Wetlands 8e Watersheds Unit

Boulder Creek Furnishes Laboratory for NPS

Treatment

The Boulder Creek Enhancement Project, designed to evaluate a new approach to water quality cotrol,
provides a complete laboratory to test the feasibility and effectiveness of combining off-site nonpoint
source treatment with traditional point source treatment to achieve water quality goals.

In the mid-1980s, the City of Boulder faced increased regulation of its wastewater treatment plant
(WWTP) under state National Pollutant Discharge Elimination System permitting requirements,
which protect the designated uses of receiving waters.

The Boulder Creek Enhancement Project's overall goal is to find out how best management practices
can improve stream quality when used with traditional point source treatment at a publicly owned
treatment works. The project investigates techniques to stabilize pH and temperature fluctuations and
to reduce turbidity and un-ionized ammonia in the creek's main stem section. The project compliments
the city's conventional wastewater treatment plant. Early attempts to construct a dynamic computer
model of the Boulder Creek system showed that a full-scale demonstration project was the only practi-
cal means to test the effect of channel modifications, revegetation, and erosion control on in-stream
quality and habitat.

Two specific project goals are:

1.	To verify basic assumptions about how enhancing the riparian habitat affects the water

quality.

2.	To verify the cost, constructability, and durability of BMPs.

BMPs	that address each site's specific problems vary according to its current land use:

•	Cattle exclusion (fencing),

•	Bank stabilization,

•	Channel modification (thalweg pools),

•	Recreation,

•	Wetland enhancement, and

•	Planting of riparian vegetation.

The Boulder Creek project is transferable to other streams requiring similar treatment. Riparian restora-
tion that can provide multiple benefits to wildlife, water quality, and property owners can increase the
effectiveness of existing traditional treatment facilities.

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