Prehistoric Bajada Hanging Canals of Southeastern Arizona

Prehistoric Bajada Hanging Canals of Southeastern Arizona

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Description: A summary of recent spectacular prehistoric "hanging" canal discoveries in the Safford Basin of Southeastern Arizona. The engineering and energy efficiency of these is utterly mind boggling. Additional resources at https://www.tinaja.com/tinsamp1.shtml .

 
Author: Don Lancaster and Dr. James Neely (Fellow) | Visits: 3143 | Page Views: 3669
Domain:  Green Tech Category: Wind/Water/Geo Subcategory: Big Picture 
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Contents:
Prehistoric Bajada "Hanging Canals"
of Southeastern Arizona
Don Lancaster and Dr. James Neely
Synergetics, Box 809, Thatcher, AZ 85552
copyright c2014 pub 2/14 as GuruGram #123
http://www.tinaja.com
don@tinaja.com and neelyja@att.net
(928) 428-4073 and (575) 686-0098

The presence of irrigation and domestic water supply canals in the bajada of the
Pinaleno Mountains of Safford Basin expands the knowledge of prehistoric water
management and agricultural intensification in the American Southwest.

In contrast to the lowland riverine floodplain canals, such as those found in the
Hohokam culture in the Phoenix Basin, an extensive network of canal systems
exists in the undulating piedmont landscape of southeastern Arizona. These canal
systems are seen as an adaptive technology to mitigate the arid topography and
climate, and greatly expand the settlement and agricultural potential of the area.

Scope and Extent
This apparently unique series of late classic prehistoric mountain stream fed water
management structures have been recently rediscovered in the Safford Basin of
Arizona’s upper Gila Valley. At least twenty eight hanging canal systems or canal
fragments have been identified to date.
The longest canals are about 9.5 kilometers (ca. 6 miles) and the total length of
all systems is currently estimated to exceed 80 kilometers (ca. 50 miles) While
a few of these canals may date as early as ca. A.D. 800, the vast majority appear
to have originated after ca. A.D. 1250 and persisted until ca. A.D. 1450.

Reasons for the Hanging Structures
Portions of these canal systems are literally "hung" on the edges of steep sided,
gently sloping Mesas formed from remnant Quaternary age Bajadas. The canals
appear unique from those found in the vicinity of Phoenix and elsewhere in the
Southwest in that they obtained their water from mountain drainages fed by
runoff, springs, and Artesian sources, rather than from rivers.
They are also unusual in that they traverse the vertically undulating to severely
erratic uplands of Basin and Range topography rather than being restricted to a
nearly level riverine floodplain. At places, the hanging structures are as much as
60 meters above their adjacent drainage basins.
— 123 . 1 —

( insert mary2.jpg as watermark after distilling )
( link full image as http://www.tinaja.com/canal/mary2.jpg )

Hanging canal (middleground) flowing from right to left along the
west side of the long and narrow mesa landform near the mouth of
Marijilda Canyon. At this point, the canal is about 50 meters above
the western basin. The canal coursing upslope illusion is discernable.

It appears the highest feasible locations on mesas were carefully selected for canal
routes. It also seems clear that extreme energy efficiency was a major goal during
the canal construction. Two credible reasons for these unique hanging routes is
that their slope could be made largely independent of the surrounding terrain.
And that much of the construction effort could be efficiently made across, rather
than along the canal routes. Thus minimizing any energy loss or water robbing
cuts and fills.
Canal cross-sections vary from 0.30 to one meter, with atypical examples up to
two meters in width, and 20 to 40 centimeters in depth. Their use seems to be
primarily long distance water delivery to fields, but a few of these canals are
bordered by prehistoric habitation sites and well-defined agricultural fields.

Proof of Age
When assisted by historic rebuilds, several reaches of the canals still flow to this
day. Portions of most of the systems remain largely pristine, and many are now
currently filled with fine grained sediments. These systems are located mostly on
Arizona State and Coronado National Forest lands that still remain undeveloped.
While often of difficult access, major canal portions are usually easily traced. There
are few access roads and fewer mesa top trails.
— 123 . 2 —

( insert safcan1.jpg as watermark after distilling )
( link full image as
http://www.tinaja.com/canal/safcan1.jpg )

Locations of the bajada sourced hanging canals recorded to date

While the canals have been dated mostly by stratigraphy and association, other
evidence of age does include: Being run over by roads, SCS dams, and even
cemeteries roughshod without any accomodation; uniform patina, lichens, and
caliche; mature trees, cacti, and shrubs mid-channel; extreme purposefullness and
well directed energy efficiency; and a lack of apparent use of pioneer or CCC tools
except in places of obvious refurb or adaptation.

