FLOOD04566

• County: Boulder
• Community: Boulder
• Stream Name: Gregory, Bear Can, Bluebell Can Creeks, Viele Chan
• Basin: South Platte
• Title: Major Drainageway Planning Volume 1, Part C
• Date: 9/1/1970
• Prepared For: Boulder County
• Prepared By: CWCB
• Floodplain - Doc Type: Floodplain Report/Masterplan

I

33

I

SECTION V

I

LEGA L AS PECTS

I

In the companion North Boulder Report, a section dealt with legal
opinions on the proposed drainage improvements. It was important to
develop the legal detai Is there because it was a pi lot study. The
same basic drainage law appl ies to South Boulder.

I

I

Mr. Joe Shoemaker of Denver, an urban drainage legal specialist, was
retained for a review of these new potential drainage improvements
in South Boulder during the spring of 1970. A field trip with him
and Dr. John Sheaffer of Chicago was made over the routes prior to
choosing alternates. Their opinions and consultations were helpful
in this assignment.

I

I

For urban drainage planning and design, the legal aspects of urban
drainage are of key importance. An improperly planned and designed
artificial waterway can expose a city or county to significant I ia-
bilities should the waterway fail.

I

In urban drainage pianning, it is essential to keep in mind that a
reasonable frequency of occurrence of storm runoff must be chosen for
practical and economical reasons. It is well known, and it happens
all too often, that a storm may occur over the basin much larger, and
having greater intensities, than that used for design purposes. Thus,
the matter of overtopping or failure of the channel works is a possi-
bility on all urban drainage faciiities.

I

I

I

Flood hazards with urban drainage works are often associated with im-
poundment reservoirs which, when topped, may fail and cause a surge
of water much larger than the rate of flow which would have occurred
under natural means. It is for this reason that impoundment reser-
voirs, when associated with urban drainage works, are planned and de-
signed in a manner befitting their damage potential.

I

I
I,

The choosing of routes for waterways in already urbanized areas pro-
vides temptations to the engineer to choose routes which the natural
flood waters would not follow if left to follow the downhi II course,
obeying the law of gravity.

I

This storm drainage pilot planning study has made it clear that master
planning of urban drainageways must be undertaken with the environ-
mental design team approach with full consideration being given to the
opinions of an attorney qual ified in urban drainage matters.

I

Pertinent quotations from Mr. Shoemaker's 1969 opinions are presented
below. The reader is directed to the April, 1969, Report for their
full context.

.

"We are dea ling here with the proper method of hand 1 i ng

I