STORM REPORT
Summer/Autumn Storms of 2000
August 29th, October 10th, October 21st-23rd, October 27th

Flood Control District of Maricopa County
2801 W. Durango Street
Phoenix, AZ 85009
(602) 506-1501

Prepared by:
Stephen D. Waters, E. Jim Perfrement & David E. Gardner
Engineering Division, Flood Warning Branch
December, 2000
Revised Feb. 1, 2001

Table of Contents

Page

Introduction ....................................................................................................2

Meteorology....................................................................................................3

Precipitation....................................................................................................6

Runoff ............................................................................................................7

ALERT System Performance..........................................................................17

Summary.........................................................................................................20

Appendix A: Selected Meteorological Services Program Outlooks
and Messages ..................................................................................................21
Appendix B: Point Rainfall Maps and Isohyetal Rainfall Coverage Maps
from FCD Automated Gage Data....................................................................29
Appendix C: NEXRAD Reflectivity Images from Phoenix WFO ...................34
Appendix D: Depth/Duration/Frequency Plots and Histograms for Seven
Selected Stations ............................................................................................37
Appendix E: Selected Digital Photos .............................................................48
1

INTRODUCTION

A number of heavy thunderstorms dropped large amounts of rain in the Wickenburg area, lower
Hassayampa and upper Centennial watersheds on August 29th, 2000. These storms caused flooding
along several watercourses in northwestern Maricopa County and eastern La Paz County, including
Martinez Creek, Sols Wash and Centennial Wash.
The month of October featured a series of Pacific low-pressure frontal systems which tapped tropical
moisture in northern Mexico as they passed through the State, resulting in heavy widespread rain with
numerous embedded thunderstorms. Again, the Wickenburg and Centennial areas were affected, along
with Grass Wash, Tiger Wash, Jackrabbit Wash and much of northern Maricopa County.
The purpose of this report is to present in a concise manner selected rainfall, runoff, graphical and
statistical data from the storm events of August 29, October 10, October 21-23 and October 27, 2000.
The majority of the data presented was collected by the Flood Control District's (FCD) ALERT
System, with contributions from the Phoenix National Weather Service (NWS) Forecast Office and the
United States Geological Survey (USGS) surface-water data collection program.
The goal of this report is to present data and derived products for general information purposes, and as
a guide for future prediction of water levels and discharge rates in the watersheds affected by flooding.
DISCLAIMER: Although these data have been reviewed and/or edited they may be subject to
significant change. Data users are cautioned to consider carefully the provisional nature of this
information before using it for decisions that concern personal or public safety or the conduct of
business that involves substantial monetary or operational consequences.
This report and the data contained within it, as well as the entire compliment of real-time and historic
FCD ALERT data can be viewed or downloaded from our website at:
http://www.fcd.maricopa.gov/alert/alert.htm
Also, a Compact Disk containing this report and all associated tables and graphics can be ordered from
the FCD at the address on the report cover page or by calling (602) 506-8701.

2

METEOROLOGY
August 29,2000
On the 29th of August the atmosphere over central and southern Arizona was very moist, possibly the
most moisture available for shower and thunderstorm development of any day during the 2000
monsoon season. As for a trigger (dynamics) to get storms going, there was a lower/mid level
atmospheric disturbance forecast to move north/northwest through the state. Also, in the upper levels
of the atmosphere, there was a disturbance off the California coast - aiding the import of moisture from
the south, as well as acting as an additional trigger for storm development.
The precipitable water at 5 AM was 1.84 inches, the 850mb dewpoint was >14 degrees, and the 600mb
dewpoint depression was <2 degrees - collectively a strong indicator of very moist air from the surface
to over 15,000 feet altitude. The only concern, which could inhibit storm development, was existing
cloud cover and relatively cool temperatures - but as it turned out these concerns didn't materialize.
A few showers and thunderstorms developed on the 28th, continued to develop and became stronger
late that night and peaked on the morning of the 29th. Moisture at lower and middle levels of the
atmosphere continued to be pumped into Maricopa County from the south (Mexico/Gulf of Mexico)
through most of the day. Thus there was no drying of consequence following the initial outbreak of
showers. To make matters worse, the storm moved at a relatively slow speed (mostly 12-15 mph),
allowing locally heavy rain to remain over an area for a period of time. The storm center finally
moved north of the County during the night of the 29th.

October 2000
A series of weather disturbances moved south/southeast from the northern Pacific (a pattern referred to
as split flow) - for the extended period of mid October into November. Although this is not an overly
unusual trend or general track, what was different was the extended period of time that was involved,
the strength of the systems and the track's location so far south for the time-of-year (into Arizona).
Normally only one or two of these disturbances will become moderately strong, but this time most
resulted in periods of moderate to heavy rain for Maricopa County. As a result our (calendar) annual
rain accumulation went from a deficit to above normal.

October 10, 2000
On the 9th of October weather maps showed a large upper-level atmospheric weather disturbance
sliding south along the west coast. At lower and mid levels of the atmosphere moisture from the subtropics was advected north, via south to southeast winds, into Maricopa County. And lastly, there was
a strong cold front moving east through southern California - located along a north-south line near the
western border of Arizona the morning of the10th, moving east to roughly a Page to Blythe line by
around noon.

3

This resulted in a moist atmosphere that was "triggered" by the approaching disturbance and associated
cold front. The end result was short-lived, locally-heavy morning rain in the Phoenix area - which
moved east and northeast with time.
Farther to the south, over northern Mexico, there were remnants of tropical storm Olivia, but it's
doubtful that this system had much of an impact on what took place over Maricopa County. Most of
the moisture associated with Olivia was advected eastward into New Mexico and Texas.

October 21- 23, 2000
To set the stage for this event a few showers and thunderstorms moved through Maricopa County on
the 19th (Thursday). Local rain accumulations amounted to .25 to .50 inch. This rain was the result of
the first in an extended series of upper level weather disturbances that moved south/southeast into our
area during October/November.
It was dry on the 20th (Friday), as Maricopa County was between disturbances. But an approaching
strong cold upper atmospheric weather disturbance (from the northwest) resulted in the development of
scattered showers and thunderstorms Friday night and Saturday morning.
This Pacific storm had considerable moisture associated with it, and moved into an area that was
already moist due to residual moisture associated with the disturbance that moved east across southern
Arizona on the 19th.
Numerical guidance, as early as Wednesday (18th), suggested the threat of rain for the weekend. And
by Friday guidance indicated the threat of heavy rain - to over an inch. With the Saturday "Weather
Outlook" issued at 1:10 PM, clients were alerted to break out their Flood Response Plans and prepare
for a significant rain event.
The heaviest and most destructive rains fell Saturday evening (21st) - with portions of western
Maricopa County receiving over 3 inches of rain. Especially hard hit, as a result of the heavy rain,
were Centennial Wash (flow into Wenden), Wickenburg (Sols Wash) and Skunk Creek.
The associated upper level disturbance was slow to leave the area. As a result additional rains fell
Saturday night and Sunday, with the storm exiting to the north and east Sunday night and Monday.
But the heaviest rains by Sunday (to over an inch) were over the east and northern fringes of the
County - not the same area hit hard Saturday evening.

