Most of western North America has been severely grazed by cattle, causing grasslands to deteriorate and desert scrub expansion. Climate in arid and semi-arid regions is often typified by short, intense rainfall events which contribute to short-term flooding and erosion. Associated arroyo cutting occurs when ephemeral creek beds are carved into the floodplain when erratic overland flow occurs; this lowers water tables, depleting surface and subsurface water supplies. When surface runoff is high, little recharge infiltrates to the basin aquifer, and high-intensity flow transports heavy sediment loads to channels, contributing to nonpoint source pollution in surface water bodies.

People living in arid land environments all over the globe have developed ways to manipulate the earth’s surface to benefit and sustain agricultural practices via water harvesting. Archaeologists have discovered such features dating back to Before the Common Era and in the Madrean Archipelago Ecoregion (Sky Islands) built over a thousand years ago.
Federal agencies, including the US Forest Service, US Fish and Wildlife Service, US Parks Service, and Bureau of Land Management, are major land managers in this region, concerned with developing sustainable water supplies and vegetation for future generations and engage in best management practices. Additionally, private ranch owners have identified an immediate need for the adoption of proper conservation strategies in this area to control the eutrophication in downstream water supplies and to prevent further watershed degradation.
One solution is to install rock detention structures, such as (i.) a one rock dam (one-rock high) bed of rocks (en espanol: trinchera) can be in channels or hillslopes, (ii.) a check dam (gully plug), usually ~3 foot high loose rock structure set into channel, and/or (iii.) a rock gabion, which consists of rocks rapped in wire cage and keyed into channel (see Drawings)

An effort to develop soil and water conservation measures in local riparian zones has recently been revived in both private and public lands in this region using rock detention structures to restore landscapes and create resiliency to change. Specific ally, structures are built to detain rainwater-runoff to (i.) increase infiltration and improve recharge, (ii.) increase surface water for plants and animals, and (iii.) reduce erosion, stabilize soil and prevent downstream transport. These goals have been identified colloquially, but not qualified nor quantified scientifically. We have broken these expected results into a list of Ecosystem Services.
Broad Science Questions
As such, we have developed a series of scientific questions to address their impacts both qualitatively and quantitatively, and the list keeps growing.
Project Objectives
I. Determine metrics to discern effectiveness of rock detention structures (quantifiable results).
II. Work with partners to determine where new structures should be…..
1. For flood prevention?
2. For vegetation and habitat?
3. To “heal” the land?
4. For groundwater recharge?
5. To reduce erosion and nonpoint source pollution (sedimentation in streams)?
6. To increase surface water?
7. To armor landscapes?
Scientific methodology
Our research is based on the hydrologic cycle that describes water as either: a) evaporated or transpired to the atmosphere; b) stored in the soil or in underground aquifers; or c) discharged to a nearby waterway (Fig. 3).
- Terrestrial monitoring documents the hydrological impacts of water harvesting devices and helps identify sites for future installation in Patagonia.
- Landsat Thematic Mapper satellite imagery and the derived Normalized Difference Vegetation Index (NDVI) values are being used to monitor changes in vegetation greenness at a desert wetland in San Bernardino.
- Hydrological geospatial models, including the Soil and Water Assessment Tool (SWAT) and the Kinematic Runoff and Erosion Model (KINEROS2) are being used (with Terrestrial LiDAR (T-LiDAR) datasets) to monitor changes in surface flow, infiltration, and sediment build-up at new check dams and detention features in Nogales, Patagonia, and at the Babocomari.
- T-LiDAR data and 2-D hydraulic models are also being used to examine changes in vegetation structure and channel dimensions in Patagonia.
- Hydrographs are developed using Continuous Slope Area methods to be input to calibrate watershed models for long-term predictions in the Chiricahua Mountains.

