Effects of Rain Water Effects of Rain Water Harvesting on the Harvesting on the

HydrographHydrograph

Tyler JantzenTyler Jantzen

May 3, 2007May 3, 2007

CE 394K.2CE 394K.2

IntroductionIntroduction

What is Rain Water What is Rain Water Harvesting (RWH)?Harvesting (RWH)? Collect rain water Collect rain water

for for consumptiveconsumptive use use Increasing Increasing

popularitypopularity Third worldThird world Arid climatesArid climates ““sustainable” sustainable”

buildingbuilding

IntroductionIntroduction

AdvantagesAdvantages Reduce need for Reduce need for

expensive expensive infrastructureinfrastructure

Reduce dependence Reduce dependence on on aquiferaquifer use use

CleanClean, pH neutral , pH neutral Reduce Reduce utilityutility bills bills Reduce urban effects Reduce urban effects

on hydrographon hydrograph

DisadvantagesDisadvantages High fixed costsHigh fixed costs Reduce hydrograph Reduce hydrograph

below natural levelsbelow natural levels

ObjectivesObjectives

Hydrologic Model to Hydrologic Model to simulate Rain Water simulate Rain Water HarvestingHarvesting Urban areaUrban area Arid climateArid climate Use ArcGIS, HEC-Use ArcGIS, HEC-

GeoHMS, HEC-HMSGeoHMS, HEC-HMS

Multiple ScenariosMultiple Scenarios Pre-developedPre-developed 19921992 20012001 Rain Water HarvestingRain Water Harvesting

2%, 5%, 10%, 15%, 2%, 5%, 10%, 15%, 20%, 25%, 50%, 75%, 20%, 25%, 50%, 75%, 100% participation100% participation

At what % does rain At what % does rain water harvesting = water harvesting = pre-developed?pre-developed?

Study Area:Study Area:Rillito and Alamo Canyon Rillito and Alamo Canyon Watersheds- Tucson, AZWatersheds- Tucson, AZ

Rillito River Watershed too big!

Processing time too long.

Data CollectionData Collection

Basin delineationBasin delineation NHDPlusNHDPlus National Elevation National Elevation

Dataset (NED) DEM from Dataset (NED) DEM from USGSUSGS

Curve Number grid Curve Number grid creationcreation Soil parametersSoil parameters

SSURGO from USDASSURGO from USDA Land Use Land Use

National Land Cover National Land Cover Dataset Dataset

Data Pre-ProcessingData Pre-Processing

Land UseLand Use Re-classifyRe-classify

Assign Curve NumbersAssign Curve Numbers Curve Number LookupCurve Number Lookup Pre-Developed = Pre-Developed =