October 27, 2000
The major storm that took place October 21-23 left the soil very wet - possibly saturated in many
areas. Thus additional rain would become mostly runoff. The weather disturbance that moved toward
Maricopa County on the 26th and 27th, like previous disturbances, moved into the area from the
northwest.

4

This weather disturbance had an unseasonably strong cold front associated with it. Wednesday
morning the front was positioned north-south over far southeast California and eastern Nevada. By
Wednesday evening the front was north-south through central Arizona. By Thursday morning (27th) it
had dissipated east of the County, but a secondary front, or trough, developed back near the
Arizona/California border. This latter feature was probably a significant trigger that aided development
of the locally heavy rain that followed.
The advection of moisture from Mexico was probably not overly noteworthy, compared to the
disturbance 5 days earlier, but as mentioned the ground was already very moist. And the upper level
disturbance was very strong - resulting in good dynamics to act on the existing moisture.
Showers and thunderstorms moved into the area from the west, again hitting northwest Maricopa
County with locally heavy rain. The main band of rain (north-south orientation) was very slow to
move east. By late morning (27th) some areas west and southwest of Wickenburg reported rain
accumulations of over an inch, and locally heavy rain remained in the general Wickenburg area into
the afternoon hours.
During the afternoon the heaviest rains slowly moved east toward the central portion of the County.
By late afternoon the heaviest rains were centered over the central portion of the County; and by
evening the heaviest rains were over the far eastern portion of the County - as the associated weather
disturbance started to move away from the area. But local showers persisted over much of the County
through the evening.
Appendix A contains selected Outlook and Message Products from our Meteorological Services
Program (MSP). The MSP provides heavy rainfall and severe weather forecast products to emergency
management agencies, public works and transportation agencies, engineering departments, law
enforcement, and fire departments and recreation departments within Maricopa County.

5

PRECIPITATION
A series of heavy thunderstorms dropped large amounts of rain in the Wickenburg area, lower Hassayampa and
upper Centennial watersheds on August 29th , 2000. These storms caused flooding along several watercourses in
northwestern Maricopa County and eastern La Paz County, including Martinez Creek, Sols Wash and
Centennial Wash. Rain fell in general from 7:00 AM through 2:00 PM.
The month of October featured consecutive Pacific low-pressure frontal systems which tapped tropical moisture
in northern Mexico and the Gulf of California as they passed through the State, resulting in heavy widespread
rain with numerous embedded thunderstorms. The heavy event periods were from 4:00 AM through 11:00 AM
on the 10th , 7:00 PM on the 21s t through 11:00 AM on the 22nd (with scattered showers on the 23rd ), and 7:00
AM through 6:00 PM on the 27th . Again, the Wickenburg and Centennial areas were affected, along with Grass
Wash, Tiger Wash, Jackrabbit Wash and much of northern Maricopa County, including Skunk Creek, New
River and Cave Creek.
The following Table 1 lists selected frequency statistics at seven automated ALERT Stations:

Gage ID

Gage Name

Storm
Date

Depth
(inches)

Duration
(hours)

Return Period /
Duration

7030
5275

Sols Tank
Sols Wash

8/29/00
8/29/00

3.50
4.61

12
12

60 yr - 12 hr.
>100 yr - 12 hr.

4930

Carefree Ranch

10/22/00

2.09

24

2 yr - 24 hr.

7120

Wickenburg Airport

10/22/00

2.87

2

100 yr - 2 hr.

5190

Smith Peak

10/22/00

3.27

24

30 yr - 6 hr.

5640

Cooks Mesa

10/22/00

3.98

24

40 yr - 12 hr.

5180

Centennial Wash

10/27/00

2.56

6

30 yr - 6 hr.

For general locations of these gages and the graphs used to create this table, see Appendix D

Appendix B contains four pages showing two graphics for each storm. The first is a map of the County showing
point rainfall totals measured by the ALERT automated gages. The rainfall period and ending time are shown at
the bottom. The second graphic is a contoured rainfall map using the point values from the first map. It covers
the same time period but may focus on areas of interest.
Appendix C contains several NEXRAD radar images from the storms in 1-hour, 3-hour and Storm Total
formats, courtesy of Phoenix WFO. Appendix D displays depth/duration/frequency plots and histograms for
seven selected stations. Additional detailed rainfall information is available on the web at:
http://156.42.96.39/showrain.html or http://156.42.96.39/alert/raindata.html.
6

RUNOFF
The storm of August 29th featured significant runoff events in the Wickenburg area and in the
Centennial watershed. Flows in these areas had estimated return periods of between 8 and 17 years.
On October 10th, flows in central Phoenix and Scottsdale were generally around a 2-year return period.
But the rains from this storms served to wet many watersheds around the County, which added to the
runoff potential for subsequent storms.
October 21st through 23 rd saw heavy runoff in the northern, central, western and northwestern portions
of the County. Centennial Wash experienced what is believed to be a 100-year event, Sols Wash saw a
66-year return period event, Flying E Wash in Wickenburg around a 40, and Hartman and Tiger
Washes approximately 16-year events.
Flows during the October 27th storm were again heavy in the western and northwestern parts of the
County. Jackrabbit Wash experienced a 50-year flood, Hassayampa @ I-10 recorded a 70-year event,
Casandro Wash in Wickenburg suffered a 40-year, and Sols Wash and Tiger Wash each were deluged
by 10-year events.
Table 2 on the following page lists significant discharge peaks and return periods for selected FCD
stream gages. Table 3 presents peak stage and discharge values at all FCD water-level stations.
Following Table 3 are three selected hydrograph plots showing travel and warning times.

