The Cienaga Restoration

Tom & Cinda Cole purchased a ranch in New Mexico that has a lengthy reach of the Burro Ciénaga that runs through it. Ciénaga is a word from the Spanish colonial period that literally means “cien-aguas” or “100-waters.”  A ciénaga is not a river, stream or creek, but rather a groundwater dependent ecosystem of slow moving water or marsh, associated with perennial springs and shallow headwater streams. Ciénagas are vegetated freshwater wetlands with permanently saturated soils, maintained naturally by geologic features.

Historically, many of these shallow surface waterways extended from one canyon wall to the other, often as wide as a football field is long.  They were common in the Southwest before the 1880s but now only remnants of historic ciénagas remain. Virtually every ciénaga in the Southwest has been degraded due to near-total harvesting of beaver in the 1820s, drought, overstocking of cattle, agricultural practices, and the absence of fire.  Many riparian habitats containing willows, cottonwoods and other riparian plants found in today’s Southwest were ciénagas 150 years ago.  Now they are incised and eroded into creeks, often ephemeral or gone completely.

Springs ecosystems are among the most structurally complicated, ecologically and biologically diverse, productive, evolutionary provocative, and threatened ecosystems on earth and function as ‘keystone ecosystems.’  They exert vastly disproportionate impacts on regional ecology, evolutionary processes, and sociocultural economics in relation to their size.

Early Spanish and later Anglo settlers gathered along ciénagas.  Land surface incision or down-cutting linked to wagon roads and livestock trailing – sometimes coupled with farm related dams, dikes and ditches – caused channeling which concentrated and increased the erosive power of water flow.  As the channels down-cut and these incisions migrated upstream, gentler surface flows were replaced by fast-water gullies.  This damage was worsened by several decades of drought.  Water tables dropped and ciénagas were dewatered.

Once gullied, ciénagas are unlikely to self restore using natural processes because rapid gully flow prevents deposition of sediment and absorption of water.  Installing grade control structures and flood-water deflectors can transform a damaged ciénaga from erosional to depositional, halt further down-cutting and raise its bed: slowing the water, retaining more water longer in the ciénaga and adjacent lands, all toward enlarging the wetland and recapturing the ciénaga’s historic function. The ciénaga restoration will take around two decades.

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