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Canal Irrigation Systems on the Gila River Indian Reservation

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					                                                                                         Canal Irrigation Systems on the Gila River Indian Reservation
                                                                                                                                                Findings from the SFPP East Line Expansion Project
                                                                                                                                                                         John C. Ravesloot1 and M. Kyle Woodson2


The Prehistoric Riverbend Canal System                                                                                                                                                                                                                                          Historic Canal Irrigation in the Gila Crossing District
 Archaeological excavations conducted on the Gila River                    Canals as Artifact Trails                                            Canal Characteristics                                Dune Canals                                                                  The Gila Crossing District is located along the Gila River at the western end of
                                                                                                                                                                                                                                                                                                                                                                                   Cleaning Co-op Ditch, 1917
 Indian Community for the SFPP East Line Expansion                                                                                                                                                                                                                                the Gila River Indian Reservation. Although the Hohokam farmed with canals in                    Cleaning Co-op Ditch, 1917
 Project resulted in the discovery of 40 prehistoric                       Eighteen canal alignments are manifested on the                      A total of 38 subsurface canals were excavated       Nine of the 10 canals at GR-893 are buried under a dune. The
                                                                                                                                                                                                     Nine of the 10 canals at GR-893 are buried under a dune. The                 this area, neither the Pimas nor Maricopas practiced canal irrigation there prior to
 Hohokam canals. The canals were documented at three                       ground surface as linear artifact scatters that extend               including 11 canals at GR-893, 6 canals at GR-       canals are not evident on the ground surface as linear artifact
                                                                                                                                                                                                     canals are not evident on the ground surface as linear artifact              1873. The Maricopas settled in the district in the early 1800s, and farmed in the
 sites (GR-893, GR-894, GR-895) along the left bank of                     from the edge of the river terrace to the west.                      894, and 21 canals at GR-895. Two other canals       scatters because the dune has not been deflated to a significant
                                                                                                                                                                                                     scatters because the dune has not been deflated to a significant             floodplain where crops were watered by floodwaters and seepage. Further
 the Gila River. The canals occur on the Holocene                          These linear scatters were tracked on foot for                       were recorded only as surface linear artifact        degree. The canals are uniformly shallow (less than 1.8 ft deep)
                                                                                                                                                                                                     degree. The canals are uniformly shallow (less than 1.8 ft deep)             upstream, the Pimas irrigated expansive farmlands with canals, which they had
 terrace between Pima Butte and the confluence of the                      distances of 0.3 mi to 0.6 mi, and most of them                      scatters. The subsurface canals included 7 main      and narrow (most are less than 1 yd wide), and all are oriented
                                                                                                                                                                                                     and narrow (most are less than 1 yd wide), and all are oriented              been doing since at least 1744. By around 1840, the Maricopas first began
 Santa Cruz and Gila rivers in an area of the middle Gila                  extend further than this. The scatters occur in                      canals, 14 distribution canals, and 14 lateral       east–west. These canals appear to have been used just prior to
                                                                                                                                                                                                     east–west. These canals appear to have been used just prior to               farming with canals near the Pima villages.
 Valley known as “Santa Cruz Island.” This is a major                      deflated portions of the Holocene terrace, where the                 canals. Feature 10 at GR-894 is the largest main     and possibly during an environmental change that resulted in the
                                                                                                                                                                                                     and possibly during an environmental change that resulted in the
 finding for our understanding of Hohokam canal                            canals and their contents have eroded onto the now                   canal with a cross-sectional area of 4.77 m2 (see    deposition of dunes in the Santa Cruz Island area. The area
                                                                                                                                                                                                     deposition of dunes in the Santa Cruz Island area. The area
 systems. Prior to this project, no prehistoric canals had                 flat ground surface. The scatters vary in width from                 profile below). This canal and two other main        may have witnessed intermittent wet and dry periods, with the
                                                                                                                                                                                                     may have witnessed intermittent wet and dry periods, with the                In the late 1800s, many Pimas and Maricopas abandoned their fields and villages
 been confidently identified on Santa Cruz Island. This                    about 10 yds to 20 yds. This area along the Middle                   canals contain smaller channels within their upper   dunes being deposited in the dry periods. These canals may
                                                                                                                                                                                                     dunes being deposited in the dry periods. These canals may                   upstream of the Gila Crossing District due to increased water shortages and other
 canal complex has been named the Riverbend canal                          Gila River may be one of last places that prehistoric                portions which may be lateral canals or "echo"       have been abandoned at the onset of a dry period and
                                                                                                                                                                                                     have been abandoned at the onset of a dry period and                         problems. Most of the Maricopas moved to the Salt River Valley or the far western
 system, as it headed near one of most pronounced                          canals can be seen on the surface as artifact                        canals. These represent later attempts to re-use     subsequently were covered by windblown sediments during dune
                                                                                                                                                                                                     subsequently were covered by windblown sediments during dune                 end of the reservation. Large groups of Pimas migrated to the Gila Crossing
 bends in the middle Gila River.                                           “trails.”                                                            the main canal at a smaller scale.                   formation.
