WSP01414

• File Number: 8449.918
• Description: South Platte Projects
• State: CO
• Basin: South Platte
• Date: 8/1/1982
• Author: CWCB
• Title: South Platte River Basin Assessment Report
• Water Supply Pro - Doc Type: Publication

Invertebrates

This group includes insects, spiders and other arthropods that are

extremely abundant in the vegetation types of the South Platte River

basin. One insect species, the Pawnee montane skipper butterfly, is rare

and the only known population of this species occurs in a 12-mile section

of canyon bottom of the South Platte River between Douglas and Jefferson

Counties, Colorado (Figure 1).

Human Population

The combination of climate and abundant natural resources is responsible in

part for the rapid growth of human population within the SOuth Platte River

basin. Much of the population growth of the last 2 decades has occurred in

the foothills and suburban areas around Denver. on the other hand, several

rural communities, particularly in the eastern Plains zone of the basin,

have lost population between 1960 and 1970 (Toups Corporation, 1975).

Preliminary population figures from the 1980 population census showed that

the basin's growth increased from nearly 1.48 million in 1970 to

1.96 million in 1980 (Colorado Division of planning, 1980). For counties

in the basin, the average percentage population increase for the period

from 1970 to 1980 was 32.3 percent, compared to the entire statels

population growth of 30.2 percent during the same period. The population

of many suburban and foothills communities increased substantially during

this period; whereas, the City and County of Denver actually lost

population. Eastern rural counties in the basin also recorded small

population gains from 1970 to 1980 compared to population losses in several

cases from 1960 to 1970 (Table 1).

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