Appendix 1: Waterway crossings - Home | NZ … - 5-C1814.00 Peka Peka to North Otaki 440PN Element -...

Peka Peka to North Ōtaki Expressway: Assessment of Stormwater Effects

5-C1814.00

February 2013

Appendix 1: Waterway crossings

Includes:

1. Catchment Map of the small and medium Waterway crossings – Drawing Sheet DR09

2. KCDC SCS method inputs to HEC HMS model

3. KCDC SCS method outputs from HEC HMS model

4. Comparison of results between SCS method and regional method.

PEKA PEKA

TE HORO BEACH

TE HORO

OTAKI BEACH

OTAKI

O

T

A

K

I

R

I

V

E

R

WA

IT

OH

U S

TR

EA

M

M

A

N

G

A

O

N

E

S

T

R

E

A

M

HA

DF

IE

LD

R

D.

B

E

A

C

H

R

D

.

O

T

A

K

I

G

O

R

G

E

R

D

.

R

A

H

U

I

R

D

.

CHAINAGE 0 ON NEW

ROAD ALIGNMENT

HADFIELD CATCHMENT

131ha.

KUMOTOTO CATCHMENT

64.3ha.

AWATEA CATCHMENT

223ha.

CORDING CATCHMENT

11.8ha.

CAVALLO CATCHMENT

20.8ha.

JEWELL CATCHMENT

360ha.

AVATAR CATCHMENT

65.7ha.

COOLEN CATCHMENT

6.5ha.

SETTLEMENT HEIGHTS

CATCHMENT 308ha.

GEAR CATCHMENT

176ha.

MANGAONE CATCHMENT

OTAKI CATCHMENT BRIDGE

OVER RIVER AT CH. 3650

RACECOURSE CATCHMENT

17.1ha.

TE MANUAO CATCHMENT

31.6ha.

GREENWOOD CATCHMENT

162ha.

WAITOHU CATCHMENT

1:200000 500 1000 2000 mat A1

200

100

5010

0mm

300

mm

ScaleProject No. Drawing No. Sheet. No.

Project

Sheet

Revision

Original Sheet Size A1 [841x594] Plot Date

Drawn Approved Revision DateDesigned

NEW ZEALAND TRANSPORT AGENCYPEKA PEKA TO NORTH OTAKI EXPRESSWAYFOR CONSENTING

Preliminary Design - Water EngineeringCatchment Area Plan to Proposed Road Alignment

5/2664/1/6504 DR09 R05-C1814.00 1:20000 at A109/08/12 @ 13:56 p:\projects\5-c1814.00 peka peka to north otaki 440pn\900 drawings\910 cad\stormwater (.32) concept plans\design updates march2011\5_2664_1_6504_dr9_r0.dwg

G.D. T. Coulman May 2012R.C.

Approved Revision DateRevision Amendment

1500

CHAINAGE 12212 ON NEW ROAD

ALIGNMENT. END OF CONTRACT

TE ROTO CATCHMENT

11.6ha.

ANDREWS CATCHMENTS 2.8 &

1.3ha.

MANGAPOURI CATCHMENT

236.6ha.

SCHOOL CATCHMENT

175ha.

NOTES:

1. CONTOUR INTERVAL IS 20m

LEGEND:

EXISTING ROADS

STREAMS/DRAINAGE DITCHES

Existing SH1

PROPOSED EXPRESSWAY

ALIGNMENT

Project - 5-C1814.00 Peka Peka to North Otaki 440PN

Element - Stomwater - waterway culvert - inputs to HEC-HMS for flow assessment

Printed 1/08/2012

Page 1 of 15

Summary table - inputs to HEC-HMS for flow assessment

Culvert

location

Culvert

catchment

area (Km2)

Initial

abstraction

(mm)

Curve

number (CN)

Connected

Impervious

Areas (%)

Time of

Concentration

(hours)

Storage Ratios (R)Q100 24hr

depth (mm)

