FLOOD01392

• County: Costilla
• Community: San Luis
• Stream Name: Rito Seco Creek, Culebra Creek
• Title: Reconnaissance Report Surface and Subsurface Flood for San Luis
• Date: 8/20/1987
• Prepared For: San Luis
• Prepared By: CWCB
• Floodplain - Doc Type: Floodplain Report/Masterplan

The largest employer of the Town and County is government and
the second largest employer is [arming, The average yearly
median family income [or the community in 1979 was $ 6,466, The
estimated family income [or the county in 1986 was $ 11. 500,
In 1984 unemployment in Costilla County and San Luis was
estimated to be over 20%,4

2,2 Description o[ Watershed Area

The San Luis Valley is bounded by a series of continuous
mountain ranges: the San Juan Mountains on the west, the
Saguache and Crestone Ranges across the northwest to northeast,
and the Sangre de Cristo Mountains on the east; Ute Mountain
and San Antonio Mountain are lonely sentinels on the south.

The waters of these mountains give birth to the Rio Grande, the
early SpaniardS named the river Rio Brave del Norte, Just
north of the present Colorado-Ne\. Mexico St.ate line. the Rio
Grande enters a deep, precipitous gor<je from which it emer<jes
into a canyon some sixty miles later:, south of Taos, The San
Luis Valley is approximately 50 mile's across east to ,,"'est and
120 miles north to south; it provides a drainage basin of 7,900
square miles and a run off of ovel' 1.', million acr,? feet of
water, more than half the run off o[ t.he whole Rio Grande Basin
above El Paso.1

The town of San Luis is located in central Costilla County in
the southeast corner o[ the San Luis Valley, The area varies in
elevation from over 12,000 ft. at the highest peaks to 7,950
[t, at the confluence of Rito Seco Creek wit.h Culebra Creek in
the Town of San Luis, The watershed drainage area is about
three miles wide and 14 miles long with an area of 42,S square
miles or 27,194 acres,

The mean annual precipitation varies [rom 10 inches at San Luis
to 22 inches at the highest elevation, About half of this
moisture occurs during the period of May through September,
Ri to Seco Creek is a perennia 1 stream; howev,er, it f luctua tes
extensively in response to summer rains, Flooding is most
common during the months of June through August.

Agriculture is the basic economic activity in the area;
however, there are only about 90 acrer,: of irrigated hay and
pasture in the Rito Seco Watershed floodplain, An additional
1,600 acres of crop land are serve,d by the, "People'> Ditch"
which passes through the Rito Seco-Culebra Creek common
floodplain and is susceptible to flood damage,l

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