Update to the 1992 Dry Creek Watershed Flood Control Plan CESI/RBF RR/KM FEMA CTP HYDROLOGY.

Update to the 1992 Dry Creek Watershed Flood Control Plan

CESI/RBF

RR/KM

FEMA CTP HYDROLOGY

Purpose of the Plan Update• To develop updated hydrologic model that

can adequately evaluate the flood damage reduction potential of achievable projects,

• Asses the impact of the development that has occurred with realistic consideration of the effectiveness of local developer installed detention basins,

• Identify plausible multiple objective regional flood reduction and/or mitigation measures that could be expected to be met with broad support,

• Provide a list of local, cost effective, flood damage reduction projects, and

• Prepare a funding plan consistent with Plan Update project recommendations and current development projections


New Modeling• Major Revisions to the Previous (1992) Plan Model

– Watershed Boundary Changes

Finding Mitigation in the Urbanized Dry Creek Watershed


• Watershed Detail Substantially Increased. 170 watersheds became 1,250+ watersheds.



– HEC-HMS replaces HEC-1 for individual hydrograph development portion of modeling.• Integrated GIS functionality• Adds greater Flexibility in Future

– DRY CREEK TOOLBOX


Baseline Comparison1992 Estimated Imperviousness of the Watershed = 17.8%.

Dry Creek Watershed Imperviousness

1992


Baseline ComparisonCurrent Estimated Imperviousness of the Watershed = 22.0%.


Current


Baseline ComparisonFuture General Plan Build-out Estimated Imperviousness = 27.0%.


Future GP Build-out


Baseline ComparisonThe development area of the watershed has increased from 35,900 acres to 44,400 acres, and will increase to 58,700 acres at General Plan build-out.

Timeline Condition Acreage of Development

(acres)

Rural Residential Portion

(acres)

1992 35,900 9,000

Current 44,400 12,300

General Plan

Build-out

58,700 17,200


Historical Flooding in the Watershed

• Documented Recent Major Floods:Feb 1986 (50-100 yr)

Jan 1995 (200-yr)

Dec 1995 (2-yr)

Jan 1997 (10-yr)

Feb 1998 (10-yr)

Dec. 2005 (10-yr)



• JAN 1995 – 2-day event – 358 Structures Flooded within Roseville.– Rainfall Matched 200-year intensities for a 6-hour and 24-hour

storm event.– Between 3.9 inches and 7.6 inches of rain in Dry Creek Watershed– End of strong (5-year) El Nino/beginning of weak La Nina event



• What to Avoid!



Comparison of Pacific Pressure (El Nino effect)


1986 JAN

1997

JAN

1995

DEC

2005

DEC

1995

JAN

2010


– Hydraulic Routing Model as a Hydrologic Component (HEC-RAS)


AntelopeBlwClove

Ant

el

ope

C

ree

k

Reach 1

Above Linda

below Linda

Clover Valley1

Cl

ov

er

Va

lley

Above Cirby

Dr

y C

reek

Below Cirby

Dry Creek

Reach 1

Above S Branch

Lind

a

Creek

South Branch

Below S Branch

Linda

Cre

ek

Below Strap

Below SecretBet Secret-False

Above False

Mi ners

Ravine

Reach 1S

ec

ret R

a vine

Below Sucker

Reach 1

Reach 1

S uc

ker

RavineAnteClover

FalseMinersMR-SEC

SA-Secret

SamoaWay

US Hunt Dr

EndDryCk

Cirby-LindaCirby-DryCk

South Branch

Linda-Strap

4594 of the 4951 XS's are not Geo-Referenced ( Geo-Ref user entered XS Geo-Ref interpolated XS Non Geo-Ref user entered XS Non Geo-Ref interpolated XS)

8133.93*7956.93*

7734.34*7484.099

7298.0997131.099

6965.64*

6767.16*

6304.499

5814.83*

5720.16*5428.83*

5167.16*

4888.499

4767.4994533.16*

4354.4994259.16*

4163.83*

3987.24*

3824.74*

3357.9992752.59*2502.999

2464.5992455.599

2359.499

2349.4992180.899

1992.8991703.39*

1394.899855.899*

385.192.5*

0.