                                                                                                                                                                                                     formation.                                                                   District where they found a more permanent and reliable water supply.

                                                                                                             Aerial Photo of Santa
                                                                                                               Aerial Photo of Santa
                                                                                                             Cruz Island showing              Trench exposure of main canal
                                                                                                                                               Trench exposure of main canal
                                                                                                               Cruz Island showing
                                                                                                             linear artifact scatters         Feature 77at GR-895, Locus 33
                                                                                                                                               Feature at GR-895, Locus
                                                                                                               linear artifact scatters
                                           Riverbend Canal System:                                                                                                                                                                                                                                                                                                                                           Hoover Ditch
                                            Riverbend Canal System:
                                           Sequence of Development
                                            Sequence of Development                                                                                                                                                                                                               The Hoover and Hollen Ditches
                                                                                                                                                                                                                                                                                  The Pimas built six canals in the Gila Crossing District
                                                                                                                                                                                                                                                                                  The Pimas built six canals in the Gila Crossing District
                                                                                                                                                                                                                                                                                  between 1873 and 1903. The first canal was the Hoover
                                                                                                                                                                                                                                                                                  between 1873 and 1903. The first canal was the Hoover
                                                                                                                                                                                                                                                   Exposure of canals buried
                                                                                                                                                                                                                                                    Exposure of canals buried     Ditch built in 1873. The John Thomas Ditch and the
                                                                                                                                                                                                                                                                                  Ditch built in 1873. The John Thomas Ditch and the
                                                                                                                                                                                                                                                   under dune at GR-893
                                                                                                                                                                                                                                                    under dune at GR-893          Hollen Ditch were built in 1876/1877, followed by the
                                                                                                                                                                                                                                                                                  Hollen Ditch were built in 1876/1877, followed by the
                                                                                                                                                                                                                                                                                  Joseph Head Canal in 1886, the Cooperative Canal in
                                                                                                                                                                                                                                                                                  Joseph Head Canal in 1886, the Cooperative Canal in
                                                                                                                                                                                                                                                                                                                                                                                                     Hollen Ditch
                                                                                                                                                                                                                                                                                  1900, and the Oscar Walker Canal in 1903.
                                                                                                                                                                                                                                                                                  1900, and the Oscar Walker Canal in 1903.                                                                          (aka Santa Cruz Ditch)
                                                                                                                                                                                                                                                                                  Segments of the Hoover Ditch and the Hollen Ditch were
                                                                                                                                                                                                                                                                                  Segments of the Hoover Ditch and the Hollen Ditch were
                                                                        Linear artifact scatters at GR-894
                                                                        Linear artifact scatters at GR-894                                                                                                                                                                        excavated during the East Line Expansion Project. As
                                                                                                                                                                                                                                                                                  excavated during the East Line Expansion Project. As                                                                       C. H. Southworth (1914)
                                                                        marking alignments of prehistoric
                                                                        marking alignments of prehistoric                                                                                                                                                                         mapped by C. H. Southworth in 1914, the Hoover Ditch
                                                                                                                                                                                                                                                                                  mapped by C. H. Southworth in 1914, the Hoover Ditch                                                                       C. H. Southworth (1914)
                                                                        main and lateral canals                                                                                                                                                                                   was 7.08 miles long and it irrigated an area of 954 acres.
