&EPA
         USDA
          NRCS
  -—-
'f i
EPA
908
  00:2
                       United States -
                       Environmental Protection
                       Agency
                  Region 8
                  8EPR-EP
             EPA 908-F-98-002
             August 1999
United States
Department of
Agriculture
Natural Resources
Conservation
Service
       The  South Platte  River  in Colorado
       s. '

-------
                                                    Introduction
           The South Platte  River
           begins its journey in the
          mountains of central Colo-
   rado and flows northeast for 450
   miles across the Great Plains to its
   confluence with the North Platte
   River at North Platte, Nebraska. The
"^ South Platte watershed covers more
 *" than 23,000 square miles and is
r' located in parts of three states: Colo-
N  rado (79 percent of  the basin),
*  Nebraska (15 percent of the basin),
  and Wyoming (6 percent of the
  basin). At its source near the Con-
  tinental Divide, the river  flows
  through national forests, then out
  onto the plains through prairie and
  farmland of Colorado's northeastern
  counties. The South and North Platte
  Rivers join to form the Platte River,
  which flows to the Missouri River.
      The river is as essential today
  as it was to the early human inhab-
  itants who gathered along the foot-
hills and plains river corridor to hunt
and gather food. A variety of species,
including  prehistoric  horses,
mammoths  and
bison,  thrived
along the river.
Many areas along
the river are rich
with prehistorical
and  historical
clues as to who
occupied the land.
The river is as essential today
as it was to early human
inhabitants who gathered
along the foothills and plains
river corridor to hunt and
gather food.
The Apache utilized the river area
until 1700. Utes occupied the area
from 1700  to 1750. Then  the
Comanche were in the area from
1750 to 1820. There is also evidence
that the Arapaho and Cheyenne
moved along the river during the
19th century until settlers from the
eastern United States discovered the
pristine area in the mid-1800s.
     The river valley was very
tempting to settlers, and an early
agricultural community was estab-
lished near Greeley. The settlers from
the east built a canal system that is
still the foundation for the third most
productive agricultural community
in the United States. Many prop-
erties along the South Platte have
been placed on  the National
Register  of  Historic   Places.
Structures  like churches,  banks,
courthouses, railroad  depots,
ranches, farms and schools  remain
              in the river valley.
              Other  properties
              include breweries,
              saloons, forts, fur
              trading posts, and
              the Rainbow Arch
              Bridge which was
              built in 1923 near
              Fort Morgan.
   2
onto
 d farmland of Co/0
      national f°re
                                                   'trough P*

-------
                                                           History
        The SouthPlatte watershed
        is rich in human history; has
        an abundance of spectacu-
lar scenery; and played a major role
in the development of mining,
agriculture and communities along
Colorado's Front Range. From early
people living in the area at the end
of the last Ice Age, to the growth of
modern cities and towns, and one of
the richest agricultural regions in
the United States, the watershed
continues to be a scene of change.
Some tributaries have been sites of
past mining activities in places like
Central City, Gold Hill, Caribou and
^Manhattan.
     Major Stephen Long led an
expedition in 1819-1820 to explore
the Louisiana Purchase Territory,
including the source of the South
Platte.  For whatever reason, he
decided not to follow the river to its
source. Instead, Long sent several of
his party to climb Pikes Peak for the
first time. The naturalists did find
many new plants and animals, but
their impression was that the plains
along the South Platte were as
barren as the deserts.
     Fur forts appeared along the
river at sites such as Fort Vasquez,
Fort St. Vrain and Fort Lupton. Fur
trappers from Canada and mountain
men moving west from St. Louis
made their way up the Cache la
Poudre and other rivers searching
for beaver. Other forts sprang up
along the river in the northeastern
corner of Colorado at Fort Morgan
and Julesburg. But competition from
Bent's Fort on the Arkansas River
drove some out of business, and by
the mid-1800s, most of the forts were
abandoned.  In  1858, gold was
discovered at the confluence of
Cherry Creek and the South Platte,
not far from present-day downtown
Denver. A year later, gold was dis-
covered at the confluence of Ralston
and Clear Creeks, starting the Pikes
Peak Gold Rush and the beginning
of the settlement of Colorado.
     Much has changed along the
South Platte  in the last 140 years
since the Long expedition. The river
and some of its tributaries have been
mined, dammed and channeled.
Cities and towns have flourished
along its banks and are home to
several million people. Rivers and
streams flowing through mountain
and plains communities are the
sources of water for domestic use,
agriculture  and recreation.  Most
recently, the South Platte through the
Denver metropolitan area is being
restored for natural recreational and
aesthetic values. Though changed,
the South Platte still reminds us
of the past and offers challenges
for the future.
                      South Platte River, 1880
  U.S EPA Headauarters Library
         Mai! coa& 3404T
  1200 Pennsylvania Avenue NVV
      Washington, DC 20460
          202-566-0556

