Client M.A Mortenson
Location Luna County, New Mexico
Scope 50.4 Megawatts, 28 turbines over 1,900 acres
Contractor Element Power

Macho Springs Wind

Project Details

Westwood’s Role

  • Civil Engineering
  • Surveying
  • Aerial Mapping

Overview

Westwood was initially hired to provide straightforward civil engineering and surveying services for the Macho Springs Wind Project after preliminary design work had been completed. During routine pre-construction analysis, however, Westwood identified potentially significant hydrology issues affecting site. The client hired Westwood to provide a detailed analysis and solution for flooding concerns.

Inaccurate FEMA Maps Cause Glitch in Design

Preliminary designs created before Westwood’s involvement relied on FEMA flood plain maps. Prior experience with FEMA maps caused Westwood to take a closer look to ensure accuracy as part of the routine engineering work. Eight turbines were identified as being susceptible to flooding. Westwood recommended the client perform a detailed hydrology analysis to accurately determine water flow depth and velocities and the associated threat to the project. The detailed study bore out Westwood’s initial assumptions; eight turbines, as well as other important equipment, were in the flood zone.

Although the water flow was found to be over a much larger area and deeper than originally assumed, Westwood determined the vulnerable turbines could stay in place, provided soil improvements were added to handle the erosive flows. Below ground riprap was installed around the turbines to prevent erosion in the event of flooding. Boulders and rock were buried beneath the surface to prevent any damaging soil washout that could compromise the integrity of the turbine foundations. By installing the protection measures below ground, roads, maintenance, and access were not affected.

Hydrology Study Reveals Surprise

More surprising was that the study revealed the project’s entire substation to be inside the flood zone. The solution was a simple, but effective one; Westwood designed a berm to channel water away from the electrical equipment. Had the project been built based on the original plan, without incorporating Westwood’s hydrology study recommendations, a large and costly part of the project would have been compromised. Relative to the cost of potential damage, the hydrology analysis and study saved the client significant money in the long term.