DOLORES RIVER WATERSHED EVALUATION
&
RECOMMENDATIONS REPORT

For the TOWN OF RICO
In DOLORES COUNTY, COLORADO

Prepared for:
TOWN OF RICO AND THE
COLORADO WATER CONSERVATION BOARD

Prepared by: Matrix Design Group, Inc.
1601 Blake Street, Suite 200
Denver, Colorado 80202
(303) 572-0200
Fax (303) 572-0202

September 30, 2004

Table of Contents

Cover Pages (141KB)

CHAPTER 1: Introduction and Background (49 KB)
    Background
    Watershed Issues
    Guiding Principles
    Scope of the Project

CHAPTER 2: Reach Descriptions (539 KB)
    Reach A: County Boundary to Spruce Gulch
    Reach B: Spruce Gulch to Below Town
    Reach C: Below Town
    Reach D1: Town Lower Reach – Rico Boy and Santa Cruz Mines
    Reach D2: Town Lower Reach – Pasadena Smelter
    Reach D3: Town Bridge and Columbia Tailings Cap
    Reach D4: Downstream of Silver Creek
    Reach D5: Highway Bridge to Silver Creek
    Reach E: Highway Bridge to St. Louis Ponds
    Reach F: St. Louis Ponds
    Reach G: Chutes
    Reach H: Town Well
    Reach I: Silver Creek
    Exhibit 2.1 Study Reaches (1.3 MB)
    Exhibit 2.2 Dolores River Profile (393 KB)

CHAPTER 3: Environmental Issues (99 KB)
    Background
    Summary of Environmental Investigations
        Environmental Protection Agency Investigations
        Wash Environmental Phase I and Phase II
        ARCO VCUP/NAD Program
        Titan Geologic and Geochemical Investigations
        CDPHE and ARCO Lead Characterization
        Treatment Alternative St./ Louis Ponds, Masters Thesis
        CDPHE Water Quality Assessment
        U.S. Fish and Wildlife Service Memorandum
        CDPHE Brownfield’s Assessment
        ARCO Residential Soils VCUP program
    Relevant Findings
        Environmental Concerns by Reach

CHAPTER 4: River and Floodplain Issues (109 KB)
    Dynamic Equilibrium
    Defining Channel Instability
    Shear Stress
    Bedload Sediment Transport
    Basis for Channel Stabilization
    Causes of Instability
    Flood History and Gage Records
    Floodplain Studies
    River Issues
    Exhibit 4.1 Current River Issues (3.5 MB)
    Exhibit 4.2 Potential Future Changes (3.3 MB)

CHAPTER 5: River Recreation and Habitat (766 KB)
    Fishing and Trout Habitat
        The Dolores River Fishery
        Existing Habitat Degradation
        Stream Development Projects
        Effects on Spawning Trout
        Spawning Seasons and Habitat
        Construction Practices and Spawning
    Recreational Value of the Dolores River
        Fishing
        Boating
        Planning for River Access and Use
    Vegetation and Riparian Habitat
        Functions and Values
        Critical Areas
        Recommendations to Preserve Critical Reaches
        Buffer Zone Recommendations
        Wildlife Protection Zones
        Elements and Standards of a Healthy Aquatic Ecosystem

CHAPTER 6: Potential River Restoration (620 KB)
    Channel Stabilization
    Approaches to River Restoration
    Types of Stabilization
    Hard Controls
        Rock Riprap
        Spurs, Dikes, Deflectors, Hardpoints, Groins, Vanes
        Grade Control Drop Structures
    Soft Controls – Bioengineered Treatment Functions
        Stream Stabilization Alternatives
        Selecting the Best Alternative Bioengineered Treatment
        Effectiveness of Treatments
        Maintenance of Bioengineered Treatments (Watering and Weed Control)
    Previously Proposed Improvements
    Additional Proposed Improvements
    Implementation
        Public Involvement
        Enlisting Expertise
        Funding
        Next Steps
    Exhibit 6.1 Summary of Previously Proposed Issues and Improvements (4.8 MB)
    Exhibit 6.2 Possible River Improvements (3.2 MB)

REFERENCES (33 KB)

LIST OF FIGURES:

• Exhibit 2.1 Study Reaches (1.3 MB)
• Exhibit 2.2 Dolores River Profile (1.3 MB)
• Exhibit 4.1 Current River Issues (3.5 MB)
• Exhibit 4.2 Potential Future Changes (3.3 MB)
• Exhibit 6.1 Summary of Previously Proposed Issues and Improvements (4.8 MB)
• Exhibit 6.2 Possible River Improvements (3.2 MB)