                                                                                                                                                                                                                                                                                  was 7.08 miles long and it irrigated an area of 954 acres.                                                                 Gila River Survey
                                                                                                                                                                                                                                                                                                                                                                                                             Gila River Survey
                                                                        main and lateral canals
                                                                                                                                              Profile of largest main                                                                                                             A post-1914 extension of this ditch crosses the project
                                                                                                                                                                                                                                                                                  A post-1914 extension of this ditch crosses the project
                                                                                                                                               Profile of largest main
                                                                                                                                              canal in system
                                                                                                                                               canal in system                 “Echo” Channel
                                                                                                                                                                                                     A Different Kind of Canal System                                             area, and was documented as GR-1440.
                                                                                                                                                                                                                                                                                  area, and was documented as GR-1440.
                                                                                                                                                                                “Echo” Channel                                                                                    The Hollen Ditch (later renamed the Santa Cruz Ditch),
                                                                                                                                                                                                     The Riverbend canal system exhibits some differences from
                                                                                                                                                                                                      The Riverbend canal system exhibits some differences from                   The Hollen Ditch (later renamed the Santa Cruz Ditch),
                                                                                                                                                                                                     other Hohokam canal systems on the middle Gila River. First,                 was built in 1877, and has the most easterly heading of
                                                                                                                                                                                                                                                                                  was built in 1877, and has the most easterly heading of
                                                                                                                                                                                                      other Hohokam canal systems on the middle Gila River. First,                                                                                                                          Abandoned Hoover Ditch,
                                                                                                                                                                                                                                                                                                                                                                                             Abandoned Hoover Ditch,
                                                                                                                                                                                                     more than one main canal was operated simultaneously during                  the canals in the Gila Crossing District. As mapped by
                                                                                                                                                                                                                                                                                  the canals in the Gila Crossing District. As mapped by
                                                                                                                                                                                                      more than one main canal was operated simultaneously during                                                                                                                           in the Fall 2005
                                                                                                                                                                                                     most of its use. The dramatic northward bend in the Gila River in            Southworth in 1914, the Hollen Ditch was 4.9 miles long
                                                                                                                                                                                                                                                                                  Southworth in 1914, the Hollen Ditch was 4.9 miles long                                                    in the Fall 2005
                                                                                                                                                                                                      most of its use. The dramatic northward bend in the Gila River in
                                                                                                                                                                                                     this area probably allowed irrigators to use multiple headgates              and it irrigated an area of 660 acres. A portion of the
                                                                                                                                                                                                                                                                                  and it irrigated an area of 660 acres. A portion of the
 The Riverbend canal system headed on the Gila River                                                                                                                                                  this area probably allowed irrigators to use multiple headgates
                                                                                                                                                                                                     and main canals to farm land on Santa Cruz Island. Also, the                 upper segment of this ditch crosses the project area, and
                                                                                                                                                                                                                                                                                  upper segment of this ditch crosses the project area, and
 near Pima Butte and extended between 5.6 and 7.5                                                                                                                                                     and main canals to farm land on Santa Cruz Island. Also, the
                                                                                                                                                                                                     canals do not appear to serve any major villages on the scale of             was documented as GR-1439.
                                                                                                                                                                                                                                                                                  was documented as GR-1439.