Acknowledgements
The U.S. Geological Survey (USGS) is a Federal agency that conducts science about the Earth, its natural and living resources, natural hazards, and the environment. This research is part of the Core Science Systems (CSS) Change Mission Area of the USGS, which undertakes scientific research using monitoring, remote sensing to address the effects of climate and land use change. The CSS provides the scientific foundation upon which policymakers, natural resource managers, and the public make informed decisions about the management of natural resources. Funding comes from the Land Change Science Program (LCSP) to understand the patterns, processes, and consequences of changes using models to predict scenarios of future conditions, and conduct integrative, holistic assessments.
Below are science projects managed under the Aridland Water Harvesting Study.
Cienega Ranch - Semi-desert Native Grassland Restoration
Research in the Los Planes Watershed – Water Cycle Augmentation
Ciénega San Bernardino - Wetland Restoration
Patagonia - Gully Restoration
Nogales, Sonora - Flood Control
Chiricahua Mountains - Reduction of Channel Gradients
Babocomari - Managed Aquifer Recharge
Below are data releases published by the Aridland Water Harvesting Study.
Database of Cienega Locations in Southwestern United States and Northern Mexico
Watershed Pairing of Sub-Basins within Smith Canyon Watershed using a Hierarchical Clustering Approach
Short Term Vegetation Response Study at Watershed Restoration Structures in Southeastern Arizona, 2015 - 2019
Data Release for Analysis of Vegetation Recovery Surrounding a Restored Wetland using the Normalized Difference Infrared Index (NDII) and Normalized Difference Vegetation Index (NDVI)
Below are journal articles and reports published by the Aridland Water Harvesting Study.
Natural infrastructure in dryland streams (NIDS) can establish regenerative wetland sinks that reverse desertification and strengthen climate resilience
Five year analyses of vegetation response to restoration using rock detention structures in southeastern Arizona, United States
Commentary: Dryland watershed restoration with rock detention structures: A nature-based solution to mitigate drought, erosion, flooding, and atmospheric carbon
Wildfire probability models calibrated using past human and lightning ignition patterns can inform mitigation of post-fire hydrologic hazards
Flood resilience in paired US–Mexico border cities: A study of binational risk perceptions
Integrating urban planning and water management through green infrastructure in the United States-Mexico border
A shared vision for enhancing ecological resilience in the U.S. - Mexico borderlands: The Sky Island Restoration Collaborative
Hierarchical clustering for paired watershed experiments: Case study in southeastern Arizona, U.S.A.
Developing climate resilience in aridlands using rock detention structures as green infrastructure
Editorial: Combining the science and practice of restoration ecology-Case studies of a grassroots binational restoration collaborative in the Madrean Archipelago Ecoregion (2014- 2019)
Remote sensing analysis to quantify change in woodland canopy cover on the San Carlos Apache Reservation, Arizona (1935 vs. 2017)
Preliminary assessment of carbon and nitrogen sequestration potential of wildfire-derived sediments stored by erosion control structures in forest ecosystems, southwest USA
Ecosystem services of riparian restoration: A review of rock detention structures in the Madrean Archipelago Ecoregion
Below are news stories and announcements about the Aridland Water Harvesting Study.
Researchers, partners and stakeholders
Sky Island Restoration Collaboration (SIRC)
A new consortium is working to share and integrate conservation efforts in the Madrean Sky Island Archipelago. The collective goal is to conduct a landscape-level resource assessment, at a multiple watershed scale, to evaluate condition and prioritize areas and methods for restorative treatment.
Most of western North America has been severely grazed by cattle, causing grasslands to deteriorate and desert scrub expansion. Climate in arid and semi-arid regions is often typified by short, intense rainfall events which contribute to short-term flooding and erosion. Associated arroyo cutting occurs when ephemeral creek beds are carved into the floodplain when erratic overland flow occurs; this lowers water tables, depleting surface and subsurface water supplies. When surface runoff is high, little recharge infiltrates to the basin aquifer, and high-intensity flow transports heavy sediment loads to channels, contributing to nonpoint source pollution in surface water bodies.

People living in arid land environments all over the globe have developed ways to manipulate the earth’s surface to benefit and sustain agricultural practices via water harvesting. Archaeologists have discovered such features dating back to Before the Common Era and in the Madrean Archipelago Ecoregion (Sky Islands) built over a thousand years ago.
Federal agencies, including the US Forest Service, US Fish and Wildlife Service, US Parks Service, and Bureau of Land Management, are major land managers in this region, concerned with developing sustainable water supplies and vegetation for future generations and engage in best management practices. Additionally, private ranch owners have identified an immediate need for the adoption of proper conservation strategies in this area to control the eutrophication in downstream water supplies and to prevent further watershed degradation.
One solution is to install rock detention structures, such as (i.) a one rock dam (one-rock high) bed of rocks (en espanol: trinchera) can be in channels or hillslopes, (ii.) a check dam (gully plug), usually ~3 foot high loose rock structure set into channel, and/or (iii.) a rock gabion, which consists of rocks rapped in wire cage and keyed into channel (see Drawings)

