Final FONSI and EA for hot cargo pad on Kirtland AFB - Kirtland Air ...

<strong>Final</strong> <strong>EA</strong> Addressing Construction, Operation, <strong>and</strong> Maintenance of a Hot Cargo Pad
limit floodplain development to passive uses, such as recreational <strong>and</strong> preservation activities, to reduce
the risks to human health <strong>and</strong> safety. EO 11988, Floodplain Management, directs Federal agencies to
avoid siting within floodplains unless the agency determines that there is no practicable alternative.
3.6.2 Existing Conditions
Groundwater. Kirtl<strong>and</strong> AFB is within the limits of the Rio Gr<strong>and</strong>e Underground Water Basin, which is
defined as a natural resource area <strong>and</strong> is designated as a “declared underground water basin” by New
Mexico. The Basin is regulated by the state as a sole source of potable water, although the Albuquerque
area will be supplemented in the future with surface water diverted from the San Juan <strong>and</strong> Chama rivers
to the Rio Gr<strong>and</strong>e (KAFB 2007). Two aquifers, a regional <strong>and</strong> a perched aquifer, underlie Kirtl<strong>and</strong> AFB.
The regional aquifer is present under all of Kirtl<strong>and</strong> AFB <strong>and</strong> ranges in depth from near surface to depths
of 200 feet below grade surface east of the major fault zones in the eastern portion of Kirtl<strong>and</strong> AFB, <strong>and</strong>
to depths of 350 to 500 feet below grade surface west of the fault zone. The regional aquifer is used <strong>for</strong>
the installation’s water supply. The perched aquifer is limited in area, straddling Tijeras Arroyo northeast
of the confluence of Tijeras Arroyo <strong>and</strong> Arroyo del Coyote, <strong>and</strong> occurs at depths of 200 to 400 feet below
grade surface. The perched aquifer is a result of infiltration of water from both man-made <strong>and</strong> natural
origins, with a flow direction to the southeast, <strong>and</strong> is not used <strong>for</strong> any purpose. The presence of faults has
a direct bearing on the movement <strong>and</strong> occurrence of groundwater in the vicinity of Kirtl<strong>and</strong> AFB. The
groundwater flow direction is down basin (south), with local variations <strong>and</strong> even reversals due to
groundwater pumping, specific geologic structures, or shallow influences near the Rio Gr<strong>and</strong>e (KAFB
2002).
Surface Water. Kirtl<strong>and</strong> AFB is within the Rio Gr<strong>and</strong>e watershed. The Rio Gr<strong>and</strong>e is the major surface
hydrologic feature in central New Mexico, flowing north to south through Albuquerque approximately
5 miles west of Kirtl<strong>and</strong> AFB (KAFB 2007). Water resources on Kirtl<strong>and</strong> AFB reflect its dry climate.
The average annual precipitation in Albuquerque is 9 inches, with half of the average annual precipitation
occurring from July to October during heavy thunderstorms (KAFB 2007). Surface water generally
occurs in the <strong>for</strong>m of storm water sheet flow that drains into small gullies during heavy precipitation
(KAFB 2007). Surface water generally flows across Kirtl<strong>and</strong> AFB in a western direction toward the Rio
Gr<strong>and</strong>e.
The two main surface water drainage channels on Kirtl<strong>and</strong> AFB are Tijeras Arroyo <strong>and</strong> the smaller
Arroyo del Coyote, which joins Tijeras Arroyo approximately 1 mile west of the Tijeras Arroyo Golf
Course (see Figure 3-7). Tijeras Arroyo <strong>and</strong> Arroyo del Coyote are tributaries to the Rio Gr<strong>and</strong>e, <strong>and</strong> no
jurisdictional determinations (JDs) have been made on these water features. If JDs were made, these
arroyos could be regulated under Section 404 of the CWA (see Sections 3.7.1 <strong>and</strong> 3.7.2.5 <strong>for</strong> more
in<strong>for</strong>mation on jurisdictional wetl<strong>and</strong>s). Both arroyos flow intermittently during heavy thunderstorms <strong>and</strong>
spring snowmelt, but most of the water percolates into alluvial deposits or is lost to the atmosphere via
evapotranspiration (KAFB 2002). Tijeras Arroyo, which is dry <strong>for</strong> most of the year, is the primary
surface channel that drains surface water from Kirtl<strong>and</strong> AFB to the Rio Gr<strong>and</strong>e. Precipitation reaches
Tijeras Arroyo through a series of storm drains, flood canals, <strong>and</strong> small, mostly unnamed arroyos. Nearly
95 percent of the precipitation that flows through Tijeras Arroyo evaporates be<strong>for</strong>e it reaches the Rio
Gr<strong>and</strong>e, <strong>and</strong> the remaining 5 percent is equally divided between groundwater recharge <strong>and</strong> runoff (KAFB
2002). The closest main drainage channel that sheet runoff from the proposed <strong>hot</strong> <strong>cargo</strong> <strong>pad</strong> could drain
to is the Tijeras Arroyo, which is approximately 0.75 miles south of the proposed <strong>hot</strong> <strong>cargo</strong> <strong>pad</strong>. A
clearly defined tributary to the Tijeras Arroyo is approximately 0.35 miles south of the proposed <strong>hot</strong>
<strong>cargo</strong> <strong>pad</strong>. There are no natural lakes or rivers on Kirtl<strong>and</strong> AFB. Six man-made ponds are located on
Tijeras Golf Course. At least 12 naturally occurring springs have been found on the installation (KAFB
2007).
Kirtl<strong>and</strong> AFB, NM January 2011
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