7

TABLE 2
Significant Discharge Peaks and Return Periods for Automated ALERT Stream Gages
GAGE
NAME

GAGE
ID

STORM
DATE

PEAK
DISCHARGE (cfs)

RETURN
PERIOD (years)

Centennial @ Wenden
Hassayampa @ US 60
Martinez Creek
Powderhouse Wash
Sols Wash nr Matthie

5093
5228
7013
7113
7043

08/29/00
08/29/00
08/29/00
08/29/00
08/29/00

4,850
5,625
7,270
515
5,240

10 (a)
8 % of Q100 (a)
8 (a)
17 (a)
13 (a)

ACDC @ 43rd Ave.
ACDC @ 67th Ave.
Berneil Wash
EMF @ Broadway
IBW @ Shea Blvd.

4821
5523
4688
6573
4693

10/10/00
10/10/00
10/10/00
10/10/00
10/10/00

395
375
305
504
1,250

< 2 (b)
< 2 (b)
15 % of Design Q
14 % of Q100 (a)
14 % of Q100 (a)

ACDC @ 43rd Ave.
Adobe Dam Outflow
Bullard Wash
Cave Buttes Dam Outflow
Centennial @ Wenden
Delaney Wash
EMF @ Queen Creek Rd.
Flying E Wash
Greene Wash @ SR 84
Hartman Wash
Hassayampa @ US 60
Hassayampa nr Morristown
Martinez Creek
New River Dam Outflow
Powderhouse Wash
Santa Cruz @ SR 84
Skunk Creek @ I-17
Sols Wash nr Matthie
Tiger Wash
Waterman Wash

4821
5538
6863
4899
5093
5108
6583
7083
0793
7063
5228
5223
7013
5609
7113
0788
5568
7043
5163
6833

10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00
10/21-23/00

360
497
250
206
24,250
260
574
3,675
1,155
2,350
15,400
5,240
890
440
350
1,260
2,320
10,800
3,850
1,980

< 2 (b)
NA
NA
NA
~ 100 (a)
NA
NA
40 (a)
NA
16 (c)
22 % of Q100 (a)
3 (c)
< 2 (a)
NA
12 (a)
NA
4 (c)
66 (a)
16 (c)
~7 % of Q100 (a)

ACDC @ 43rd Ave.
Agua Fria @ Grand Ave.
Casandro Wash
Centennial @ Wenden
EMF @ Queen Creek
Gila River @ Olberg
Hartman Wash
Hassy @ Box Canyon

4821
5503
7093
5093
6583
0783
7063
5308

10/27/00
10/27/00
10/27/00
10/27/00
10/27/00
10/27/00
10/27/00
10/27/00

880
5,839
400
11,150
2,460
2,590
1,050
3,215

< 2 (b)
NA
46 (a)
28 (a)
NA
< 2 (a)
6 (c)
2 (c)

8

GAGE
NAME
Hassayampa @ I-10
Hassayampa @ US 60
Jackrabbit Wash
Martinez Creek
New River @ Glendale
Scatter Wash
Skunk Creek @ I-17
Sols Wash nr Matthie
Tiger Wash

GAGE
ID
5283
5228
5218
7013
5508
5543
5568
7043
5163

STORM
DATE
10/27/00
10/27/00
10/27/00
10/27/00
10/27/00
10/27/00
10/27/00
10/27/00
10/27/00

PEAK
DISCHARGE (cfs)
40,800
8,070
32,400
2,650
2,450
490
480
4,760
3,170

RETURN
PERIOD (years)
70 (a)
12 % of Q100 (a)
>100 (c)
4 (a)
< 2 (a)
9 (a)
< 2 (c)
10 (a)
10 (a)

"Q" refers to discharge; Q 100 is the 100-year or Regulatory Discharge
(a) - Return period estimated from Flood Insurance Study rainfall/runoff modeling
(b) - Return period estimated from structure design report
(c) - Return period estimated from streamflow data recorded prior to these storms
NA - Not Available
Values in Blue are computed from and/or verified by slope/area survey computations and/or highwater marks. Values in Green are provided by USGS. Values in Red were changed or included in the
02/01/2001 revision.
To find the location of an ALERT water-level station, point your browser to
http://www.fcd.maricopa.gov/alert/alert.htm and use the "Station Location Maps" tool. Additional
stage and discharge information is available on the web at: http://156.42.96.39/showflow.html

9

TABLE 3 - Peak Stage and Discharge Values at FCDMC Water-level Stations
GAGE_ID

4818
4813
4808
4821
5523
5538
5534
5403
5503
6673
5988
4688
5203
5208
6813
6863
7133
7093
4903
4899
4918
4923
4833
5093
5103
5408
5013
6623

NAME

10th St. Wash Basin #1
ACDC @ 14th St.
ACDC @ 36th St.
ACDC @ 43rd Ave.
ACDC @ 67th Ave.
Adobe Dam Outlet
Adobe Dam Pool
Agua Fria @ Buckeye
Agua Fria @ Grand
Apache Junction FRS
Aspen Dam
Berneil Wash
Buckeye FRS #1
Buckeye FRS #2
Buckeye FRS #3
Bullard Wash
Casandro Dam
Casandro Wash
Cave Buttes Dam Outlet
Cave Buttes Dam Pool
Cave Cr. nr Cave Cr.
Cave Cr. @ Spur Cross
Cave Cr. @ Cactus
Centennial @ Wenden
Centennial Railroad
Colter @ El Mirage
Columbus Wash
Crossroads Park

10/27/00 10/27/00 10/22/00
Q
Stage
Q
9
1.40
17
27
0.70
0
7
1.02
3
880
2.25
360
417
3.42
271
154
2.45
497
196
4.58
419
1,288
0.15
433
5,839
6.46
10
26
4.23
25
36
2.28
7
100
0.70
297
0
0.00
0
0
0.00
0
0
0.00
0
243
1.04
250
15
7.22
14
400
1.20
74
21
1.60
29
163
10.49
206
221
1.10
590
180
4.33
635
222
8.58
386
11,150
5.68
24,250
0
0.00
180
135
1.45
31
0
0.00
0
0
0.00
0

10

PEAKS
10/22/00 10/10/00 10/10/00
Stage
Q
Stage
2.10
0
0.00
0.00
0
0.00
0.47
3
0.47
1.44
395
1.51
2.95
375
3.30
4.45
0
0.00
8.20
0
0.00
-0.38
433
-0.38
2.95
0
0.00
3.98
0
0.00
0.66
10
0.86
1.35
305
1.38
0.00
0
0.00
0.00
0
0.00
0.00
0
0.00
1.01
0
0.00
5.27
0
0.00
0.82
0
0.00
1.80
31
1.87
18.56
0
0.00
2.12
0
0.00
5.83
0
0.00
10.33
138
4.76
7.82
0
0.00
3.10
0
0.00
0.60
0
0.00
0.00
0
0.00
0.00
0
0.00

