These data indicate that longfin dace can be present in ephemeral stream
ecosystems within 1 day after flows begin to subside, but apparently are transient and do not persist in these ephemeral reaches.
The study was concentrated at Doctors Park, located about 10 km north of Milwaukee, because this beach had high concentrations of black sand in 1998 that was concentrated near the ephemeral stream
that flows to the lake across the beach.
The crew treated a total of 1.25 km of ephemeral stream
channel during the study period but had to treat segments repeatedly after large floods removed structures three times at the Lalio site and once at the Quandelacy site.
On the E side of the Jornada, five sites were on the W-facing mid-piedmont slope of the San Andres mountain range approximately 50 km NE of Las Cruces, New Mexico, and one site was on the W-facing piedmont slope of the Organ Mountain Range 5 km E of Las Cruces; (7) a loamy-sand alluvial fan ridge that was plowed in 1972 and in 1973 (C-RIDGE-RP), and (8) an adjacent ephemeral stream
that was plowed at the same time (C-WASH-RP); (9) a ridge (C-RIDGE) that was not plowed (approximately 0.5 km N of C-RIDGE-RP), and (10) the banks and islands of the adjacent ephemeral stream
bed (C-WASH); (11) a site heavily eroded by overland water-flow (C-EROD), on the lower piedmont slope of the San Andres range, and (12) a desert pavement site (C-PAVE) on the lower alluvial piedmont of the Organ Mountains.
In the southwestern USA, monsoon thunderstorms can produce overland flow that results in spectacular flash floods in ephemeral stream
channels (Lytle, 2000).
A dynamic behavior model of an ephemeral stream
. Journal Hydraulics Division, ASCE 101(HY5):511-528.
4) was at Ironbarks Crossing, within 50 m of Cubbo Creek, an ephemeral stream
in the Talluba Creek catchment which was dry at the time of observation.
Burrows in the Dandry, Garrawilla and Ukerbarley areas were found on forested slopes close to ephemeral streams
, while most of those in the Willala area were near rock outcrops.
As a result, previously unprotected ephemeral streams
and headwaters that are prone to destruction by mining and excavating practices could come under federal protection through permits.
The agency is now asserting that "intermittent, and ephemeral streams
, are physically, chemically, and biologically connected to downstream rivers via channels and associated alluvial deposits" and are thus under EPA control.