84214.40

84146.8*

84079.3*

83365.4*

83181.9083001.9*

82817.8*

Reach 1

740072006900.*

66006400

6000

57005400

52005000

48004600

44004290.*

4020

37003600.*

3300

3000.*

2800.*2500

230020851800

1500.*

1275.*950750426360

245

Fa

lse Ra

vin

e

Below Secret 3734.100

3689.81*3379.24*

2689.83*2353.83*

1745.3001446.400

1422.400

1290.400

1277.4001159.099

942.8999

874.95*

807.733.45*

592.499*394.349*

184.333*

111.0.

Mine rs Ravine

Bet Secret-False

7619.9006964.9*

6145.0005942.5*

5068.38*4605.100

4415.1*4175.76*

Miners Ravi ne

17696.7*17286.6*

17070.0*16828.6*

16548.9516408.83

16172.8915925.8*

15497.6*14993.7*

14601.78

14291.7*14146.17

13180.513028.30

12909.7012821.9*

12734.2*12646.4*

12558.70

12458.8*

12358.9*

12210.5*12162.1011862.1*

11562.1011300.8*

11178.3*

11117.10

11060.9*

11004.7*10892.3010644.8*9570.55*

9419.4*9143.2*

8870.77*8780.65*

8690.52*8600.400

8447.65*

8294.9

8146.56*

8047.67*7948.78*

6049.23*5613.0995328.099

5048.34*4537.76*3922.09*

3396.45*3313.2*3229.95*

3050.2*2857.2*

2594.03*2178.89*

1560.36*1408.89*

1255.6991114.69*

962.232*

798.3000621.633*443.7000

307.8*

216.714*130.428*

44.1428*1

FalseMiners

MR-SEC

EndDryCk

4594 of the 4951 XS's are not Geo-Referenced ( Geo-Ref user entered XS Geo-Ref interpolated XS Non Geo-Ref user entered XS Non Geo-Ref interpolated XS)

Dry Creek Watershed Study UpdateCalibration

Dry Creek Watershed Study UpdateTechnical Analysis Status

• Raw Precipitation Values published in SWMM


VERNON GAGE - DEC 25 2005 to JAN 13 2006

0100020003000400050006000700080009000

10000

DATE

Flo

w (cf

s) Calib HMS

Gage Measured

Cal RAS

VERNON GAGE - SMALL EARLY EVENT

0200400600800

100012001400160018002000

38711.54167 38712.54167

DATE

Flo

w (cf

s) Calib HMS

Gage Measured

Calib RAS

VERNON GAGE PEAK - DEC 31 2005

0

5000

10000

38711.54167 38712.54167

DATE

Flo

w (cf

s)Calib Predict Gage Measured

HEC-RAS

New Modeling• Major Revisions to

the Previous (1992) Plan Model– Storm Centering:

Analysis of all 1200+ storm centers and 4 different potential storm angles at each storm centering location, yielded 7 storm combinations that can control peak flows for the various locations in the watershed.

DRY CREEK TOOLBOX

Dry Creek Watershed Study UpdateTechnical Analysis Status

• Raw Precipitation Values published in SWMM

NOAA 14 AP 6 vs SWMM for Gage 1632

0

1

2

3

4

5

6

7

Time (minutes)

Pre

cip (in

)

NOAA 14 High

NOAA 14 Median

NOAA 14 Low

SWMM 100-year

1632-JAN 1995

1632-DEC 1995

1632-JAN 1997

1632-DEC 2005

NOAA 14 AP 6 vs SWMM for Gage 1632

0

2

4

6

8

10

12

14

16

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00

Time (days)

Pre

cip (in

)

NOAA 14 High

NOAA 14 Median

NOAA 14 Low

SWMM 100-year

1632-JAN 1995

1632-DEC 1995

1632-JAN 1997

1632-DEC 2005

Update to the 1992 Dry Creek Watershed Flood Control Plan CESI/RBF RR/KM FEMA CTP HYDROLOGY.

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Transcript of Update to the 1992 Dry Creek Watershed Flood Control Plan CESI/RBF RR/KM FEMA CTP HYDROLOGY.