Ch 0+394 1.620 5.00 82 0% 1.08 0.78 175

Ch 0+825

Ch 0+935

± Ch1+650 0.316 1.50 84.3 0% 0.58 0.43 155

Ch1+940 2.366 4.00 81 8% 1.07 1.14 175

Ch 2+195 0.171 5.00 78 0% 0.25 0.37 155

Ch 2+620 0.116 5.00 78 0% 0.35 0.53 155

Ch 2+880 0.028 5.00 78 0% 0.15 0.22 155

Ch 3+020 0.013 5.00 78 0% 0.11 0.17 155

Ch 6+600

Ch 7+250

& 7+430

-

Ch 8+610 1.760 5.00 82 0% 1.19 1.45 175

Ch 8+910 3.080 5.00 80 0% 1.03 1.14 175

Ch 8+980 0.065 5.00 82 0% 0.21 0.26 165

Ch 9+370 0.657 5.00 82 0% 0.57 0.70 165

- 5.562 5.00 81 0% 0.97 1.19 175

Ch 10+020 3.600 5.00 80 0% 1.27 1.41 175

Ch 10+590 0.208 5.00 82 0% 0.35 0.52 165

Ch 10+930 0.118 5.00 82 0% 0.27 0.40 165

Ch 11+335 2.230 5.00 80 0% 1.34 1.34 175

Ch 11+630 0.643 5.00 80 0% 0.49 0.40 170

Assessment components for HEC-HMS imputs are listed below:

- 24 hour rain fall depth

- Initial abstraction

- Normalised Depth-Duration Relationship

- Soil types and Curve Numbers

- Connected Impervious area

- Storage Value (R)

- Time of Concentration

Other information used

-

- Geotec info - Preliminary soil type maps, GWRC test pit locations and GWRC test pit logs

Flows assessed by other means





Catchment map showing catchment name, aproximate culvert location and culvert catchment area

This is an assessment of inputs for peak flow calculations using HEC HMS, as detailed in SKM's

'Isohyet Based Calculation of Design Peakflows' in appendix 1 of KCDC 's Subdivision and

development principles and requirements 2005 (including the August 2008 updated rainfall analysis)

Jewell

Cavallo

Cording

Te Roto

Andrews 1

Andrews 2

Otaki

Mangaone

Gear

Settlement Heights

Coolen

Catchment name

Greenwood

Waitohu

Te Manuoa

Mangapouri

Racecourse

Gear to Jewell

combined

Avatar

Awatea

Kumototo

Waitohu tributary

School

\\wesv01\branchlib\projects\5-C1814.00 Peka Peka to North Otaki 440PN\500 Technical\530 Stormwater\530.43 -

prelim\03 - Workings and drafts\03 - Culvert Flows\01 - HEC inputs table 2012 07 19.xlsx



Printed 1/08/2012

Page 2 of 15

24 hour rain fall depth

Q100 + CC to 2090

Q10 + CC to 2090

2090 Climate Affected Isohyet Maps (from Appendix B of SKM's Update of Kapiti Coast Hydrometric Analysis -

Which is an update of Appendix A, of Appendix 1, of KCDC 's Subdivision requirements 2005)





Printed 1/08/2012

Page 3 of 15

Q2 + CC to 2090





Printed 1/08/2012

Page 4 of 15

From 2090 Climate Affected Isohyet Maps: Normalised Depth-Duration Relationship

Duration

5 Mins 12 12 9 8 6 5

15 Mins 22 21 15 14 10 8

1 Hour 40 39 28 26 18 16

2 Hour 54 53 37 35 25 21

3 Hour 71 69 49 46 32 28

6 Hour 93 90 64 60 42 36

12 Hour 126 122 87 81 57 49

24 Hour 155 150 107 100 70 60

Duration

5 Mins 13 14 9 9 6 6

15 Mins 23 24 16 15 11 10

1 Hour 43 44 30 29 20 18

2 Hour 58 60 40 39 26 25

3 Hour 76 78 53 51 35 32

6 Hour 99 102 69 66 45 42

12 Hour 134 138 93 89 61 57

24 Hour 165 170 115 110 75 70

Duration

5 Mins 14 14 10 10 7 6

15 Mins 25 25 18 17 12 11

1 Hour 47 46 33 31 22 21

2 Hour 63 61 44 42 30 28

3 Hour 83 81 58 55 39 37

6 Hour 108 105 75 72 51 48

12 Hour 146 142 101 97 69 65

24 Hour 180 175 125 120 85 80

Duration

5 Mins 16 15 12 12 7 5

15 Mins 28 27 21 20 13 8

1 Hour 52 49 39 38 23 16

2 Hour 70 67 53 51 32 21

3 Hour 92 87 69 67 41 28

6 Hour 120 114 90 87 54 36

12 Hour 162 154 122 117 73 49

24 Hour 200 190 150 145 90 60

Normalised Q100 Rainfall depth




0.81

1.00

0.46

0.35

0.46

0.08

0.14

0.81

1.00

0.35

0.46

0.08

0.14

0.81

1.00

0.35

0.46

0.08

0.14

0.81

1.00

As the road and catchments are an area rather than a single point, the rainfall value veries over the area. So we

have given 4 rain fall values (not to be used for the Waitohu, otaki or Mangaone)