8/29/00
Q
1
0
0
0
81
0
0
0
0
0
0
46
0
0
0
0
13
147
0
0
0
0
62
4,850
0
0
0
0

8/29/00
Stage
0.50
0.00
0.00
0.00
1.90
0.00
0.00
0.00
0.00
0.00
0.00
0.43
0.00
0.00
0.00
0.00
4.29
1.42
0.00
0.00
0.00
0.00
2.70
3.92
0.00
0.00
0.00
0.00

GAGE_ID

5108
4803
5422
5413
4648
4683
4658
4668
6598
6573
6583
6893
7083
6608
6853
778
783
6848
5978
793
6603
6503
5128
7063
5228
5308
5283
5353
5223
5993
4613
4618

NAME

Delaney Wash
Dreamy Draw Dam
Dysart @ El Mirage
Dysart @ LAFB
E. Fork Cave Cr. #1
E. Fork Cave Cr. #3
E. Fork Cave Cr. #4
EFCC nr 7th Ave.
EMF @ AZ Ave.
EMF @ Broadway
EMF @ Queen Cr.
Estrella Fan
Flying E Wash
Freestone Basin
Gila @ Estrella Pkwy.
Gila @ Maricopa Rd.
Gila @ Olberg
Gila @ 116th Ave.
Golden Eagle Park Dam
Greene Wash @ SR 84
Guadalupe Channel
Guadalupe FRS
Harquahala FRS
Hartman Wash
Hassayampa @ US 60
Hassy @ Box Canyon
Hassayampa @ I-10
Hassy @ Wagoner Rd.
Hassy @ Morristown
Hesperus Dam
IBW @ Indian Bend Rd.
IBW @ Indian School

PEAKS
10/27/00 10/27/00 10/22/00 10/22/00 10/10/00 10/10/00
Q
Stage
Q
Stage
Q
Stage
98
2.04
260
2.77
203
2.52
22
1.98
0
0.00
51
3.44
311
3.18
92
1.62
4
0.28
113
1.47
19
0.55
0
0.00
0
0.00
0
0.00
0
0.00
0
0.00
0
0.00
14
0.45
21
1.58
14
1.17
41
2.58
15
0.40
15
0.40
116
1.62
1,025
1.85
198
0.65
0
0.00
650
1.87
80
0.75
504
1.62
2,460
3.80
574
1.65
0
0.00
0
0.00
0
0.00
0
0.00
263
1.75
3,675
5.60
0
0.00
0
1.23
0
1.25
0
0.00
1,900
6.95
1,500
6.60
0
0.00
71
2.04
0
0.00
0
0.00
2,590
3.40
980
1.67
0
0.00
0
0.00
0
0.00
0
0.00
136
6.52
28
5.52
39
5.66
80
0.52
1,155
3.28
0
0.00
526
1.98
235
1.25
0
0.00
0
0.00
0
4.07
0
0.00
375
22.80
0
0.87
0
0.00
1,050
3.68
2,350
6.16
0
0.00
15,400
4.90
0
0.00
0
0.00
3,215
7.20
1,020
4.93
0
0.00
40,800
7.05
0
0.00
0
0.00
39
3.84
156
4.66
0
0.00
7,030
11.73
5,240
11.10
0
0.00
45
3.09
0
0.00
0
0.00
211
2.00
177
1.83
238
2.12
239
2.56
253
2.59
267
2.62

11

8/29/00
Q
32
0
0
0
4
28
56
94
0
0
144
0
211
0
0
0
106
0
0
0
0
0
0
313
5,625
636
0
13
1,310
0
14
0

8/29/00
Stage
1.48
0.00
0.00
0.00
0.57
0.95
3.15
1.42
0.00
0.00
0.68
0.00
1.55
4.68
0.00
0.00
0.60
0.00
0.00
0.00
0.00
0.00
0.00
1.58
2.90
4.33
0.00
3.31
10.90
0.00
0.50
0.00

GAGE_ID

4628
4603
4693
4643
4623
5218
4678
7013
5448
5438
5598
5613
5609
5508
5983
4748
7113
6683
6707
6723
4863
6703
5113
4523
788
798
6923
5543
6628
5583
5568
7043

NAME

IBW @ McDonald
IBW @ McKellips
IBW @ Shea Blvd.
IBW @ Sweetwater
Interceptor Channel IBW
Jackrabbit Wash
Lake Marguarite
Martinez Creek
McMicken Dam
McMicken Floodway
New River @ Bell
New River Dam Outlet
New River Dam Pool
New River @ Glendale
North Heights Dam
Old Crosscut @ McDowell
Powderhouse Wash
Powerline FRS
Queen Cr. @ Rittenhouse
Queen Cr. @ CAP
Rawhide Wash
Rittenhouse FRS
Saddleback FRS
Salt River @ Priest
Santa Cruz @ SR 84
Santa Rosa @ SR 84
Sauceda Wash
Scatter Wash
Signal Butte FRS
Skunk Cr. nr New River
Skunk Cr. @ I-17
Sols Wash nr Matthie

PEAKS
10/27/00 10/27/00 10/22/00 10/22/00 10/10/00 10/10/00
Q
Stage
Q
Stage
Q
Stage
485
0.95
412
0.90
511
0.98
210
1.42
114
1.15
190
1.38
200
1.25
200
1.25
1,250
2.50
292
2.00
271
1.91
924
3.69
37
0.60
65
0.98
5
0.12
32,400
8.50
0
0.00
0
0.00
160
1.30
195
1.52
160
1.30
2,650
6.30
890
4.00
0
0.00
0
0.60
0
0.00
0
0.00
8
0.35
5
0.20
0
0.00
430
1.05
396
1.00
0
0.00
411
5.82
390
5.72
0
0.00
440
6.70
440
6.70
0
0.00
2,450
2.11
420
1.30
209
1.20
0
0.00
0
0.00
0
0.00
78
0.61
68
0.53
71
0.56
760
1.50
350
1.02
0
0.00
32
2.67
29
2.50
5
0.73
0
0.00
0
0.00
0
0.00
445
4.60
454
4.65
0
0.00
0
0.00
0
0.00
70
1.00
85
6.83
89
7.38
9
1.23
47
1.00
29
0.60
0
0.00
1,220
3.38
1,785
3.62
0
0.00
200
2.03
1,260
3.90
0
0.00
0
0.00
575
0.41
0
0.00
0
0.00
0
0.00
0
0.00
490
1.33
83
0.50
28
0.40
0
0.00
0
0.00
0
0.00
172
2.00
687
3.50
0
0.00
480
2.16
2,320
3.37
0
0.00
4,760
3.22
10,800
5.15
0
0.00