average of average of undevelopedundeveloped

Rain Water Harvesting; Rain Water Harvesting; 100% 100% →→ CN =0 CN =0

Combine Land Use and Combine Land Use and SoilsSoils

Create Curve Number Create Curve Number GridGrid

Run Arc-HydroRun Arc-Hydro

2001 NLCD Classification Revised Classification

Description Description

11 Open Water 19 Open Water

21 Developed, Open Space 14 Residentail- 1/2 acre lot

22 Developed, Low Intensity 13 Residential- 1/4 acre lot

23Developed, Medium

Intensity 12 Residential- 1/8 acre lot

24 Developed, High Intensity 10 Commercial and business

31 Barren Land 3 Pasture/Range- poor

41 Deciduous Forest 7 Wood or forest- good

42 Evergreen Forest 7 Wood or forest- good

43 Mixed Forest 7 Wood or forest- good

52 Scrub/Shrub 3 Pasture/Range- poor

71 Grassland/Herbaceous 5 Meadow

81 Pasture/Hay 4 Pasture/Range- good

82 Cultivated Crops 2Cultivated Land- w/o

Conservation

90 Woody Wetlands 19 Open Water

95Emergent Herbaceous

Wetland 19 Open Water

Soil Group

Land Cover Description Code A B C D

Cultivated Land- w/ Conservation 1 72 81 88 91

Cultivated Land- w/o Conservation 2 62 71 78 81

Pasture/Range- poor condition 3 68 79 86 89

Pasture/Range- good condition 4 39 61 74 80

Meadow 5 30 58 71 78

Wood or forest- poor cover 6 45 66 77 83

Wood or forest- good cover 7 25 55 70 77

Open spaces- good condition 8 39 61 74 80

Open spaces- fair condition 9 49 69 79 84

Commercial and business areas 10 89 92 94 95

Industrial districts 11 81 88 91 93

Residential- 1/8 acre lot 12 77 85 90 92

Residential- 1/4 acre lot 13 61 75 83 87

Residential- 1/2 acre lot 14 54 70 80 85

Parking lots 15 98 98 98 98

Paved street 16 98 98 98 98

Gravel street 17 76 85 89 91

Dirt street 18 72 82 87 89

Open Water 19 100 100 100 100

Soil Group

Land Cover Description Code A B C D

Cultivated Land- w/ Conservation 1 41.4 63.8 75.6 81.4

Cultivated Land- w/o Conservation 2 41.4 63.8 75.6 81.4

Pasture/Range- poor condition 3 68 79 86 89

Pasture/Range- good condition 4 39 61 74 80

Meadow 5 30 58 71 78

Wood or forest- poor cover 6 45 66 77 83

Wood or forest- good cover 7 25 55 70 77

Open spaces- good condition 8 41.4 63.8 75.6 81.4

Open spaces- fair condition 9 41.4 63.8 75.6 81.4

Commercial and business areas 10 41.4 63.8 75.6 81.4

Industrial districts 11 41.4 63.8 75.6 81.4

Residential- 1/8 acre lot 12 41.4 63.8 75.6 81.4

Residential- 1/4 acre lot 13 41.4 63.8 75.6 81.4

Residential- 1/2 acre lot 14 41.4 63.8 75.6 81.4

Parking lots 15 41.4 63.8 75.6 81.4

Paved street 16 41.4 63.8 75.6 81.4

Gravel street 17 41.4 63.8 75.6 81.4

Dirt street 18 41.4 63.8 75.6 81.4

Open Water 19 100 100 100 100

50% Rain Water Harvesting50% Rain Water Harvesting Soil Group

Land Cover Description Code A B C D

Cultivated Land- w/ Conservation 1 72 81 88 91

Cultivated Land- w/o Conservation 2 62 71 78 81

Pasture/Range- poor condition 3 68 79 86 89

Pasture/Range- good condition 4 39 61 74 80

Meadow 5 30 58 71 78

Wood or forest- poor cover 6 45 66 77 83

Wood or forest- good cover 7 25 55 70 77

Open spaces- good condition 8 39 61 74 80

Open spaces- fair condition 9 49 69 79 84

Commercial and business areas 10 44.5 46 47 47.5

Industrial districts 11 40.5 44 45.5 46.5

Residential- 1/8 acre lot 12 38.5 42.5 45 46

Residential- 1/4 acre lot 13 30.5 37.5 41.5 43.5

Residential- 1/2 acre lot 14 27 35 40 42.5

Parking lots 15 98 98 98 98

Paved street 16 98 98 98 98

Gravel street 17 76 85 89 91

Dirt street 18 72 82 87 89

Open Water 19 100 100 100 100

From SCS TR-55

=CNold*(100%-50%)

HEC-GeoHMS HEC-GeoHMS

Convert ArcGIS into Convert ArcGIS into HMSHMS ArcHydro, CN grid ArcHydro, CN grid

as inputas input Basin Parameters:Basin Parameters:

Slope, Centroid, Slope, Centroid, Elevation, Average Elevation, Average CN, Lag Time, AreaCN, Lag Time, Area

Reach Parameters:Reach Parameters: Slope, LengthSlope, Length

Extremely FinickyExtremely Finicky

HEC-HMS: Basin ModelHEC-HMS: Basin Model

Loss: SCS Curve Loss: SCS Curve NumberNumber

Transform: SCS Transform: SCS Unit HydrographUnit Hydrograph

Baseflow: noneBaseflow: none Routing: Kinematic Routing: Kinematic

WaveWave Loss/Gain: noneLoss/Gain: none

Average Basin Curve Number Comparison

68

7581 79 77

7369

6562

43

24

5

0

10

20

30

40

50

60

70

80

90

Pre D

evelo

pmen

t

1992

2001

2% R

WH

5% R

WH

10%

RW

H

15%

RW

H

20%

RW

H

25%

RW

H

50%

RW

H

75%

RW

H

100%

RW

H

Scenario

Cu

rve

Nu

mb

er

Different for each scenario

Same for all scenarios

HEC-HMS: Meteorologic HEC-HMS: Meteorologic ModelModel

SCS Type II, 30 SCS Type II, 30 minuteminute

Frequency (yr) 1 2 5 100

Duration (min) 30 30 30 30

Depth (in) 0.65 0.83 1.1 2

Depth (mm) 16.5 21.1 27.9 50.8

Actual storm: 8/8/05Actual storm: 8/8/05Hyetograph for 8/8/05, Tucson WBO Precipitation Gaging