Normalised

Rainfall Depth

(I/I24)0.08

0.14

0.35

0.26

0.60

Normalised

Rainfall Depth

(I/I24)

0.26

0.60

Normalised

Rainfall Depth

(I/I24)

0.26

0.60

Normalised

Rainfall Depth

(I/I24)

0.26

0.60





Printed 1/08/2012

Page 5 of 15

Depth-Duration Relationship - converted to intencity

Duration

(h)

0.083333

0.25

0.5

1

2

3

6

12

24

Duration

(h)

0.083333

0.25

0.5

1

2

3

6

12

24

Duration

(h)

0.083333

0.25

0.5

1

2

3

6

12

24

Duration

(h)

0.083333

0.25

0.5

1

2

3

6

12

24

32 22 15

17

33 22

28 19 13

11

7

12

8 5

5 3

8

70 48

47

68 47 31

64 44 29

74 51 35

24

92

43

29

173 120 82

101

18

Q10 Rainfall (Southern

catchments) intencity

(mm/h)

4

82 62 37

86

rainfall Intencity

25

64

30

20

18

42

20

13

12

112 84 50

52 39

20

14 10 6

23 14

144

15 9

13 9

12 8 6

8 5

Q100 Rainfall (North half

of road) intencity (mm/h)

Q100 Rainfall (South half

of road) intencity (mm/h)

Q100 Rainfall (Northern


(mm/h)



(mm/h)

Q10 Rainfall (North half of

road) intencity (mm/h)

Q10 Rainfall (South half of

road) intencity (mm/h)



(mm/h)

8 6 4

10

6

103

60

28

31

19

16

11

7

4

87

40

27

23

35 26 16

192

67

39

18

Q2 Rainfall (North half of road)

intencity (mm/h)

Q2 Rainfall (South half of road)

intencity (mm/h)


catchments) intencity (mm/h)


catchments) intencity (mm/h)

149

12

11

7

5

3

158 110 72

16

Interpelate





Printed 1/08/2012

Page 6 of 15

Initial abstractionFrom seciton 2.2.2.1 (Appendix 1 of KCDC Subdivision guide)

Extract from Appendix 1 of KCDC Subdivision guide - page 8

Culvert

Location

Rural or

Urban

Initial

abstraction

(mm)

Ch 0+394 Rural 5.00

Ch 0+825 Rural 5.00 Flows assessed by other means


± Ch1+65070% Urban,

30% Rural1.50

Ch1+94020% Urban,

80% Rural4.00

Ch 2+195 Rural 5.00

Ch 2+620 Rural 5.00

Ch 2+880 Rural 5.00

Ch 3+020 Rural 5.00


Ch 7+250

& 7+430Rural 5.00


- Rural 5.00Flows assessed by other means

Ch 8+610 Rural 5.00

Ch 8+910 Rural 5.00

Ch 8+980 Rural 5.00

Ch 9+370 Rural 5.00

- Rural 5.00

Ch 10+020 Rural 5.00

Ch 10+590 Rural 5.00

Ch 10+930 Rural 5.00

Ch 11+335 Rural 5.00

Ch 11+630 Rural 5.00

Gear to Jewell

combined

Avatar

Jewell

Cavallo

Cording

Mangaone

Gear

Settlement Heights

Coolen

Otaki

Flows assessed by other means (NB: strictly this catchment should

be split into 2 sub catchments however this is not nessesary as this

catchment is beign assessed by other means)

Catchment name

Greenwood

Waitohu

Te Manuoa

Mangapouri

Racecourse

Awatea

Kumototo

Te Roto

Andrews 1

Andrews 2

School

Waitohu tributary





Printed 1/08/2012

Page 7 of 15

Soil types and Curve Numbers (CN)

Soil group and curve numbert table

Soil GroupCurve

number

Soil Group D -

(due to Clay)82

-

-

Soil Group D -

(due to Clay)84

Soil Group D -

(due to Clay)81

Soil Group D -

(due to Clay)78

Soil Group D -

(due to Clay)78

Soil Group D -

(due to Clay)78

Soil Group D -

(due to Clay)