12

8/29/00
Q
0
0
142
241
0
0
0
7,270
0
0
0
0
0
0
0
0
515
5
0
198
0
27
0
0
84
0
0
255
0
0
0
5,240

8/29/00
Stage
0.00
0.00
1.10
1.77
0.00
0.00
0.00
8.32
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1.23
0.68
0.00
3.08
0.00
2.40
0.00
0.00
1.38
0.00
0.00
0.90
0.00
0.00
0.00
3.40

GAGE_ID

6563
4563
5968
5973
5248
5233
4638
4653
773
5163
6983
6688
6833
5418
6823
6739
5118

NAME

South Mtn. Fan
Spookhill FRS
Stone Ridge Dam
Sun Ridge Canyon Dam
Sunnycove FRS
Sunset FRS
Tatum Basin Inflow
Tatum Basin Outflow
Tat Momolikot Dam
Tiger Wash
Vekol Wash
Vineyard FRS
Waterman @ Rainbow
White Tank FRS #3
White Tank FRS #4
Whitlow Ranch Dam
Winters Wash
Values in BLUE are
computed from slope/area
survey computations and/or
high-water marks
Values in Red were
changed or included in the
02/01/2001 revision.
Values in GREEN are
provided by USGS

PEAKS
10/27/00 10/27/00 10/22/00 10/22/00 10/10/00 10/10/00
Q
Stage
Q
Stage
Q
Stage
14
0.38
0
0.00
14
0.38
43
6.26
32
4.44
36
5.04
39
4.43
0
0.75
0
0.75
28
1.95
0
0.00
0
0.00
38
15.16
29
6.51
0
0.00
25
8.43
23
7.03
0
0.00
8
0.20
0
0.00
0
0.00
0
0.00
0
0.00
0
0.00
0
4.01
0
0.00
0
0.00
3,170
7.40
3,850
7.84
0
0.00
0
0.00
0
0.00
0
0.00
61
3.40
20
1.85
0
0.00
130
3.08
1,980
8.77
0
0.00
0
0.00
0
0.00
0
0.00
0
0.00
0
0.00
0
0.00
0
0.00
0
0.00
0
0.00
44
0.92
0
0.00
0
0.00

13

8/29/00
Q
0
0
0
0
34
24
0
0
0
0
0
6
0
0
0
0
0

8/29/00
Stage
0.00
0.00
0.00
0.00
10.63
7.78
0.00
0.00
4.53
0.00
0.00
0.93
0.00
0.00
0.00
0.00
0.00

This graph shows the Sols Wash runoff event of August 29th (navy), along with
rainfall from the Sols Tank raingage (magenta). Note the time-to-peak is around 3
hours and that a warning was issued approximately 2 hours before the peak flow
reached downtown Wickenburg. This runoff event had a discharge peak of 5,240
cfs which translates to a return period of approximately 13 years.

14

This graph shows the Sols Wash runoff event of 10/21(navy), along with rainfall
from the Sols Wash raingage (magenta). Note here that the time-to-peak is only 30
minutes, and that a warning was issued approximately 1 hour before the peak flow
reached downtown Wickenburg. This runoff event had a discharge peak of 10,800
cfs which translates to a return period of approximately 66 years.

15

This graph shows the Centennial Wash runoff event of 10/22. Note here that the
time-to-peak is 7 hours, and that a warning was issued approximately 4 hours
before the peak flow reached Wenden. This runoff event had a discharge peak of
approximately 22,000 cfs which translates to a return period of around 100 years.

16

ALERT SYSTEM PERFORMANCE
During the storms of August 29th through October 27th, 2000 the FCD ALERT System consisted
of approximately 238 automated rain sensors and 106 automated water-level sensors.
On the August 29th storm only one rain/water-level station failed to operate - Agua Fria @
Buckeye Road.
The October 10th storm saw two rain/water-level stations fail due to lightning strikes - ACDC at
14th Street and ACDC @ 36th Street. Sunset Dam rain/water-level station was down because of a
failed battery. The IBW @ McKellips Rd. and Hesperus Dam raingages did not operate properly
because of plugged funnels. The Delaney Wash and Flying E Tank raingages were down
because of programming errors, and the Buckeye @ 547th Ave. and Freestone Basin raingages
were down for unknown reasons.
On October 19th a lightning strike hit a power pole across the street from the FCD office
building, sending a surge across data and phone lines which destroyed four modems and two
multi-port boards. As a result the ALERT base station was down from approximately 08:45
through 11:30. Steps are being taken to make sure this does not happen in the future.
The storm of October 21st-23rd saw inaccurate readings from the water-level sensors at Flying E
and Hartman Washes, but did not hamper the generation of warnings for these areas. The
Pinacle Peak Vista raingage was down due to transmitter failure, and the ASU South raingage
was down due to battery failure. The IBW @ McKellips raingage was still inoperative because
of a plugged funnel.
On October 27th the Hartman and Flying E Wash gages were still sending inaccurate data, and
IBW @ McKellips raingage still had a plugged funnel, but all other stations worked properly.
The following Table (4) lists most of warnings and information disseminated during the storms
by FCD ALERT personnel. We were unable to log all of the warnings for various reasons, and
are working to resolve this for future event logs.

TABLE 4
Date_Time
8/29/00 10:00 AM

Agency
Wickenburg Police
Dispatch

8/29/00 12:41 PM

MCDOT Radio Room

8/29/00 1:24 PM

Wickenburg Police
Dispatch

8/29/00 2:02 PM

MCDOT Radio Room

8/30/00 9:00 AM

La Paz County
Emergency
Management

Message Description
Martinez creek has substantial flow, expect a large flow on Sols
Wash in 30-45 minutes.
Hassayampa may get going enough later to warrant closing
Patton Road
Told them to expect a flood on Sols Wash, comparable to Nora,
at around 4:00 to 5:00 PM today.
Alarm at Hassy/Morristown, told her we would need to close
Hassy @ Patton Rd.
Told them of a report from field crew of flooded trailers in the
Wenden area due to breakout of Centennial Wash. Centennial @
Wenden currently flowing at 3,400 cfs.

