CHECK FOR POSSI BLE I MPACTS TO FLOOD LEVELS

OF SERVI CE (LOS) I N DEVELOPED AREAS (URBAN AND AGRI CULTURAL).

• DEVELOP RECOMENDATI ONS TO PREVENT LOSS OF FLOOD

LEVEL OF SERVI CE FOR ALTERNATI VE 5.

AVAI LABLE MODEL RESULTS

POSTED AT CSOPWEB – May 3, 2005

ALTERNATIVE 1 (EAST BOOKEND), ALTERNATIVE 2(WEST BOOKEND), ALTERNATIVE 3, ALTERNATIVE 4 AND ALTERNATIVE 7R5(EXISTING CONDITIONS)

• ANY MODEL I S LI MI TED BY THE QUALI TY OF THE

DATA AVAI LABLE AND ASSUMPTI ONS MADE.

• AS A RESULT ONLY A COMPARATI VE ANALYSI S WAS

CONDUCTED, BY EVALUATI NG EACH ALTERNATI VE PERFORMANCE AGAI NST ALTERNATI VE 7R5 (EXI STI NG CONDI TI ONS RUN).

• THI S COMPARATI VE PROCESS REDUCES THE I NFLUENCE

OF THE MODEL UNCERTAI NTI ES I N THE DECI SI ON MAKI NG PROCESS.

HOW GROUNDWATER LEVELS AFFECT DRAI NAGE PERFORMANCE

LOSS OF LEVEL OF SERVI CE

DRAINAGE SYSTEM

• TYPICAL DRAINAGE SYSTEM
• 3 TO 4 MILLION LINEAR FEET

OF DRAINAGE NETWORK CANNOT BE RETROFITTED

GROUND LEVEL

GROUNDWATER LEVELS

WCA-3B

SERENA LAKES & COUNTRY WALK BELEN & SWEETWATER

TARGET AREAS OF EVALUATI ON

2326

S-335 G-211 S-331 WATER LEVELS I N WCA-3B AFFECT WATER LEVELS I N URBANI ZED AREAS

BELEN, SWEETWATER, SERENA LAKES & COUNTRY WALK – FLOOD PRONE AREAS

STAGES ON WCA-3B – DEPTH 2.5 FEET

4% ALT7R5 17% ALT3 & 4 35% ALT2 (WBE) 8% ALT1(EBE) PERFORMANCE MEASURE TARGET ELEVATI ON HI GHER % ABOVE TARGET ELEVATI ON MEANS LONGER HI GH STAGE DURATI ON, MORE SEEPAGE AND NEGATI VE I MPACT ON THE ENVI RONMENT AND FLOODI NG

RI SE ON L-31N CANAL STAGES - ALTERNATI VE 4 – S-331

ALT 4 MEAN STAGE~ 5.2 EXI STI NG CONDI TI ONS MEAN STAGE~ 4.2 RI SE OF 1 FOOT ON MEAN CANAL LEVELS CAUSES RI SE ON WATER TABLE TO THE EAST

SERENA AREA AND COUNTRY WALK 2X2 RESULTS WATER TABLE STAGE DI FFERENCE

ALTERNATI VE 4 – ALT 7R5

RI SE OF 1 FOOT ON CANAL LEVELS CAUSES RI SE ON GROUNDWATER TO THE EAST OF L-31N-> NEED TO CONTROL SEEPAGE

Files:depth.alt4.roco;depth.alt7r5.roco

SERENA & COUNTRY WALK L-31N I N THE SERENA & COUNTRY WALK AREA, THERE I S A TENDENCY FOR I NCREASE OF GROUNDWATER LEVELS WHEN COMPARED TO ALT7R5 (“EXI STI NG CONDI TI ONS”) NOTE ON LEGEND: POSI TI VE NUMBERS MEAN I NCREASE ON WATER LEVELS WHEN COMPARED TO MODELED EXI STI NG CONDI TI ONS (ALT7R5)

ALTERNATI VE 4 - CONCLUSI ONS

• I N URBAN AREAS (SERENA LAKES AND COUNTRY WALK) GROUNDWATER LEVELS

I NCREASE APPROXI MATELY 2 I NCHES WHEN COMPARED TO ALTERNATI VE 7R5 (“EXI STI NG CONDI TI ONS”).

• MODEL OUTPUT I NDI CATES POTENTI AL FOR HI GHER GROUNDWATER LEVELS EAST

OF THE L-30, L-31N AND L-31W CANALS. THERFORE THI S ALTERNATI VE I S SLI GHTLY WORSE I N TERMS OF FLOODI NG THAN ALTERNATI VE 3, WORSE THAN EAST BOOKEND (ALTERNATI VE 1) BUT I S AN I MPROVEMENT WHEN COMPARED TO WEST BOOKEND (ALTERNATI VE 2).

• A 1-FOOT RI SE ON THE CANAL LEVELS ON THE L-31N CANAL BETWEEN G-211 AND

S-331, WHEN COMPARED TO EXI STI NG CONDI TI ONS (ALT7R5), CAN RESULT I N FLOODI NG TO THE EAST, DUE TO SEEPAGE RESULTI NG I N HI GHER GROUNDWATER STAGES.

• MODEL RUNS I NDI CATE THAT UNACCEPTABLE HI GH WATER LEVELS OCCUR 17% OF

THE TI ME I N THE WCA 3B, I N THE VI CI NI TY OF THE L-30N CANAL; UNDER ALT7R5 (EXI STI NG CONDI TI ONS) THOSE LEVELS OCCUR 4% OF THE TI ME.

ALTERNATI VE 5 – WI SH LI ST FOR MODELI NG

• ADEQUATE CONVEYANCE CAPACI TY UNDER TAMI AMI

TRAI L TO I NCLUDE EVALUATI ON TO I NCREASE S-356 PUMP STATI ON CAPACI TY, TO REDUCE HI GH STAGES I N WCA-3B

• CONTROL FOR SEEPAGE I S NEEDED TO PREVENT LOSS OF

LEVEL OF SERVI CE TO THE EAST, FROM S-335 TO S-331, PERHAPS I NCLUDI NG MODI FI CATI ON OF S-331’S OPERATI ONAL CRI TERI A TO AVOI D HI GH STAGES I N THE L-31 CANAL

• PASSI VE CONTROL STRUCTURES ARE NEEDED ON L-67

CANAL TO AVOI D EXTREME HI GH STAGES I N WCA-3B

• NO FLOOD I MPACTS TO URBAN/ AGRI CULTURAL AREAS

CLOSI NG STATEMENT

DUE TO MODEL LI MI TATI ONS AND THE POTENTI AL FOR FLOOD I MPACTS, MI AMI - DADE DERM REQUESTS THAT THE CSOP STRUCTURES BE PLACED I N OPERATI ON AFTER DETERMI NATI ON OF OPTI MUM STAGES, BASED ON FI ELD TESTS, TO MAXI MI ZE BENEFI TS FOR THE ENP WI THOUT I MPACTS TO FLOOD LEVELS OF SERVI CE I N URBAN AREAS