Population Density
Surveys in Lefthand Canyon and Marijilda Canyon have recorded a rather heavy
population concentrated along the canals, but the sites are nearly all small and
scattered. Survey along many of the other canals recorded only a few small sites.
These findings provide evidence in the form of agricultural intensification and
settlement that points to a socio-political organization based on the collaboration
and collective action of small corporate groups rather than a more complex social
stratification and socio-political structure. Such findings parallel those reported in
the Hohokam area.

Trading Partners
Ceramics and house remains from contemporary habitation sites indicate both
trading activity and residence by several of the prehistoric cultural groups of the
Southwest. Besides the Mimbres, Mogollon, Salado, and Ancient Pueblo Peoples,
the Hohokam master canal builders of the Phoenix area are clearly included.
— 123 . 3 —

( insert rob2.jpg as watermark after distilling )
( link full image as
http://www.tinaja.com/canal/rob2.jpg )

Looking down canal at the narrow, nearly completely filled channel
of the Robinson Canal as it routes along the steep side of a mesa
on its way to fields on Robinson Flat. Note the illusion of the canal
coursing upslope.

While it is likely that some of the canals were engineered and constructed by the
local inhabitants of the Safford Basin, the Hohokam presence does suggest that
Hohokam migrants may have at least in part assisted in engineering the later
more sophisticated canal constructions.

Associated Water Management Structures
The hanging canals are found in an area where other older and contemporaneous
water management schemes are also present. These include conventional lowland
riverine canals, extensive dry farming terraced and grid fields, numerous check
dams, some of which are aproned, single room field houses, and grouped arrays
of mulch rings and rock piles.
No survey instruments are known to survive, but it is possible that pilot extensions
of the canals themselves served as static water levels.
The construction effort is variously believed to be fifty man years or more. Some
portions of the system give a rather strong "water flowing uphill" illusion, owing
to the controlled gentle slopes and the nature of the adjacent terrain.
Additional associated structures include a long aqueduct crossing a saddle, a deep
and long cut, and an upcanyon routed "counterflow" canal segment.
— 123 . 4 —

References
Murphy, Everett, J. and Neely, James A, Prehistoric Gila River Canals of the
Safford Basin , Proceedings of the AAC Fall 2005 Meeting, edited by D. E.
Purcell, 2008.
Neely, James A., Prehistoric Agricultural and Settlement Systems in Lefthand
Canyon, Papers of the Archaeological Society of New Mexico, #31, 2005.
Hunt, R.C. Plausible Ethonographic Analogies for the Social Organization of the
Hohokam Canal Irrigation, American Antiquity, 70:433-456.
Doolittle, William E. and Neely, James A, The Safford Valley Grids: Prehistoric
Cultivation in the Southern Arizona Desert, University of Arizona Press, 2004.
Wagner, Dennis, Arizona hanging canals whet appetite for ancient history,
USA Today, February 24, 2013

Further reading
Allhands, Joanna, Hanging canals’ lesson: We haven’t changed much,
AZCentral.com Feb 27, 2013.
Lancaster, Don. Prehistoric Hanging Canals of the Safford Basin 2013.
Neely, James A. and Lancaster, Don. A Prehistoric Hanging Canal Lecture 2013.
Neely, James A. and Lancaster, Don, The Bajada Canals of the Safford Basin:
Small Small Corporate Group Collaboration in Southeastern Arizon, Glyphs
Volume 64, Numbers 3 & 4, 2013. Combined paper also here.
Wagner, Dennis, Mysterious Canals Believed to Come from Ancient Civilization,
The Arizona Republic, Feb 24,2013

Ongoing Studies
A collection of related hanging canal papers: www.tinaja.com/tinsamp1
The latest hanging canal developments: www.tinaja.com/whtnu14.shtml
Tours and personal research opportunities: don@tinaja.com

— 123 . 5 —