17

8/30/00 10:08 AM

MCDOT Radio Room

10/10/00 7:02 AM

Glendale Police
Dispatch

10/21/00 8:57 PM

Wickenburg Police
Dispatch

10/22/00 2:45 AM

NWS - Phoenix

10/22/00 6:00 AM

NWS - Phoenix

10/22/00 3:00 PM

MCDOT

10/22/00 3:20 PM

MCDEM

10/22/00 5:30 PM

Southern Pacific
Railroad

10/23/00 11:00 AM

CAP

10/24/00 9:00 AM

MCDEM

10/24/00 3:00 PM

10/27/00 11:15 AM

MCDOT
La Paz County
Emergency
Management
La Paz County
Emergency
Management
La Paz County
Emergency
Management
Wickenburg Police
Dispatch
Scottsdale Fire
Wickenburg Police
Dispatch
MCDOT

10/27/00 11:45 AM

CAP

10/27/00 12:15 PM

NWS at Wenden

10/27/00 7:15 AM

10/27/00 8:55 AM
10/27/00 9:00 AM
10/27/00 9:15 AM
10/27/00 10:27 AM
10/27/00 10:55 AM

10/27/00 12:40 PM
10/27/00 4:15 PM
10/27/00 4:30 PM
10/27/00 5:45 PM
10/27/00 8:00 PM

Wickenburg Police
Dispatch
Wickenburg Police
Dispatch
Scottsdale Fire
La Paz County
Emergency
Management
MCDOT

Report from field crew of damage around SR71 bridge over
Centennial Wash, also nearby Railroad bridge, also a heads up for
flows coming down the wash past I-10 into Harquhala Valley.
Told them we were measuring 200 cfs at 43rd Ave, but did not
expect it to go much higher unless more rain moved in from the
west
Told them I expected a large flood on Sols given the
contributions from Flying E and Hartman. Several other calls
both ways as the event progressed.
Increasing flow in Centennial - suggested a warning for the
Wenden area, and alert citizens of possible evacuation.
Flow in Centennial at 19,000 cfs - pleaded with them to spread
word and get people out.
Advised them to monitor or close old US80 by dark - due to
waters within Centennial Wash.
Wanted info on any major expenses to FCD as a result of storm.
Told him of repeater and ALERT computers - passed info to Tom
Johnson next morning (early).
Briefed on expected Centennial Wash flow.
Centennial Wash about to spill over into CAP if it goes up
another 6 inches. Told him wash had probably peaked.
Rains last night causing a flow upper portion of New River (about
1600 cfs).
Centennial Wash flow should reach Old US 80 area around 5 PM.
Briefing - Wash may go to about 1000 cfs, another threat later on
- 4000 cfs?
Updated him on weather events - a little flow this morning, a little
more later on.
Updated 0715 AM briefing. 2000 cfs this morning?
Heavy rain on the way - mainly west side of town?
Water accumulating behind StoneRidge Dam
Already half to one inch into upper reaches of Sols Wash - more
to come.
Tiger Wash starting to flow.
Flow increasing in Centennial - now up to 2600 cfs upstream of
concerned area (I-10).
Briefed on happenings. Told him should be some runoff probably no big deal.
.50 to 1.25 inches next 1 to 2 hours many areas. Expect the worse,
but probably not quite as bad as few days ago.
Weather update. Worse about over?
Loss of water behind StoneRidge - why?
Briefed on runoff expected. Not sure but rain pattern did not
suggest much.
Some minor flows many washes - Agua Fria/Grand, New
River/Glendale, New River Dam and Hassayampa at Arlington.

18

10/27/00 8:30 PM
10/27/00 10:30 PM
10/28/00 12:07 AM

NWS - Phoenix
NWS - Phoenix
Wickenburg Police
Dispatch

10/28/00 2:30 AM

NWS - Phoenix

10/28/00 7:05 AM

MCDEM

10/28/00 7:30 AM
10/28/00 8:00 AM

La Paz County
Emergency
Management
La Paz Co. Public
Works

Briefed them on flows/runoff.
Updated them on flows/runoff.
Briefed them on weather for they're planning purposes, - see no
additional or new problems..
At Wenden Centennial up to about 3000 cfs - flow increasing
rather rapidly.
Told him Centennial Wash had risen from 5000 to 10,000 cfs
since 5:00 am, asked him to notify his contact in La Paz County.
Mary Dahl called the ALERT room for status of Centennial,
whether it might go up or down or stabilize, told her I did not
know at this point.
Called Tammy of Public Works at request of MCDEM, told her
how to get 5093 stage data via the web.

19

SUMMARY

A number of heavy thunderstorms dropped large amounts of rain in the Wickenburg area, lower
Hassayampa and upper Centennial watersheds on August 29th, 2000. These storms caused
flooding along several watercourses in northwestern Maricopa County and eastern La Paz
County, including Martinez Creek, Sols Wash and Centennial Wash. The storm produced
significant runoff events in the Wickenburg area and in the Centennial watershed with estimated
return periods of between 8 and 17 years.
The month of October featured a series of Pacific low-pressure frontal systems which tapped
tropical moisture in northern Mexico as they passed through the State, resulting in heavy
widespread rain with numerous embedded thunderstorms. Again, the Wickenburg and
Centennial areas were affected, along with Grass Wash, Tiger Wash, Jackrabbit Wash and much
of northern and central Maricopa County. On October 10th, flows in central Phoenix and
Scottsdale were generally around a 2-year return period. But the rains from this storms served to
wet many watersheds around the County, which added to the runoff potential for subsequent
storms. October 27th saw heavy runoff in the northern, central, western and northwestern
portions of the County. Centennial Wash experienced what is believed to be a 100-year event,
Sols Wash saw a 66-year return period event, Flying E Wash in Wickenburg around a 40, and
Hartman and Tiger Washes approximately 16-year events. Flows during the October 27th storm
were again heavy in the western and northwestern parts of the County. Jackrabbit Wash
experienced a 50-year flood, Hassayampa @ I-10 recorded a 70-year event, Casandro Wash in
Wickenburg managed a 40-year, and Sols and Tiger Washes each were treated to 10-year events.
Appendix E contains selected digital photos of flooding from around the County.