 miles long. The system initially was used in the early                                                                                                                                               canals do not appear to serve any major villages on the scale of
 Colonial period, around A.D. 750. By the Sedentary                                                                                                                                                  Snaketown or Hidden Ruin. One reason could be that Santa
                                                                                                                                                                                                      Snaketown or Hidden Ruin. One reason could be that Santa
 period (ca. A.D. 950), the canals in GR-894 appear to                                                                                                                                               Cruz Island was farmed by Hohokam groups that did not
                                                                                                                                                                                                      Cruz Island was farmed by Hohokam groups that did not
 have been abandoned, perhaps due to excessive                                                                                                                                                       establish permanent or long-lived settlements. GR-893 may
                                                                                                                                                                                                      establish permanent or long-lived settlements. GR-893 may                   Canal Models
 salinization of soils along the canals, or possibly due to                                                                                                                                          have been occupied on a seasonal basis by different groups of
                                                                                                                                                                                                      have been occupied on a seasonal basis by different groups of
 problems presented by steeper canal gradients in that                                                                                                                                               people who traveled from another "base" settlement to farm on
                                                                                                                                                                                                      people who traveled from another "base" settlement to farm on               The archaeological and historical documentation of these
                                                                                                                                                                                                                                                                                  The archaeological and historical documentation of these
 area. Irrigation shifted more intensively to the northern                                                                                                                                           Santa Cruz Island. A primary candidate for such a base is Hidden
                                                                                                                                                                                                      Santa Cruz Island. A primary candidate for such a base is Hidden            two canals provides an opportunity to construct a model of
                                                                                                                                                                                                                                                                                  two canals provides an opportunity to construct a model of                             GR-1439 Hollen (Santa Cruz) Ditch
                                                                                                                                                                                                                                                                                                                                                                             Trench 1, Southeast Wall
 part of Santa Cruz Island. During the Classic period,                                                                                                                                               Ruin, a large pre-Classic period village with two ballcourts
                                                                                                                                                                                                      Ruin, a large pre-Classic period village with two ballcourts                canal dynamics. Historic records on irrigated acreage,
                                                                                                                                                                                                                                                                                  canal dynamics. Historic records on irrigated acreage,                                     Feature 1 Profile (Canal)

 all but one of the canals in GR-893 probably were                                                                                                                                                   located less than 2 miles northeast on the opposite side of the
                                                                                                                                                                                                      located less than 2 miles northeast on the opposite side of the             crop yields, canal dimensions, and population for the
                                                                                                                                                                                                                                                                                  crop yields, canal dimensions, and population for the
 abandoned, as the northern part of Santa Cruz Island                                                                                                                                                Gila River (see Figure 2 above). Hidden Ruin did not have
                                                                                                                                                                                                      Gila River (see Figure 2 above). Hidden Ruin did not have                   Hoover and Santa Cruz ditches will provide valuable
                                                                                                                                                                                                                                                                                  Hoover and Santa Cruz ditches will provide valuable
 became the primary and likely the only focus of                      This is the first in a two-poster series presenting results of the SFPP East Line Expansion Project.                           access to expansive irrigable lands on the north side of river, and
                                                                                                                                                                                                      access to expansive irrigable lands on the north side of river, and         historic analogs for studying prehistoric Hohokam canals.
                                                                                                                                                                                                                                                                                  historic analogs for studying prehistoric Hohokam canals.
 irrigation. The entire canal system was abandoned by                                                                                                                                                its inhabitants may have used additional farmland on Santa Cruz
                                                                                                                                                                                                      its inhabitants may have used additional farmland on Santa Cruz             An important conclusion from such modeling is that
                                                                                                                                                                                                                                                                                  An important conclusion from such modeling is that
 the end of the Classic period (ca. A.D. 1450). The                                                                                                                                                  Island. Such practice of cultivating land on the opposite side of
                                                                                                                                                                                                      Island. Such practice of cultivating land on the opposite side of           calculations of hydraulic parameters using the maximum
                                                                                                                                                                                                                                                                                  calculations of hydraulic parameters using the maximum
 system could have irrigated between 2,471–3,706                                                                                                                                                     the river from the village is documented for the Pimas during the
                                                                                                                                                                                                      the river from the village is documented for the Pimas during the           dimensions of prehistoric canals will result in a dramatic
                                                                                                                                                                                                                                                                                  dimensions of prehistoric canals will result in a dramatic
 acres of land.
                                                                                1   William Self                                          2   Gila River Indian Community,                           1800s.
                                                                                                                                                                                                      1800s.                                                                      overestimation of canal discharge and irrigable acreage.
                                                                                                                                                                                                                                                                                  overestimation of canal discharge and irrigable acreage.
                                                                                    Associates, Inc.                                          Cultural Resource Management Program

				
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