Rangeland Restoration Research
The impact of rock check dams in southern Arizona - photo and publication archive
Project Overview
Rock check dams are used throughout the world to mitigate erosion problems on degraded lands. Small rock dams have been used for centuries to alter runoff and sediment. Today, rock check dams are being used in rangeland restoration projects throughout the southwestern US.
Rocks placed across small channels causes sediment to deposit and create conditions for vegetation to establish and grow
These low-tech, non-engineered structures are commonly constructed in eroding channels where they cause sediment to deposit. The sediment stores moisture and creates conditions for the germination and growth of vegetation. Vegetation then causes more sediment to deposit and a feedback loop is created whereby channels are healed and vegetation is restored.
Santa Rita Experimental Range Watersheds 5 and 6
In 2008, a research project was initiated by scientists at the ARS - Southwest Watershed Research Center to quantify the impacts of rock check dams on runoff, sediment, and channel morphology. Thirty-seven porous rock structures were built on two small instrumented watersheds the Santa Rita Experimental Range in southern Arizona, USA. The watersheds are located on an alluvial fan at the base of the Santa Rita Mountains.
Watershed 5 Check Dam 2, November 2009 (left) and December 2020 (right)
Watershed 5 Check Dam 9, November 2009 (left) and December 2020 (right)
Watershed 5 Check Dam 11, November 2009 (left) and December 2020 (right)
Watershed 6 Check Dam 28, November 2009 (left) and December 2020 (right)
Watershed 6 Check Dam 30, November 2009 (left) and December 2020 (right)
Santa Rita supercritical runoff measuring flume
Each watershed is equipped with a rain gauge, supercritical flow flume, and sediment sampler. Thirty-five years of historical rainfall and runoff, and sediment data are available to compare with data collected after check dam construction.
Please see the project publications for detailed research results and data.
Channel profiles measured in 2008 and 2018 showing check dam induced gradient changes
Post-construction measurements of channel geometry and longitudinal channel profiles are being compared with pre-construction measurements to characterize the impact of check dams on sediment retention and channel morphology.
Ultimately vegetation will mitigate soil erosion. The photo sequences from 2009 through 2020 below document changes in vegetation in response to the check dams.
Photo Archive
Landscape response to check dams through time
The two maps below contain an archive of photographs documenting the impact of small rock check dams since 2009. Click on any thumbnail in the left grid or a numbered marker within the map to view a temporal sequence of photographs from either the Upstream or Downstream Perspective.
Publications
Polyakov, V.O., Nichols, M.H., McClaran, M., Nearing, M.A. 2014. Effect of check dams on runoff, sediment yield and retention on small semi-arid watersheds . Journal of Soil and Water Conservation. 69:414-421. https://doi.org/10.2489/jswc.69.5.414
Nichols, M.H., Polyakov, V.O., Nearing, M.A., Hernandez, M. 2016. Semiarid watershed response to low-tech porous rock check dams . Soil Science. 181(7):275-282. doi: 10.1097/SS.0000000000000160
Nichols, M.H., Polyakov, V.O. 2019. The impacts of porous rock check dams on a semiarid alluvial fan . Science of the Total Environment. 664:576-582. https://doi.org/10.1016/j.scitotenv.2019.01.429