20

APPENDIX A
Selected Outlook and Message Products from the
Meteorological Services Program

21

Flood Control District of Maricopa County
Meteorological Services Program (MSP)

WEATHER OUTLOOK

Date & Time:
Forecaster:
Phone:

Monday, August 28, 2000 1:35 PM MST
Jim Perfrement
602-506-8701

SYNOPSIS:

A little rain this morning in spots, nothing really significant. But it shows how moist the atmosphere
has become - perhaps more moist than any other time this summer. But cloud cover and relatively
cool temperatures hurting the chances of significant rain this afternoon/tonight. Believe there will be
some storms but perhaps not much heavy rain. Kinda feel tomorrow afternoon or night may be the
biggy. And looking down the road - monsoon may end about Thursday (give or take a day), as very
dry air to move in and stay awhile.
At 1:15 PM there were light showers everywhere, though a minimum over MSP area. The strongest
storms were over far southwest Maricopa County and southeast of our area - roughly a line from east
of Globe down to the Tucson. Movement was generally toward the north or northwest 15 mph.

Forecast Zone
Palo Verde
Rainbow Valley
West Valley
Northwest Valley
Wickenburg
Lake Pleasant
New River/Cave Creek
Phoenix
Tempe Town Lake
Southeast Valley
Scottsdale
Lower Salt River Lakes
Superstition

Tonight / Tue A.M.
Chance of Rain (%)
40
40
40
40
40
50
50
40
40
50
50
50
60

Prime Time
5pm - 1am
5pm - 1am
6pm - 1am
6pm - 1am
5pm - 1am
5pm - 1am
Now - 1am
6pm - 1am
6pm - 1am
5pm - 1am
6pm - 1am
4pm - 1am
4pm - 1am

22

Maximum Prime
Time Amount (in.)
.60
.70
.60
.60
.60
.70
.80
.60
.60
.70
.70
.70
.80

Flood Control District of Maricopa County
Meteorological Services Program (MSP)

WEATHER OUTLOOK

Date & Time:
Forecaster:

Friday, October 20, 2000 1:30 PM MST
Waters

SYNOPSIS:
Quite pleasant outside right now, temperatures in the mid-80s with very few clouds. Look for a high today
around 87 with light winds and some gusts to 15 mph. Tonight will be clear and cool. Should be dry between
now and Saturday evening.
Starting Saturday night, we are expecting a Pacific storm which is now moving over San Francisco, to slide into
the MSP zones. This storm has reasonable moisture with it, and will pull in additional moisture from yesterday's
storm which remains over SE AZ and northern Mexico. This will combine to cause a significant rain event for
this time of year, possibly an inch on the deserts and 2 inches in the mountains. Luckily, the warm air that
caused embedded thunderstorms and lots of lightning yesterday will not be present, and we can expect a more
winter-like rain of long duration and low intensity. This storm could cause intermittent showers through Tuesday
morning.
If conditions warrant we will produce a forecast/products on Sunday.

Forecast Zone
Palo Verde
Rainbow Valley
West Valley
Northwest Valley
Wickenburg
Lake Pleasant
New River/Cave Creek
Phoenix
Tempe Town Lake
Southeast Valley
Scottsdale
Lower Salt River Lakes
Superstition

Tonight / Sat A.M.
Chance of Rain (%)

Prime Time

N
O
N
E

23

Maximum Prime
Time Amount (in.)

Flood Control District of Maricopa County
Meteorological Services Program (MSP)

WEATHER OUTLOOK

Date & Time:
Forecaster:

Saturday, October 21, 2000 1:10 PM MST
Jim Perfrement

SYNOPSIS:
Think wet - very wet. This outlook will also be a heads up, or flash flood watch, regarding expected weather
conditions. Storm action plans should be looked at - as the odds are good this storm will result in locally (at
least) runoff. Be prepared!
A few showers have already taken place over portions of the MSP area - all light. And at 12:45 PM radar
showed scattered light to moderate showers and thunderstorms developing over southwest Maricopa county from northwest of Gila Bend to east of Gila Bend. Movement was toward the northeast about 15 mph.
Although rain will be taking place this afternoon and evening I believe the main event will be from late tonight
through Sunday night. If the guidance is anywhere near correct some MSP areas should get an inch to 1.5
inches. And there will be additional rain, at times, lasting through Monday and possibly as long as Tuesday
morning. Again, be prepared.
It will also be very cool the next few days, with afternoon highs ranging from the upper 60s to middle 70s. And it
will be breezy.
I will be in the office Sunday (possibly late tonight if it gets nasty).

Forecast Zone
Palo Verde
Rainbow Valley
West Valley
Northwest Valley
Wickenburg
Lake Pleasant
New River/Cave Creek
Phoenix
Tempe Town Lake
Southeast Valley
Scottsdale
Lower Salt River Lakes
Superstition

Tonight / Sun A.M.
Chance of Rain (%)

A
B
O
U
T
100
%

Prime Time

Maximum Prime
Time Amount (in.)

2 AM

.25

T
O

TO

NOON
.50

24

Flood Control District of Maricopa County
Meteorological Services Program (MSP)

Message 1
Alert

Date & Time:
Forecaster:
Phone:

Saturday, October 21, 2000 11:40 PM MST
Jim Perfrement
602-506-8701

Comments:
Time to update everyone on weather events. As for this past evening - business was done by phone to areas
that received significant rain - resulted in flooding of washes/roads. It appears the hardest hit area was
Wickenburg, and areas to the west and north of Wickenburg. Rainfall was generally from 1 to 3 inches. At 11
PM there was a significant flow in the Hassayampa River moving south from Wickenburg that will probably
result in the closing of Patton Road in an hour or two(MCDOT give me a call for details).
Another area of concern was Rainbow Valley, as locally heavy rain caused Waterman Wash to flow. Overall,
there was a lot more rain than expected for the evening hours. And more is to come.
At 11:30 PM very little rain was being reported over the southern portion of the MSP area. But there were still
scattered light to moderate showers and thunderstorms over northern sections - but at most locations not as
much rain as earlier in the evening. And for the most part additional rain the next couple of hours will not be
sufficient to result in significant additional flooding - just retard the drying process.
But more rain is on the way - possibly a lot more rain. Radar shows activity developing over La Paz and Yuma
county - moving north and east. And numerical guidance suggests rains of well over an inch may fall later this
coming day - with additional amounts Sunday night and into Monday. So stay tuned.
I will be at the above phone number for the remainder of the night, and will update the weather picture as
additional information becomes available.
This message is not intended for public dissemination. Please pass this information along to
appropriate emergency response organizations (police, fire, transportation, etc.) you support. Also,
please take appropriate actions to prepare for possible flooding.