78

-

-

-

Soil Group D -

(due to Clay)82

Soil Group D -

(due to Clay

and Peat)

80

Soil Group D 82

Soil Group D -

(due to Clay

and Peat)

82

Soil Group D -

(due to Clay

and Peat)

81

Soil Group D -

(due to Clay

and Peat)

80

Soil Group D 82

Soil Group D 82

Soil Group D 80

Soil Group D 80

Gear to Jewell

combinedas above 4 catchments as above 4 catchments

See Project preliminary geology map and GWRC bore logs and refer to soil class descriptions and Curve Number

Delineation Tables located in page 9 and appendix B (of Appendix 1) of KCDC 's Subdivision and development

principles and requirements 2005

Recent Alluvium - highly veriable (Logs

S25/5310, S25/5319/1 are clay,

S25/5319/2, S25/5311 are sand/gravel)


Description of soils from geology map

and logs

as Racecourse

as Racecourse

Terrace Alluvion (log S25/5391 - Gravel and

clay)

Awatea

Kumototo

Terrace Alluvion (logs R25/5114, R25/5116,

R25/5118, Gravel/Clay)


Table 2-2a - Residential districts by average lot size: 2

acres (rural lots about 1.3ha)

Cover type

Recent Alluvium - highly veriable (Logs

S25/5285 is gravel,S25/5283, S25/5287,

S25/5295, S25/5300 are clay/gravel)

as Racecourse

Fan Deposits - highly veriable (no relevent

Logs, assuming some clay)


acres (Potential rural lots)



Fan Deposits - highly veriable (Logs

R25/5111(1/2), Gravel/Clay/Peat)





Half Table 2-2c Brush-brush-weed-grass mixture (77),

Half Table 2-2a - Residential districts by average lot

size: 2 acres (82) potential




Catchmet name

Greenwood

Waitohu



Te Manuoa

Gear

Settlement

Heights

Coolen

Terrace Alluvion (logs R25/5156(1/2/3),

R25/5266, R25/54045 Gravel/Clay/Peat)

as Settlemant heights

Fan Deposits - highly veriable (Logs

R25/5108(1/2), R25/5106, R25/5104,

Clay/Peat)



Avatar

Jewell

Cavallo

Cording




Waitohu

tributary

Mangapouri

Racecourse

Te Roto

Andrews 1

70% - Table 2-2a - Residential districts by average lot

size: 1/4 acre (sample 1, 28 lots in 2.2ha = 800m2)

(sample 2, 41 lots in 2.7ha = 650m2) (87)

30% - Table 2-2c - Meadow-continuous grass, Fair (78)

Table 2-2c - Meadow-continuous grass, protected from

grazing and generally mowed for hay - FairTable 2-2c - Meadow-continuous grass, protected from

grazing and generally mowed for hay - Fair

Terrace Alluvion (log S25/5297, 5391 -

Gravel and clay and 1m top soil)

School Flows assessed by other means


acres (large lots)








Andrews 2

Otaki

Mangaone

1/3 - Table 2-2a - Residential districts by average lot

size: 1/4 acre (as Te Manuoa) (87)

2/3 Table 2-2c - Meadow-continuous grass, Fair (78)









Printed 1/08/2012

Page 8 of 15

Extracts from Appendix 1 of KCDC 's Subdivision and development principles and requirements 2005 (page 9

& 10)





Printed 1/08/2012

Page 9 of 15

Connected Impervious area

Connected Impervious area summary table

Catchment name Culvert location

Extract from Appendix 1 of KCDC 's Subdivision and development principles and requirements 2005 (page 9 & 10)

Connected Impervious area

(as a % of total area)

Greenwood Ch 0+394

0.0%

0.0%

0.0%

Andrews 2 Ch 3+020

0.0%

0.0%

0.0%

7.8%

0.0%

0.0%

0.0%

0.0%

Racecourse Ch 2+195

Te Roto Ch 2+620

Andrews 1 Ch 2+880

Otaki

Mangaone

Gear

Cavallo

Cording

Awatea

Waitohu Ch 0+825

Te Manuoa ± Ch1+650

Mangapouri Ch1+940

Ch 6+600

Ch 7+250 & 7+430

Ch 8+610

0.0%

0.0%

0.0%

Gear to Jewell

combined - 0.0%

Coolen

Avatar

Jewell

Ch 8+910

Ch 8+980

Ch 9+370

Kumototo

Ch 11+335

Ch 11+630

Ch 10+020

Ch 10+590

Ch 10+930

0.0%

0.0%

0.0%

0.0%

0.0%

Settlement Heights

input from

individual calcs

below

See note below





Printed 1/08/2012

Page 10 of 15

Te Manuao Catchment

Land use type

Mangapouri Catchment

Land use type

0

Area (ha)

