WSP05425

• File Number: 8101
• Description: Arkansas River Basin Description
• State: CO
• Basin: Arkansas
• Water Division: 2
• Date: 9/1/1962
• Author: High Plains SCD
• Title: Watershed Work Plan - Limon Watershed Protection Project - Elbert and Lincoln Counties - Colorado
• Water Supply Pro - Doc Type: Report/Study

I

I

0:-'1781

- 38 -

I

Discharge damage curves were constructed fram above data
for each channel for residential, con~ercial, and municipal
properties, Discharge-frequency curves were constructed for each
channel under present conditions with the improved channel
capacities an~ with the proposed structural progrma installed.
Damage-frequency curves were developed for each channel under
present conditions and with the proposed progra~m installed for
residential, commercial, and municipal properties.

I

I

I

Average annual benefits were computed by measuring the area
under the curves.

j

I

Benefits were not evaluated for the possible savings in size
of culverts or bridges for the proposed Interstate Highway crossing
the West, Middle, and East channels. The proposed route crosses
these channels irrmediately below the site of the planned floodwater-
retarding structures,

~I
I
I

In addition to direct floodwater damages, there are indirect
damages such as loss of business, depreciation of property in the
overflow area, interruption of travel during overbank flows, and
interruption of municipal water and sewer services. For this
evaluation, indirect damages were estir"ated to be 10 percent of
direct agricultural and residential dmaages and 15 percent of
cornn,ercial and municipal damages.

I

Land Use and Treatment

The land use of the watershed was obtained by planimetering
the various land use mapped on aerial photographs.

The land use, acres, and percent of each is:

Land Use
Rangeland
Cropland
TOlm of Limon
iIiscellaneous

~
9,037
136
480
217

Percent
91,6
1.4
4.8
2,2

Total

9,870

100.0

I

The land treatment measures as shown in Table 1 were estimated
to be needed to support the structural program. Table lA shows
the measures that have been applied on the watershed area. These
land use treatments have a hydrologic effect on the watershed and
were considered in estimating rainfall runoff for present and
future project conditions.