25

Flood Control District of Maricopa County
Meteorological Services Program (MSP)

WEATHER OUTLOOK

Date & Time:
Forecaster:

Thursday, October 26, 2000 1:00 PM MST
Jim Perfrement

SYNOPSIS:
More weather disturbances on the way - main periods appear to be Friday (probably afternoon) through Friday
night, then Monday, and then again late in the week. For now will only discuss the next two. The atmosphere
remains rather moist from the storm this past weekend - more importantly the ground is also very moist. And
due to saturated soil conditions additional rain will mostly become runoff. In other words - a situation than could
lead to additional flooding.
On a more positive note this next disturbance should not linger over our area like the past one did. It should be
east of the MSP area by late Saturday. The big question is - how much rain will fall until then? Right now I would
place the average storm total in the .50 to .75 inch bracket, enough to cause many washes and creeks to once
again flow - though overall not to levels of past storm. But there could be higher rain accumulations, over an
inch, especially over the higher terrain of the MSP area - so once again stand by.
The weather disturbance forecast to arrive Sunday night and/or Monday is forecast to track a little farther north.
If so the main impact (heavy rain) should be north of the MSP area, though very possibly some showers our
area.
Temperatures will remain below normal through the weekend, and it may become locally very breezy at times.

Forecast Zone
Palo Verde
Rainbow Valley
West Valley
Northwest Valley
Wickenburg
Lake Pleasant
New River/Cave Creek
Phoenix
Tempe Town Lake
Southeast Valley
Scottsdale
Lower Salt River Lakes
Superstition

Tonight / Fri A.M.
Chance of Rain (%)
60
"
"
"
"
"
"
"
"
"
"
"
"

Prime Time
3am - noon
"
"
"
"
"
"
"
"
"
"
"
"

26

Maximum Prime
Time Amount (in.)
.40
"
"
"
"
"
"
"
"
"
"
"
"

Flood Control District of Maricopa County
Meteorological Services Program (MSP)

Message 3
Flash Flood
Warning
Date & Time:
Forecaster:
Phone:

Friday, October 27, 2000 12:55 PM MST
Jim Perfrement
602-506-8701
Forecast Zone

Palo Verde
Rainbow Valley
West Valley
Northwest Valley
Wickenburg
Lake Pleasant
New Rvr/Cave Creek

X

Phoenix
Tempe Town Lake
Southeast Valley
Scottsdale
Lower Salt River Lakes
Superstition

This warning is valid Now to 5:00 PM MST.

Comments:
Strong thunderstorms have moved into the Wickenburg area - rain accumulation rate of an inch an hour some
areas. As ground is saturated all this will result in runoff. At 12:45 the heaviest rain was over southern portions
of the town, but will spread through most areas the next half to one hour.
Take precautions.
Note: A Flash Flood Warning is issued when it appears flooding is imminent - usually within 30 minutes
of the statement.
This message is not intended for public dissemination.
Please expedite this information to affected emergency response organizations (police, fire,
transportation, etc.) within your area.
Also, please take appropriate actions to prepare for possible flooding.
Further information will be provided as it becomes available.

27

Flood Control District of Maricopa County
Meteorological Services Program (MSP)

Message 3
Flash Flood
Warning
Date & Time:
Forecaster:
Phone:

Friday, October 27, 2000 1:50 PM MST
Jim Perfrement
602-506-8701
Forecast Zone

Palo Verde
Rainbow Valley
West Valley
Northwest Valley
Wickenburg
Lake Pleasant
New Rvr/Cave Creek

X
X
X

Phoenix
Tempe Town Lake
Southeast Valley
Scottsdale
Lower Salt River Lakes
Superstition

X
X

X

This warning is valid Now to 4:00 PM MST.

Comments:
Updated to included Phoenix, Tempe Town Lake and Rainbow Valley zones. Sorry about that.
Strong thunderstorms have moved into the warning area. Movement was toward the northeast about 30 mph.
Rain accumulation from this band of storms was locally over an inch an hour. This will result in flash flooding.
Take precautions.
Note: A Flash Flood Warning is issued when it appears flooding is imminent - usually within 30 minutes
of the statement.
This message is not intended for public dissemination.
Please expedite this information to affected emergency response organizations (police, fire,
transportation, etc.) within your area.
Also, please take appropriate actions to prepare for possible flooding.
Further information will be provided as it becomes available.
28

APPENDIX B
Point Rainfall Maps and
Isohyetal Rainfall Coverage Maps
from FCD Automated Gage Data

29

August 29th, 2000

30

October 10th, 2000

31

October 21st - 23rd, 2000

32

October 27th, 2000

33

APPENDIX C
NEXRAD Radar Reflectivity Images
From Phoenix WFO

Storm-Total Precipitation Map for 08/26/00 11:07 through 08/29/00 13:00 MST

34

1-hour Precipitation Map ending 10/21/00 at 18:00 MST

Storm-Total Precipitation Map for 10/20/00 14:47 through 10/22/00 00:00 MST
35

3-hour Precipitation Map ending 10/27/00 at 12:00 MST

Storm-Total Precipitation Map for 10/26/00 17:15 through 10/27/00 17:00 MST
36

APPENDIX D
Depth/Duration/Frequency Plots and Histograms
for Seven Selected Stations

Agua Fria
Watershed

Hassayampa
Watershed

Centennial
Watershed

37

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39

40

41

42

43

44

45

46

47

APPENDIX E
Selected Digital Photos

Big No-No on Centennial Wash @ Eagle Eye Road near Aguila, 10/23/2000

Centennial Wash @ Harquahala Valley Road - 10/23/2000

48

Centennial Wash @ Salome Road - 10/23/2000

FCD crew taking a flow measurement on the US 60 Bridge over the Hassayampa River

49

High-water mark, Jackrabbit Wash near the intersection of Wickenburg and Vulture
Mine Roads, caused by the flood of 10/27/2000. The gage was installed on the 31st
and not in service during the flood.

Martinez Creek at Scenic Loop Rd., Aug. 29, 2000 at 12:10, note large standing waves
50

Powderhouse Wash at Constellation Road, Aug. 29, 2000 at 11:35

Sols Wash at Vulture Mine Road, view to south, Aug. 29, 2000 at 11:50
51