The development of the Pojoaque Basin RWS requires substantial field survey efforts to identify potential pipeline alignment and facility design constraints. Results of the surveys will be incorporated into the final design and construction of the RWS.
Surveyors will be easily recognizable by their brightly colored field vests and may be using the following equipment: waders or boots, shovels, sediment-collection sacks, digital cameras, binoculars, measuring tapes, backpacks, handheld GPS units, clipboards, and field notebooks. No surveys will be conducted on private lands without prior permission from the land owner.
Below are brief descriptions of the various resource studies that are occurring in the project area, along with their status or preliminary expected time frame.
Wildlife studies—A team of two to three biologists is conducting wildlife surveys to identify suitable habitat for a variety of species, including general wildlife, nesting raptors (eagles and hawks), and federal and state protected species. These studies will mostly be conducted from roadways with an occasional survey on foot to document the locations of suitable wildlife habitat. Wildlife surveys began in the summers of 2015 and 2016 and are continuing into early 2017 in limited areas. Additional wildlife surveys would be required before RWS construction, if pipeline or other facility locations were to change.
Vegetation studies—A team of two to three biologists conducted vegetation surveys to characterize and delineate plant communities (general and sensitive species). Preliminary vegetation surveys were conducted in May 2014. Additional surveys were conducted during the summer of 2015.
Wetlands studies—Biologists documented wetlands within 100 feet of the proposed pipeline alignment. Wetland surveys identified potential waters of the United States that may be impaired by the RWS. These studies were mostly conducted from roadways with an occasional survey on foot to document the locations of wetlands. Preliminary wetland surveys were conducted in May 2014. Additional wetland surveys were completed in fall 2015 and 2016. In early 2017, surveyors are delineating the ordinary high water mark of waterways crossed by RWS facilities.
Biological aquatic habitat studies—A team of three aquatic biologists conducted surveys to identify suitable aquatic habitat at specific sites within the general project area, including potential water diversion and infrastructure locations on the Rio Grande, at Rio Tesuque channel modification sites, and at the Rio Pojoaque Barrier Dam. Aquatic habitat was also surveyed where the proposed pipeline would cross the Rio Grande, Rio Pojoaque, Rio Tesuque, and Pojoaque Creek. These surveys were conducted in February 2014.
Cultural resource studies—Teams of two to four archaeologists are walking parallel lines (called transects) approximately 50 feet apart within the cultural resources area of analysis to identify cultural and historic resources. This level of intensive pedestrian survey is generally referred to as a Class III survey. Areas of archaeological interest are temporarily marked with pin flags, and all surface artifacts (items or pieces of items at least 50 years old intentionally made by humans) and features (non-portable evidence of human activity at least 50 years old) are documented as either a site (an area of human activity over 50 years old with evidence of intense purposeful behavior) or an isolated occurrence (an area of human activity over 50 years old with less than 25 artifacts per 1,000 square feet). In addition to archaeological resources, the Class III survey identifies and documents historic built environment resources including buildings, structures, acequias, and other objects that could be affected by the proposed undertaking. Historic buildings will be documented by a permitted architectural historian. No artifacts of any kind will be collected or retained by any employee or contractor of Reclamation. These cultural surveys have been ongoing since early 2014 and are expected to be complete in early 2017. Additional cultural surveys would be required before RWS construction if pipeline or other facility locations were to change.
Water resource studies—A team of water resources engineers evaluated a number of locations in the general project area for potential areas of erosion. Specific sites included proposed water diversion and infrastructure locations on the Rio Grande, at Rio Tesuque channel modification sites, and on the Rio Pojoaque barrier dam. The team focused on surveying major river crossings of the proposed RWS water pipeline on the Rio Grande, Rio Pojoaque, Rio Tesuque, and Pojoaque Creek. River migration and scour at these crossing locations can expose buried infrastructure over time. Areas identified during the survey as being vulnerable to erosion will be considered in the final design and construction of the RWS pipeline. These surveys were conducted in May 2014.
Inventory of existing utilities—Engineers completed an inventory of existing wells, storage tanks, pipelines, and other facilities that could be incorporated into the proposed RWS. Engineers also tested the water quality of existing wells. These surveys were completed in the summer of 2016.
Water treatment plant pilot study—Engineers constructed a pilot water treatment plant to determine necessary water treatment processes and collect operational data. The pilot plant has been collecting, treating, and analyzing water since the fall of 2014. This study was completed in the summer of 2016.
Horizontal radial well collector testing—Engineers drilled test wells and monitoring wells at the site of the proposed horizontal radial well collectors on the bank of the Rio Grande. This testing was conducted to determine whether it would be feasible to use horizontal radial well collectors to collect surface flows from the Rio Grande through the hyporheic zone (an area beneath a river or streambed that is water saturated and supports invertebrate fauna) for the RWS. The testing was completed in late 2014.
Aquifer storage and recovery (ASR) well feasibility studies—Engineers drilled exploratory wells on the Pueblo of Pojoaque to determine whether it would be feasible to use ASR wells for long-term storage of RWS water. Studies have been conducted on the use of both deep and shallow aquifers for storage. Engineers also analyzed geochemical reactions to determine whether mixing soil at the well sites with water from the Rio Grande would cause any negative impacts. These studies were completed in summer 2016.
Geotechnical investigations—Engineers are gathering soil property data throughout the project area to help with designing RWS facilities. These data are being gathered along pipeline alignments and at the proposed locations of facilities such as short-term storage tanks, pumping plants, primary source water collection facilities, and the water treatment plant. To gather data, surveyors are digging test pits and taking core samples. These studies are ongoing and are expected to continue through December 2017.
Site improvement survey—Engineers gathered topographic (i.e., elevation) data for the project area to identify conflicts with existing site improvements. Aerial surveys were conducted to take high resolution images of the project area as part of this task. Teams set out heavy paper or plastic panels, or markers, on the ground before the surveys in order to pinpoint known geographic positions such as survey monuments. The panels contrast with the color of the ground so that they can be seen in aerial photos and used to tie the photos to established coordinates. The panels were removed after the aerial surveys were completed. This survey was completed in 2014.
Rio Pojoaque barrier dam study—Engineers conducted site investigations and topographic (i.e., elevation) surveys and assessed infiltration rates in the vicinity of the Rio Pojoaque barrier dam. This information is helping Reclamation and the Pueblo de San Ildefonso design a project to improve irrigation on the Pueblo de San Ildefonso.