Station (COOPID = 028820)

9

0

26

2 1

13

0

5

10

15

20

25

30

1:00 2:00 3:00 4:00 5:00 6:00

Time (hours on 8/8/05)In

cre

me

nta

l R

ain

De

pth

(h

un

dre

dth

s o

f a

n i

nc

h)

Results: HypothesisResults: Hypothesis

Post-Development Post-Development is is higherhigher, , flashierflashier than pre-than pre-developmentdevelopment

Rain water Rain water harvesting is harvesting is lowerlower, , less flashyless flashy than than post-development post-development

Flow

Time

Results: 100 Year StormResults: 100 Year StormModeled Response to 100 Year Storm

0

2

4

6

8

10

12

14

16

18

12:00 18:00 0:00 6:00 12:00 18:00 0:00 6:00 12:00

Time

Flo

w (

m3/

s)

Pre Developed 1992 2001 2%

5% 10% 15% 20%

25% 50% 75% 100%

Modeled Response to 100 Year Storm

0

2

4

6

8

10

12

14

16

18

12:00 18:00 0:00 6:00 12:00 18:00 0:00 6:00 12:00

Time

Flo

w (

m3/

s)

Pre Developed 1992 2001 15% 20%

ResultsResults

Used 15% RWH with multiple stormsUsed 15% RWH with multiple storms Only 100 yr storm produced runoffOnly 100 yr storm produced runoff Smaller storms (1 – 5 yr) had Smaller storms (1 – 5 yr) had no runoffno runoff

LimitationsLimitations

Much Much simplifiedsimplified hydrologic model hydrologic model 15% RWH = 15% of land use has CN 15% RWH = 15% of land use has CN

= 0= 0 Does not account for Does not account for area within land area within land

use that does not participate in RWHuse that does not participate in RWH 15% RWH 15% RWH ≠ 15% of population ≠ 15% of population

participating in RWHparticipating in RWH 15% RWH = 15% of 15% RWH = 15% of landland participating participating

ConclusionsConclusions

15% RWH 15% RWH ≈ Pre-Developed Conditions≈ Pre-Developed Conditions More than 15% RWH could have More than 15% RWH could have drastic drastic

effectseffects on urban hydrograph on urban hydrograph Coarse modelCoarse model

Somebody should refineSomebody should refine HEC-GeoHMS is a great tool but…HEC-GeoHMS is a great tool but…

It is extremely It is extremely finickyfinicky, and can be , and can be frustratingfrustrating

Questions?Questions?

If time allows…click here

Data SourcesData Sources

Tutorials: Tutorials: http://web.ics.purdue.edu/~vmerwade/tutorial.htmlhttp://web.ics.purdue.edu/~vmerwade/tutorial.html

NHDPlus: NHDPlus: http://www.horizon-systems.com/nhdplus/http://www.horizon-systems.com/nhdplus/ NED, NLCD: NED, NLCD: http://http://seamless.usgs.govseamless.usgs.gov// Land Use Classification: Land Use Classification:

http://www.epa.gov/mrlc/classification.htmlhttp://www.epa.gov/mrlc/classification.html SSURGO: SSURGO: http://soildatamart.nrcs.usda.gov/http://soildatamart.nrcs.usda.gov/ STATSGO: STATSGO:

http://www.soilinfo.psu.edu/index.cgi?soil_data&stathttp://www.soilinfo.psu.edu/index.cgi?soil_data&statsgosgo

Design Storm: Design Storm: http://http://hdsc.nws.noaa.gov/hdsc/pfds/sa/az_pfds.htmlhdsc.nws.noaa.gov/hdsc/pfds/sa/az_pfds.html

Rain gage data: Rain gage data: http://cdo.ncdc.noaa.gov/CDO/cdohttp://cdo.ncdc.noaa.gov/CDO/cdo