0

Residential A

Residential B

Residential C

Connected Impervious areas - individual catchment assessment

0.00%

0 0.0%

0.00%

0.00%

0.00%

0.00%

26.3%

0

0

0

10.3

0.0%

0.0%

31.600

From KCDC stormwater pipe network maps (from the KCDC GIS) these are the only 2 catchment with conencted

inpervious areas. Images of these are below.

Impervious % (from

extract above)

38%

55%

65%

4.1%

Impervious % of total area% of total Area

24.05%

2.26%

0.00%

0.00%

0.00%

0.00%

20

1.3

0.0%

0.0%

0.0%

0.0%

% of total Area Impervious % of total area

65% 0 0.0% 0.00%

100.0%

72%

0%

5.17%

6.9% 2.63%

Town Center 50% 0.00%

Road Designation 36% 0 0.0% 0.00%

Residential B 55% 19 9.4%

0.00%

Industrial 72% 0 0.0% 0.00%

Residential C

85% 0 0.0%

7.8%

Open space/rural 0% 169 83.7% 0.00%

Hospital 72% 0 0.0% 0.00%

Total 202.000 100.0%

Commercial

educational 72% 0 0.0%

Industrial

Commercial 0

63.3%

Road Designation

Town Center

educational

Hospital

Open space/rural

Total

0.0%

32.6%

72%

Residential A 38% 14

Impervious % (from

extract above) Area (ha)

0

72%

85%

36%

50%

NB: Although Te Manuoa catchment has some reticulation, it is

too small to be significant and the majority of the stormflows

will be above ground (300l/s in pipe v Q100 flow greater than

3000l/s). As such all flow is assumed to be overland flow, and a





Printed 1/08/2012

Page 11 of 15

The only area, on this project, with relevent connected Impervious areas is at the north end as shown here.

There are no connected Impervious areas south of the Otaki racing grounds

Otaki racing grounds

Otaki River

Otaki racing grounds

connected Impervious areas





Printed 1/08/2012

Page 12 of 15

Storage Value (R)

From seciton 2.2.3.3 (Appendix 1 of KCDC Subdivision guide)

R = Tc*Ratio/(1-Ratio)

Extract from Appendix 1 of KCDC Subdivision guide - page 11

Storage ratio table

Culvert

LocationRatio Tc(hours) R

Ch 0+394 0.42 1.08 0.78

Ch 0+825 Flows assessed by other means


± Ch1+650 0.43 0.58 0.43

Ch1+940 0.52 1.07 1.14

Ch 2+195 0.60 0.25 0.37

Ch 2+620 0.60 0.35 0.53

Ch 2+880 0.60 0.15 0.22

Ch 3+020 0.60 0.11 0.17


Ch 7+250

& 7+430Flows assessed by other means

- 0.55 1.42 1.73

Ch 8+610 0.55 1.19 1.45

Ch 8+910 0.53 1.03 1.14

Ch 8+980 0.55 0.21 0.26

Ch 9+370 0.55 0.57 0.70

- 0.55 0.97 1.19

Ch 10+020 0.53 1.27 1.41

Ch 10+590 0.60 0.35 0.52

Ch 10+930 0.60 0.27 0.40

Ch 11+335 0.50 1.34 1.34

Ch 11+630 0.45 0.49 0.40

1/3 flat lands 2/3 steepland

Rural steepland

Comment

1/5 steepland 3/5 high

storage residential 1/5

flatland

30% flat lands 70% high

storage residential

flat lands

flat lands

flat lands

flat lands



1/5 high storage residential

4/5 flatland

Mangapouri

Racecourse

Te Roto

Andrews 1

Andrews 2

Otaki

Mangaone

Awatea

Catchment name

Greenwood

Waitohu

Kumototo

Te Manuoa

Gear

Settlement Heights


Waitohu tributary

1/5 high storage residential

4/5 flatland


flat lands

flat lands

Gear to Jewell

combined 2/3 flat lands 1/3 steepland

2/3 flat lands 1/3 high

storage residential

Coolen

Avatar

Jewell

Cavallo

Cording

School





Printed 1/08/2012

Page 13 of 15

Time of Concentration (tc)From seciton 6.4 (Appendix 1 of KCDC Subdivision guide)