-------
        Along the South Platte and
         its tributaries is some of
         the  most  impressive
mountain and valley scenery to be
found in Colorado. The South and
Middle Fork headwaters of the
South Platte are in the Mosquito
Range. These forks flow down into
South Park, a high-altitude grass-
land,  then into Antero, Spinney
Mountain    and    Elevenmile
reservoirs. The river
eventually flows into
Platte  Canyon, and
from   there   into
Chatfield Reservoir.
From Chatfield,  the
South  Platte  flows
through several com-
munities, including
Denver, then out onto
the plains through
small  towns  and
farms. Tributaries join
the South Platte in the
mountains and on the
plains. Many of these
tributaries begin in
national forests, wilderness  areas
and a national park. The St.  Vrain
River has its headwaters in the
Indian Peaks Wilderness Area and
      Tributaries

    in Rocky Mountain National Park.
    It joins the South Platte near the site
    of old Fort St. Vrain south of Greeley.
    These tributaries often have colorful
    names and histories, such as Cache
    la Poudre, named by Canadian fur
    trappers after they stored gunpow-
    der along its banks in the early 1800s.
    On the eastern plains are small
    intermittent streams with names like
    Crow, Kiowa and Pawnee Creeks.
                                                                                                                           Cheesman Dam
Cache la Poudre River, tributary of the South Platte
        The watershed has endured
    disastrous floods.  In May 1864,
    heavy rain caused 19 deaths along
    Cherry Creek and the South Platte
in Denver. Heavy rains in August
1933 caused the Castlewood Dam on
Cherry Creek to break, resulting in
loss of life and property in Denver.
The Denver area was flooded again
in June 1965 from heavy rains.
Floodwater reached as far as  the
lower downtown area, causing hun-
dreds of millions of dollars damage.
On  the evening of July 31, 1976,
a cloudburst  dumped nearly a foot
             of rain in  the Big
             Thompson River
             Canyon. More than
             150 lives were lost
             amid   extensive
             damage. High in the
             Mummy Range in
             Rocky  Mountain
             National Park, Lawn
             Lake Dam failed on
             July 15, 1982. Fall
             River, a tributary of
             the Big Thompson,
             carried a wall of
             water through  the
             town of Estes Park,
             causing damage of
$30 million. On July 28,1997, Colo-
rado State University, in the path of
a flood from a 10-inch cloudburst on
a small tributary, sustained more
than $100 million in damages.

