Tucson’s Waterways
Unit 1 Fitting a local arroyo into the Tucson Basin
Through field studies, hands-on experiments, and exercises using maps, photos and
discharge data from the Tucson Basin, students explore how water flows through
Tucson
Unit 1 goals
- Map skills (elevation, scale, Tucson geography).
- Drainage networks and basins concepts and practice.
- Data analysis and graphical interpretation: precipitation and discharge.
- Connect local water and development phenomena in DVHS to those in the
greater Tucson Basin.
- Field studies, linking observations to process.
- Writing skills.
- PowerPoint, Excel, Web, GPS skills.
- Scientific method.
- Organizational skills (develop portfolio over the whole project).
Arroyo Guide
Students prepare a guide to the DVHS arroyo using information they gather from their
own fieldwork and from the other Tucson waterways activities completed. Each group is
responsible for writing an arroyo guide, with group members becoming specialists on
different features of the arroyo: vegetation, water flow, sediment and shape. All arroyo
guides will contain descriptions of the following: the four arroyo features, the arroyo’s
role in the rest of the Tucson surface water system and changes in the gully through
time. The guides can be posted on the web, turned into posters, made into pamphlets
etc….
Activity 1 Getting oriented – An introduction to the Tucson Basin and map reading
Students use 1 x 2  (1:250,000) maps of the Tucson and Nogales regions to gain
familiarity with map coordinates, contour lines, map scale and Tucson geography.
Activity 2 Investigating how water moves through Tucson
Students use aerial photographs and overlays of the Santa Cruz River Basin to identify
drainage basins, rank channels (by catchment area, size and vegetation), calculate
gradient and determine the direction of water flow.
Assessment 1
Exercise that requires students to find locations and elevations on map, convert map
distances to actual distances and calculate gradient.
Activity 3 Data Diving
Students use precipitation and stream gage data from the Santa Cruz River to determine
the relationship between precipitation, discharge and position along a channel profile.
Each student in a group is responsible for plotting and analyzing data from one stream
gage along the Santa Cruz. Each student creates a channel profile that includes all
gaging stations and the group compares results from each gaging station.
Assessment 2
Students review surface water concepts and map skills. To be done individually within
one time period. Students need not know any facts going into this exercise, but need to
be comfortable with the mapping and surface water concepts. The exercise will ask
students to locate coordinates on a map, find the distances between points, calculate
gradient, identify the direction of water flow, outline a specific drainage basin, and predict
the relative difference in discharge between two points along a channel.
Activity 4 Stream tables
Students build stream tables and explore the effects of slope and discharge on channel
shape, water speed and bank stability. This exercise emphasizes hypothesis testing
and requires students to review their stream table experiments in light of the scientific
method.
Activity 5 DVHS campus through time
Students put their high school on the map to understand how the wash behind campus
fits into the greater Tucson drainage network. Students investigate changes in the wash
and their campus over the past 50 years by studying 6 aerial photographs spaced at 10year intervals.
Parts of this activity can be used as a pre- and post-assessment.
Unit 2 The Santa Cruz, Tucson’s changing river
Unit 2 goals Students will:
- Gain familiarity with the geography and history of the Santa Cruz River.
- Recognize the dynamic change in Tucson over the last 100 year and the things
that drive it.
- Apply field and map skills learned in Unit 1.
- Start to develop a personal identification with some aspect of change in Tucson.
- Research a current (environmental/development) issue and develop a plan to
effect change in a way they see fit.
Activity 1 Same place different time
Students examine time-lapsed photo sets of Silver Lake, the Santa Cruz and downtown
Tucson. They mark the similarities and differences, and suggest possible explanations
for the differences.
Activity 2 The Santa Cruz flow
Students examine discharge data from 4 gaging stations on the Santa Cruz River
(Nogales to Marana) and explore how the flow changes over its course. Students
develop possible explanations for these changes and formulate ideas for how these
changes would be evident at each gaging station. Students plot the gaging stations on
the large-scale maps and draw channel profiles.
Activity 3 Santa Cruz field investigation
On separate trips, groups of students from the class visit the four gaging stations along
the Santa Cruz, collecting data on the vegetation, channel shape, type of sediment and
development. Each student writes a report describing his/her observations of the Santa
Cruz gaging station location that he/she visited. After all of the stations have been
visited, the students present their observations to the class and compare their findings
between stations, matching them to the expected differences from Activity 2.
Activity 4 Personal interviews
Students interview a family member or friend who has lived in Tucson over 50 years
about change in Tucson, with specific attention to water and development. The student
repeats the interview process with someone who lives in Tucson <20 years and then
answers his/her own interview questions about change.
Activity 5 Santa Cruz and Tucson timeline
Students use information that they have assembled in addition to information from a fact
sheet to create a time line of Tucson and the Santa Cruz over the past century. The
time line will include photographs, graphed data, facts about the development of Tucson,
personal information about the memories and events in their family’s history (with
respect to Tucson).
Activity 6 Research Project
Students pick a specific development issue in Tucson and in a paper/presentation define
the issue and present a way to address it. Students will do some research on the project
but will rely on much of the information that they gather over the course of the 2 units.
The project uses a structured format to develop an argument by defining an issue,
presenting the facts (past, present and future), and proposing a solution.