An effort to develop soil and water conservation measures in local riparian zones has recently been revived in both private and public lands in this region using rock detention structures to restore landscapes and create resiliency to change. Specific ally, structures are built to detain rainwater-runoff to (i.) increase infiltration and improve recharge, (ii.) increase surface water for plants and animals, and (iii.) reduce erosion, stabilize soil and prevent downstream transport. These goals have been identified colloquially, but not qualified nor quantified scientifically. We have broken these expected results into a list of Ecosystem Services.
Broad Science Questions
As such, we have developed a series of scientific questions to address their impacts both qualitatively and quantitatively, and the list keeps growing.
Project Objectives
I. Determine metrics to discern effectiveness of rock detention structures (quantifiable results).
II. Work with partners to determine where new structures should be…..
1. For flood prevention?
2. For vegetation and habitat?
3. To “heal” the land?
4. For groundwater recharge?
5. To reduce erosion and nonpoint source pollution (sedimentation in streams)?
6. To increase surface water?
7. To armor landscapes?
Scientific methodology
Our research is based on the hydrologic cycle that describes water as either: a) evaporated or transpired to the atmosphere; b) stored in the soil or in underground aquifers; or c) discharged to a nearby waterway (Fig. 3).
- Terrestrial monitoring documents the hydrological impacts of water harvesting devices and helps identify sites for future installation in Patagonia.
- Landsat Thematic Mapper satellite imagery and the derived Normalized Difference Vegetation Index (NDVI) values are being used to monitor changes in vegetation greenness at a desert wetland in San Bernardino.
- Hydrological geospatial models, including the Soil and Water Assessment Tool (SWAT) and the Kinematic Runoff and Erosion Model (KINEROS2) are being used (with Terrestrial LiDAR (T-LiDAR) datasets) to monitor changes in surface flow, infiltration, and sediment build-up at new check dams and detention features in Nogales, Patagonia, and at the Babocomari.
- T-LiDAR data and 2-D hydraulic models are also being used to examine changes in vegetation structure and channel dimensions in Patagonia.
- Hydrographs are developed using Continuous Slope Area methods to be input to calibrate watershed models for long-term predictions in the Chiricahua Mountains.

Acknowledgements
The U.S. Geological Survey (USGS) is a Federal agency that conducts science about the Earth, its natural and living resources, natural hazards, and the environment. This research is part of the Core Science Systems (CSS) Change Mission Area of the USGS, which undertakes scientific research using monitoring, remote sensing to address the effects of climate and land use change. The CSS provides the scientific foundation upon which policymakers, natural resource managers, and the public make informed decisions about the management of natural resources. Funding comes from the Land Change Science Program (LCSP) to understand the patterns, processes, and consequences of changes using models to predict scenarios of future conditions, and conduct integrative, holistic assessments.
Below are science projects managed under the Aridland Water Harvesting Study.
Cienega Ranch - Semi-desert Native Grassland Restoration
Research in the Los Planes Watershed – Water Cycle Augmentation
Ciénega San Bernardino - Wetland Restoration
Patagonia - Gully Restoration
Nogales, Sonora - Flood Control
Chiricahua Mountains - Reduction of Channel Gradients
Babocomari - Managed Aquifer Recharge
Below are data releases published by the Aridland Water Harvesting Study.
Database of Cienega Locations in Southwestern United States and Northern Mexico
Watershed Pairing of Sub-Basins within Smith Canyon Watershed using a Hierarchical Clustering Approach
Short Term Vegetation Response Study at Watershed Restoration Structures in Southeastern Arizona, 2015 - 2019
Data Release for Analysis of Vegetation Recovery Surrounding a Restored Wetland using the Normalized Difference Infrared Index (NDII) and Normalized Difference Vegetation Index (NDVI)
Below are journal articles and reports published by the Aridland Water Harvesting Study.
Natural infrastructure in dryland streams (NIDS) can establish regenerative wetland sinks that reverse desertification and strengthen climate resilience
Five year analyses of vegetation response to restoration using rock detention structures in southeastern Arizona, United States
Commentary: Dryland watershed restoration with rock detention structures: A nature-based solution to mitigate drought, erosion, flooding, and atmospheric carbon
Wildfire probability models calibrated using past human and lightning ignition patterns can inform mitigation of post-fire hydrologic hazards
Flood resilience in paired US–Mexico border cities: A study of binational risk perceptions
Integrating urban planning and water management through green infrastructure in the United States-Mexico border
A shared vision for enhancing ecological resilience in the U.S. - Mexico borderlands: The Sky Island Restoration Collaborative
Hierarchical clustering for paired watershed experiments: Case study in southeastern Arizona, U.S.A.
Developing climate resilience in aridlands using rock detention structures as green infrastructure
Editorial: Combining the science and practice of restoration ecology-Case studies of a grassroots binational restoration collaborative in the Madrean Archipelago Ecoregion (2014- 2019)
Remote sensing analysis to quantify change in woodland canopy cover on the San Carlos Apache Reservation, Arizona (1935 vs. 2017)
Preliminary assessment of carbon and nitrogen sequestration potential of wildfire-derived sediments stored by erosion control structures in forest ecosystems, southwest USA
Ecosystem services of riparian restoration: A review of rock detention structures in the Madrean Archipelago Ecoregion
Below are news stories and announcements about the Aridland Water Harvesting Study.
Researchers, partners and stakeholders
Sky Island Restoration Collaboration (SIRC)
A new consortium is working to share and integrate conservation efforts in the Madrean Sky Island Archipelago. The collective goal is to conduct a landscape-level resource assessment, at a multiple watershed scale, to evaluate condition and prioritize areas and methods for restorative treatment.