-------
Water  Diversion
Canal in Northern Colorado Water Conservancy District
           Water  users  in  the
           South Platte watershed
           .nclude cities, indus-
tries, farmers and ranchers, and
individual households. Water is also
important  to recreationists like
           boaters and anglers.
           And obviously, plants
           and animals  in their
           natural habitats need
           water. In order to meet
           the  water  require-
           ments  of   natural
           ecosystems and the
           growing population,
the amount of water available from
the South  Platte  basin must be
supplemented.
     Water conservancy districts are
the primary providers of water from
the South Platte basin. They deliver
water from the basin as well as wa-
ter diverted from other watersheds.
The Northern Colorado Water Con-
servancy District is a major water
supplier in the basin. The district
serves water users  150 miles east to
west, and 65 miles north to south in
northeastern Colorado. Lands along
the South Platte and several of its
major tributaries, including the
Cache la Poudre and Big Thompson
Rivers, are in the district. Water,
including supplemental water, is
delivered to 29 cities and towns, 120
ditch companies, 60 reservoir com-
panies, and 620,000 acres of irrigated
farmland—1.5 million acres alto-
gether in Colorado's northern Front
Range and northeastern plains.
     A public agency created in
1937, the Northern Colorado Water
Conservancy District's primary
function  is  operation  of  the
Colorado-Big Thompson Project.
Built during 1938 to 1957, this is the
largest transmountain diversion
project in Colorado, transferring
water from the upper Colorado
River basin to the South Platte River
basin. The project's West Slope
Collection System in the upper Colo-
rado River basin includes Lake
Granby, Willow Creek Reservoir,
Shadow Mountain Reservoir, Green
Mountain Reservoir and Grand
Lake. It can collect and deliver up to
310,000 acre-feet (an acre-foot is one
foot of water covering one acre) of
water annually. Water is transported
under Rocky  Mountain National
Park through the 13-mile-long
Alva  B.  Adams  Tunnel,  and
delivered by the project's East Slope
Storage and Distribution System.
                                                                                                                 5

-------
                                                       Mining
      Seekers of fortune rushed
       to the South Platte basin
       in 1859. Gold that could
be washed  out of sand  and
gravel in streams was found
near the present site of Idaho
Springs in January 1859. The
discovery of gold in rock
veins came just east of
present-day Central City in
May 1859. With its abundant
water supply for sluices and
water wheels, Black Hawk
quickly became the milling
center for gold ore mined. At
first, primitive crushers were
used, but these  soon gave
way  to stamp mills where
hammers pounded the ore
into fine particles. Lastly, the
gold  was chemically sepa-
rated with mercury. By 1864,
the rich surface ores began to
play out, and the deeper
mines were yielding more
complex sulfide ores. The
simple stamp mills could
recover only a fraction of the gold
from these ores.
     Smelting at high tempera-
tures provided  a  solution.
Successful smelting began in 1868
and the industry was revitalized. In
1872, the Colorado Central narrow-
gauge railroad line ran through
                                 mining towns. A tramway railway
                                 even smaller than the narrow-gauge
                                 was extended  to Central City in
                                 1878, making it easier and cheaper
          Miners, late 1800s—Courtesy Colorado Historical Society

                                 for the mines in the surrounding
                                 hills to get their ore to the mills.
                                      The economic boom was an
                                 environmental disaster. Streams
Clear Creek Canyon connecting
Black Hawk with Denver. Coal was
shipped to the smelters and mills
along Clear Creek, and supplies
and mining waste. Trees were cut
down for miles around for timber-
ing mine shafts and fueling engines,
mills and smelters. This made
      the narrow gulch subject to
      periodic flooding, eventually
      raising the level of Central
      City's Gregory Street by a full
      story in some places. Toxic
      fumes produced by coal dust
      and sulfur refining were
      dangerous and unsightly. The
      crashing   stamp   mills
      and screaming steam loco-
      motives made for intolerable
      noise levels.
          The  4 Vi-mile  Argo
      Tunnel was built to intersect
      the largest underground
      veins in the district, but the
      tunnel  facilitated draining
      more than mining. Acid mine
      drainage from the tunnel,
      along with drainage from
      many other mines in the area,
      polluted Clear Creek, now
      a drinking water source
for more than 250,000  people.
The pollution of  the Clear Creek
basin resulted in specific sites in
the area undergoing a Superfund
cleanup.
                               were  shipped  to the growing   were polluted by human, animal