Extracts from Appendix 1 of KCDC Subdivision guide

Summary table of Time of concentratoin

Culvert

Location

overland

flow

(minutes)

pipe flow

(minutes)tc (minutes)

Ch 0+394 0 65

Ch 0+825 - -

Ch 0+935 - -

± Ch1+650 0 35

Ch1+940 0 64

Ch 2+195 0 15

Ch 2+620 0 21

Ch 2+880 0 9

Ch 3+020 0 7

Ch 6+600 - -

Ch 7+250

& 7+430- -

- 0 85

Ch 8+610 0 71

Ch 8+910 0 62

Ch 8+980 0 13

Ch 9+370 0 34

- 0 58

Ch 10+020 0 76

Ch 10+590 0 21

Ch 10+930 0 16

Ch 11+335 0 80

Ch 11+630 0 30

NB: Overland flow + open channel flow time selected from below.

Gear to Jewell combined 58 0

-

0

0

0

0

Racecourse

Te Roto

Andrews 1

0

-

-

21

9

7



0

0

0

0

open channel flow

(minutes)

kerb and channel flow

(minutes)Catchemnt name

0Greenwood

Waitohu

School 85 0

Te Manuoa

Mangapouri

0

Flows assessed by other means (DHI

medeling and flow measurments)

35

64

15

65

Waitohu tributaryFlows assessed by other means (DHI

medeling and flow measurments)-

71

62

13

34

76

21

Andrews 2

Otaki

80

Mangaone

30

Gear

Settlement Heights

Coolen

Avatar

Jewell

Cavallo

Cording

Awatea

Kumototo

0

0

0

0

0

16

NB: Although Te Manuoa catchment has some reticulation, it is

too small to be significant and the majority of the stormflows

will be above ground (200l/s in pipe v a total flow greater than

3000l/s). As such all flow is assumed to be overland flow.





Printed 1/08/2012

Page 14 of 15

Time of concentratoin Table (verious methods)

89 29

25

Gear to Jewell

combined64 24 58 25

Avatar 38 16

Cording 18 7

Jewell 84

Awatea

Coolen 14 7 13 7

34 17

80 30

Kumototo 33 11 30 11

28 76 30

Cavallo 23 9 21

Gear 79 30 71 32

tc =

58 L / (A0.1

Se0.2

)

tc =

3.98 L0.77

(Se-0.385

)

Te Manuoa

Mangapouri

Racecourse 16 10

8 5 7 5

Otaki -

11

20

3671

Greenwood

Waitohu

65

Catchemnt name tc =

56.868 (L3 / H)

0.385

Settlement Heights 68 24 62

27

-

Te Roto 23 16 21 17

Andrews 1 10 7 9 7

15

38 20 35

71 26

- -

10

16 7

Andrews 2

Mangaone

Flows assessed by other means -Waitohu tributary

-

Standard Method for

Rural Catchments

(minutes)

Ramser-Kirpich Method

(minutes)

Bransby-Williams Method

(minutes)

-

-Flows assessed by other means



34 64

US Soil Conservation Service

Method (minutes)

School 94 43 85 45

KCDC Preferred method





Printed 1/08/2012

Page 15 of 15

Catchment perameters table (for ToC)

Culvert

LocationLength (Km) Area (km

2) Slope

(m/km)

Top Lvl (m)

(at 90% of

catchment

lenth)

Top Lvl (m)

(top of

catchment)

