Effects%20of%20Rain%20Water%20Harvesting%20on%20the%20Hydrograph

1
Effects of Rain Water Harvesting on the Hydrograph

• Tyler Jantzen
• May 3, 2007
• CE 394K.2

2
Introduction

• What is Rain Water Harvesting (RWH)?
• Collect rain water for consumptive use
• Increasing popularity
• Third world
• Arid climates
• sustainable building

3
Introduction

• Advantages
• Reduce need for expensive infrastructure
• Reduce dependence on aquifer use
• Clean, pH neutral
• Reduce utility bills
• Reduce urban effects on hydrograph

• Disadvantages
• High fixed costs
• Reduce hydrograph below natural levels

4
Objectives

• Hydrologic Model to simulate Rain Water
  Harvesting
• Urban area
• Arid climate
• Use ArcGIS, HEC-GeoHMS, HEC-HMS

• Multiple Scenarios
• Pre-developed
• 1992
• 2001
• Rain Water Harvesting
• 2, 5, 10, 15, 20, 25, 50, 75, 100
  participation
• At what does rain water harvesting
  pre-developed?

5
Study AreaRillito and Alamo Canyon Watersheds-
Tucson, AZ
Rillito River Watershed too big! Processing
time too long.
6
Data Collection

• Basin delineation
• NHDPlus
• National Elevation Dataset (NED) DEM from USGS
• Curve Number grid creation
• Soil parameters
• SSURGO from USDA
• Land Use
• National Land Cover Dataset

7
Data Pre-Processing
From SCS TR-55
Soil Group Soil Group Soil Group 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 Soil Group Soil Group 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 Harvesting Soil Group Soil Group Soil Group 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
2001 NLCD Classification 2001 NLCD Classification Revised 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
23 Developed, 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 2 Cultivated Land- w/o Conservation
90 Woody Wetlands 19 Open Water
95 Emergent Herbaceous Wetland 19 Open Water

• Land Use
• Re-classify
• Assign Curve Numbers
• Curve Number Lookup
• Pre-Developed average of undeveloped
• Rain Water Harvesting 100 ? CN 0
• Combine Land Use and Soils
• Create Curve Number Grid
• Run Arc-Hydro

CNold(100-50)
8
HEC-GeoHMS

• Convert ArcGIS into HMS
• ArcHydro, CN grid as input
• Basin Parameters
• Slope, Centroid, Elevation, Average CN, Lag Time,
  Area
• Reach Parameters
• Slope, Length
• Extremely Finicky

9
HEC-HMS Basin Model
Different for each scenario

• Loss SCS Curve Number
• Transform SCS Unit Hydrograph
• Baseflow none
• Routing Kinematic Wave
• Loss/Gain none

Same for all scenarios
10
HEC-HMS Meteorologic Model
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

• SCS Type II, 30 minute

• Actual storm 8/8/05

11
Results Hypothesis

• Post-Development is higher, flashier than
  pre-development
• Rain water harvesting is lower, less flashy than
  post-development

12
Results 100 Year Storm
13
Results

• Used 15 RWH with multiple storms
• Only 100 yr storm produced runoff
• Smaller storms (1 5 yr) had no runoff

14
Limitations

• Much simplified hydrologic model
• 15 RWH 15 of land use has CN 0
• Does not account for area within land use that
  does not participate in RWH
• 15 RWH ? 15 of population participating in RWH
• 15 RWH 15 of land participating

15
Conclusions

• 15 RWH Pre-Developed Conditions
• More than 15 RWH could have drastic effects on
  urban hydrograph
• Coarse model
• Somebody should refine
• HEC-GeoHMS is a great tool but
• It is extremely finicky, and can be frustrating

16
Questions?
If time allowsclick here
17
Data Sources

• Tutorials http//web.ics.purdue.edu/vmerwade/tut
  orial.html
• NHDPlus http//www.horizon-systems.com/nhdplus/
• NED, NLCD http//seamless.usgs.gov/
• Land Use Classification http//www.epa.gov/mrlc/c
  lassification.html
• SSURGO http//soildatamart.nrcs.usda.gov/
• STATSGO http//www.soilinfo.psu.edu/index.cgi?soi
  l_datastatsgo
• Design Storm http//hdsc.nws.noaa.gov/hdsc/pfds/s
  a/az_pfds.html
• Rain gage data http//cdo.ncdc.noaa.gov/CDO/cdo