-------
                                                    Agriculture
Agriculture accounts for about 37 percent of the land use in the South Platte River basin. Essentially all of this acreage is located in the plains east of the
Rocky Mountains.
         Agriculture  is  vital  to
         Colorado and the nation.
         It is of major importance
in the South Platte basin. Agriculture
accounts for about 37 percent of the
land use in the South Platte River
basin. Essentially all of this acreage
is located in the plains east of the
Rocky Mountains. The total amount
of land in crops in the basin is about
4.1 million acres. Of this, about 1.4
million acres are irrigated, 1.6 mil-
lion acres are non-irrigated, and the
remainder is partially irrigated.
     Corn, hay, dry beans, and
barley represent the major irrigated
crops in the basin. Winter wheat
is  the major non-irrigated crop
grown in the basin, and in terms
of acres harvested, represents the
most important crop grown in the
basin.
     In addition  to  field-crop
production, cattle and hog feeding
operations represent large agricul-
tural interests. There are approxi-
mately 298 cattle feeding operations
in the basin and around 95 hog
operations.  Other livestock opera-
tions found in the South Platte River
basin  include lambs, chickens,
turkeys, and exotics such as bison.
                                                         ">
                              South P'a1
                  '"'fare
                                          U.S  EPA Hesdouarters Library
                                                Maii cooe 34(HT
                                          1200 Periuavv3'j(£ Avenue NVV
                                            Washmurori DC  20460
                                                 202-565-0556

-------
Fish and wildlife
resources in the South
Finite watershed are
among the most out-
standing in the nation.
        The allure  of  Colorado
        encompasses many aspects
        of the  state's  natural
resources and recreational oppor-
tunities. Fish and
wildlife resources
in   the  South
Platte watershed
are  among  the
most outstanding
in  the  nation.
Great differences
in elevation cause
wide varieties of
wildlife habitats,
which   provide
diverse plant and
animal species.
     In the moun-
tain areas of the
watershed, mule
deer, elk, black
bear,   mountain
lions,    bighorn
sheep,  mountain
goats,  snowshoe
hares,    bobcats,
ground and  tree
squirrels,   mar-
mots, beaver, and other smaller
mammal species  are prevalent.
     The foothills and plains—and
especially the plains riparian areas—
are home to rabbits, coyotes, prong-
horn, white-tailed deer, foxes,
         prairie dogs, raccoons
         and muskrats, plus other
         small mammals.
             Birds that occupy
         the  South Platte water-
         shed, either year-round
         or  seasonally,  include
         bald and golden eagles;
                                                                                                                      Wih
               ospreys; numerous species of hawks,
               falcons and owls; a variety of ducks,
               geese, grouse, prairie chickens,
               herons, cranes, pelicans,  rails,
               plovers and doves;  and many
               species of songbirds.
                                      The importance of wetlands,
                                 both in the mountains and on the
                                 prairies, is reflected in the  wide
                                 range of plants and animals that
                                 flourish in these essential habitats.
                                      Aquatic wildlife is diverse and
                                 important in the watershed. The
                                 native greenback cutthroat  trout
                                 is recovering from the brink of
                                 extinction and is now the Colorado
                                                                                                             Prairie Chicken

-------
life
    Greenback Cutthroat Trout
                                 state fish.  Other  trout
                                 include rainbow, brown
                                 and  brook.  Mountain
                                 whitefish  are found  in
                                 many streams. Bass, blue-
                                 gill, catfish, crappie, carp,
                                 muskie and pike have been
                                 introduced to warm-water
                                 ponds and reservoirs in the
                                 watershed.
                                      Wildlife in the South
                                 Platte basin is important
                                 simply by existing.  It
                                 also offers recreational
opportunities, from watching and
photographing, to fishing and hunt-
ing.  The Colorado Division  of
Wildlife has designated numerous
viewing areas across the basin,
and also owns and manages many
state wildlife areas for recreation.
Public lands managed by the USDA
Forest Service, Bureau of Land
Management and National Park
Service are available to all.
                                                                                                                          Elephantella
                                                                                Wild Basin willows in Rocky Mountain National Park

-------
Enhancing recreational areas, open space and wildlife areas along the river are major priorities for local urban governments.
       The South Platte River is
       vital to the quality of life in
       the Denver metropolitan
area. For many years the river was a
place to dispose of waste. Now the
South Platte is an important amenity.
From Chatfield Dam to Denver's
southern boundary, the river is
bordered largely by open space, and
then by suburban Littleton, Sheridan
and Englewood. In the 10-mile
Denver stretch, 300,000 people live
within a mile of the river's banks.
 As the river moves into Adams
 County, there is a concentration of
 commerce and industry, then farm-
 land. Most of this 20-mile corridor
 is publicly owned.
     Enhancing and maintaining
 recreational areas, open space and
 wildlife areas along the  river are
 major priorities for local urban
 governments. The South Platte
•greenway now extends 25 con-
 tinuous miles from Chatfield Dam
 well into Adams County. Many
 tributary trail connections,  including
            the 70.^.
trails along Cherry Creek, Bear
Creek, Highline Canal and Sand
Creek make this one of the best
greenway systems in the U.S. The
Denver Water Department manages
a streamflow program in the sum-
mer months to improve rafting,
kayaking and  fishing. Metro area
jurisdictions are improving water
quality to enhance fishing and
recreation. Open space and wildlife
habitats along  the river have been
expanded,  with  many areas
revegetated with native species.
                                                                        300
                                                                            000