Bottom Lvl (m) Comments

Ch 0+394 3.00 1.620 67.4 205 245 23 -



± Ch1+650 1.04 0.316 17.1 45 69 29 -

Ch1+940 2.50 2.366 23.6 65 90 12 -

Ch 2+195 0.40 0.171 13.6 17 18 12 -

Ch 2+620 0.45 0.116 5.2 16 17 14 -

Ch 2+880 0.18 0.028 8.6 15 16 14 Soakage

Ch 3+020 0.13 0.013 8.5 15 15 14 Soakage


Ch 7+250

& 7+430Flows assessed by other means

- 3.12 1.750 20.3 75 300 18under link

rd only

Ch 8+610 3.15 1.760 50.9 160 290 16 -

Ch 8+910 3.35 3.080 108.1 340 440 14 -

Ch 8+980 0.37 0.065 34.8 26 26 15 -

Ch 9+370 1.35 0.657 46.1 73 90 17 -

- 3.35 5.562 108.1 340 440 14downstream

conditions

Ch 10+020 4.20 3.600 107.4 425 545 19 -

Ch 10+590 0.78 0.208 64.1 60 68 15 -

Ch 10+930 0.60 0.118 82.2 60 68 16 -

Ch 11+335 4.20 2.230 105.5 415 585 16 -

Ch 11+630 1.50 0.643 166.7 240 364 15 -

NB:

- Length is measured along main channel

- For slope, Top Level is taken from 90% of the main channel length

- Slope is based on using 90% of the main channel length

Gear to Jewell

combined

Racecourse

Catchemnt name

Greenwood

Waitohu

Te Manuoa

Mangapouri

Cording

Awatea

Kumototo

Andrews 2

Otaki

Mangaone

Gear

Settlement Heights

Coolen

Avatar

Jewell

Cavallo

Te Roto

Andrews 1

School

Waitohu tributary




Element - Stomwater - culvert flows - Outputs from HEC-HMS

Printed 1/08/2012

Page 1 of 18

Summary of flows (inc. climit change to 2090)

Culvert location Q10 Peak flow (m3/s)Q100 Peak flow

(m3/s)Ch 0+394 8.6 13.3



± Ch1+650 2.0 3.2

Ch1+940 Flows assessed by other means

Ch 2+195 1.1 1.8

Ch 2+620 0.6 1.0

Ch 2+880 0.2 0.4

Ch 3+020 0.1 0.2


Ch 7+250 & 7+430 Flows assessed by other means

- Flows assessed by other means

Ch 8+610 6.6 11.0

Ch 8+910 12.5 21.1

Ch 8+980 0.6 0.9

Ch 9+370 3.5 5.7

Ch 10+020 17.7 21.8

Ch 10+590 1.3 2.2

Ch 10+930 0.9 1.4

Ch 11+335 8.2 13.7

Ch 11+630 4.0 6.4

The following pages capture the output graphs generated in HEC-HMS.

Cavallo

Cording

Awatea

Kumototo

Mangaone

Gear

Settlement Heights

Coolen

Avatar

Jewell

School

This is s summary of the outputs from HEC-HMS following the SCS method for flow

assessment, as detailed in SKM's 'Isohyet Based Calculation of Design Peakflows' in

appendix 1 of KCDC 's Subdivision and development principles and requirements 2005

(including the August 2008 updated rainfall analysis)

Waitohu tributary

Otaki

Summary table - Outputs from HEC-HMS for culvert flows,

(Climate change inclusive to 2090 using mean MfE guidance)

Catchmet name

Greenwood

Waitohu

Te Manuoa

Mangapouri

Racecourse

Te Roto

Andrews 1

Andrews 2

\\wesv01\branchlib\projects\5-C1814.00 Peka Peka to North Otaki 440PN\500 Technical\530

Stormwater\530.43 - prelim\03 - Workings and drafts\03 - Culvert Flows\03 - HEC outputs 2012 07 19.xlsx



Printed 1/08/2012

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Greenwood





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Racecource





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Te Manuao





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Mangapouri (For comparison of hydrological methods only)





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Te Roto





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Andrews A (or 1)





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Andrews B (or 2)





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Gear





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Settlement Heights





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Coolen





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Avatar





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Gear to Avatar combined





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Jewell





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Cavallo





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Cording





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Awatea





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Kumototo



Coolen Te Roto Cording Racecourse

Cavallo Te Manuao

Kumototo Avatar

Greenwood

Gear

Awatea

Mangapouri

Settlement Heights Jewell

0

5

10

15

20

25

0.0 0.5 1.0 1.5 2.0 2.5 3.0

1%

AEP

flo

w (

m3

/s)

Area^0.8 (km2)

HEC-HMS model predictions

scaled Mangaone at Ratanui

Linear (HEC-HMS model predictions)

Appendix 1: Waterway crossings - Home | NZ … - 5-C1814.00 Peka Peka to North Otaki 440PN Element -...

Documents

Transcript of Appendix 1: Waterway crossings - Home | NZ … - 5-C1814.00 Peka Peka to North Otaki 440PN Element -...