Asfpm 2005 Multi Use Greenways With Nai

Colorado Examples

John Pflaum, P.E.

ASCG Incorporated

Cindy Thrush, P.E.

Urban Drainage & Flood Control District

with no Adverse Impact

Denver Metropolitan Greenways

Born from a Flood

Evolution Of Denver’s Greenways

1965 Major Flood with Millions in Damages

1969 Urban Drainage & Flood Control

District Forms

1973 Significant Flood

1974 Platte River Development formed

1976 Initial Confluence Project Completed

1976 to 1996 South Platte River Greenway

Extended North & South

1980’s to Present – Greenways Developed

along Tributary Drainageways

1996 to Present – Second Wave of South

Platte River Greenway Improvements

(Downtown Riverfront and Suburban

Greenways)

The Urban Drainage and Flood Control District and

Public Agency Partnering

Who is the Metro Denver Urban Drainage

and Flood Control District?

Quasi-governmental agency established by the

Colorado State Legislature in 1969 to assist local

governments in 6 counties, 34 cities with multi-

jurisdictional drainage and flood control projects.

Who is UDFCD? Continued

Governed by 20 member Board Of Directors

18 – Elected Officials

2 – Professional Engineers

Budget is about 15 million each year, funded by

property taxes. 20 full time staff, all engineering

design, project construction and maintenance

work contracted out to private industry.

MAJOR AREAS OF ACTIVITY

Drainageway Maintenance

Capital Improvement Projects

Master Planning

Floodplain Management

Flood Warning

NPDES Permitting - Storm

Water Quality

Criteria Development - Manuals

Floodplain Preservation

New Development Plan Review

6 Counties

1,608 square miles

1,600 miles of

major drainage ways

Map of UDFCD

Boundaries

Denver Drainageway

Characteristics

Semi-arid climate, 15 inches of rain per year

Most erosion and flooding due to thunderstorms

Only 6-8 creeks have more than 5 cfs base flow

About 95% are natural open channels (only a small portion contained by levies)

Elevation: 5,280 ft – “Mile High City”

Population 2.2 Million

Partnering on Trail Projects

for Over 35 Years

Work with Cities, Counties, Park Districts

Maintenance access trails proposed in Drainageway Master Plans since the 70’s

Drainageways platted in separate tracts of land dedicated to Park Districts or HOAs

Denver area’s network of trails is linked together through the drainage ways

Many projects have combined stream restoration and trail construction/maintenance together

UDFCD Trail Participation Policy

Trail must serve a maintenance access need for a

drainage way

Right-of way, design, construction and restoration

maintenance eligible for funding

Participation limited to 50% of the design and

construction cost for a “soft” surface trail, or 25%

of a concrete trail

Design must be reviewed by UDFCD, either party

can manage the project

Planning and Designing Greenways

Planning:

Identify watershed, jurisdictions, land ownership

Involve public

Continuity, connectivity, accessibility

Resource preservation and protection

Floodplain and geomorphology

Buffering, vistas, views

Education and stewardship

Signage and way-finding

Multiple use benefits

Safe and maintainable

Planning

and Designing Greenways

Design:

Multi-Disciplinary Team

Public officials/representatives

Engineers

Surveyors

Landscape Architects

Ecologists

Biologists

Right-of-way agents

Trail & Greenway Routing Considerations No Adverse Impacts To Floodplain

Minimize Impacts to Stream Riparian Areas

Trail Grading to Avoid or Minimize Floodplain Impacts

South Platte Greenway at Commons Park

Sand Creek Greenway

Stream Crossings

Bridges

Low Flow Crossings

Informal Boulder Step Crossings

Must be designed to withstand flow velocities during storm events

Low Flow Crossings

Prefab. or Reinforced Concrete Construction

Fixed or Collapsible Handrails

Erosion Protection at Corners

Often Combined with Channel Stabilization Measures

Goldsmith Gulch at Bible Park Grange Hall Creek

Appropriate for Wide Floodplain Conditions

Designed for Overtopping

Big Dry Creek Greenway

Cherry Creek

Bridges

Span 100-yr. Floodplain

Durability/Low Maintenance

Safety and Rub Rails

Concrete Deck Preferred

Cherry Creek

Centennial Bridge over

Cherry Creek

at Confluence Park

16th Street Bridge over South

Platte River Downtown Denver

South Platte River Greenway at

Cuernavaca Park

Big Dry Creek

Trail Connection

Underpasses

Safe Grade Separation from Vehicles

Often Inundated Several Times per Year

Ramp to Street Grade Desirable

• Safe Route During Flooding

• Access Point for Public & Maintenance

Separate Underpass Structures

• More Costly, but:

• Separated from Streamside Environment

• Can Provide Supplemental Flood

Capacity

Big Dry Creek Tail Underpasses

Sand Creek Greenway

Willow Creek at

Dry Creek Road

Summary Sensitive Routing – Avoid Fills

Be Creative to

Overcome

Problems

Encourage Citizen Participation

Celebrate your Success!

Happy Trails!