                                                                                                                Denver   Urb
                                                                                             *"
                                                                                               tft/n
                                                           banks. As the
                                                                                                           Of the

-------
                                                                                                                               Confluence Park
an   Corridor
                               The South Platte greenway now
                               extends 25 continuous miles from
                               Chatfield Dam well into Adams
                               County. Many tributary trail con-
                               nections make this one of the best
                               greenway systems in the country.
                                                     This cleaner, more scenic
                                                     and enjoyable river front
                                                     is a primary catalyst for
                                             economic  growth. In Denver's
                                             central Platte valley, the 1.56-mile
                                             riverfront is a focal point for new
                                             housing and commercial develop-
                                             ment. The 29-acre Commons Park,
                                             built on reclaimed industrial land
                                             along the river, is the centerpiece of
                                             the 6-million-square-foot Commons
                                             Neighborhood. This area boasts a
                                             world-class fresh- and  salt-water
                     -  County,  ffy
                   (0S             «>«
                                    aquarium. Upstream of Denver,
                                    economic development has resulted
                                    in restaurants, an amusement park,
                                    two golf courses, a regional display
                                    garden, residences  and  office
                                    buildings, and relocated commercial
                                    enterprises adjacent to the river.
                                        Partnering is an  essential
                                    component to open space acquisi-
                                    tion and economic growth. The
                                    Greenway Foundation led initial
                                    efforts to enhance the river corridor.
                  Under Denver's South Platte River
                  Commission, public entities have
                  developed strong networks of local,
                  state and federal agencies and non-
                  profit and private interest groups.
                  Local governments, including South
                  Suburban Parks and Recreation
                  District, City and County of Denver,
                  and Adams County, provide leader-
                  ship in managing  the natural
                  character of the 20-mile-long urban
                  river corridor.
   "loves /nt°
c°ncenfratio" °f
U.S  EPA Headquarters Library
19nnDMa"code3404T
^00 Pennsylvania Avenue NVV
   Wash/ngton, DC  20460
    <\6' 202-566-0556
                                                                                 fy.

-------
Acknowledgments
We wish to acknowledge contributions from the following:
City and County of Denver
Colorado Historical Society
U.S. Environmental Protection Agency
USDA Natural Resources Conservation Service
Northern Colorado Water Conservancy District
Petra Barnes, USDA Natural Resources Conservation Service
Rob Henneke, U.S. Environmental Protection Agency
Paul D. Mclver, U.S. Environmental Protection Agency
Lee Shanklin, U.S. Environmental Protection Agency
Wyn-Nelle 'White, USDA Natural Resources Conservation Service
&EPA
 United States Environmental Protection Agency
 Office of Ecosystem Protection and Remediation
 999 18th Street
 Denver, Colorado 80202
 (303) 312-6236
 www.epa.gov / regionS
USDA
 United States Department of Agriculture
 Natural Resources Conservation Service
 655 Parfet Street, Room E200C
 Lakewood, Colorado 80215-5505
 (303) 236-2886
 www.co.nrcs.usda.gov
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities
on the basis of race, color, national origin, gender, religion, age, disability, political beliefs, sexual
orientation, and marital or family status. (Not all prohibited bases apply to all programs.) Persons with
disabilities who require alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD).
To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room 326W,
Whitten Building, 14th and Independence Avenue SW,-Washington, DC 20250-9410, or call
(202) 720-5964 (voice and TDD). USDA is an equal opportunity provider and employer.

-------