HomeMy WebLinkAbout2001-10-02; City Council; 16381; South Carlsbad Village Storm Drain Project4B# /d,3bi
MTG. 1 o/2/2001
3EPT. ENG
STATUS OF PUBLIC OUTREACH PROGRAM FOR THE
VISTAKARLSBAD INTERCEPTOR SEWER REACHES VCSB
THROUGH VC11 A, PROJECT NO. 3182, THE SOUTH
RECOMMENDED ACTION:
This is an informational item and theretore there is no staff recommendation at this time.
ITEM EXPLANATION:
PROJECT OVERVIEW
This project replaces segments of the Vista/Carlsbad interceptor Sewer, constructs the South
Carlsbad Village storm drain, and resurfaces streets along the project alignment. The alignment of
the pipelines and streets to be owrlaid are shown on the attached Exhibits 1 and 2.
City staff and Katz and Associates will provide the City Council with updates on construction status
as well as the Public Relations Program.
FISCAL IMPACT:
This is an informational item and there is no fiscal impact at this time.
ENVIRONMENTAL IMPACT:
Not applicable.
EXHIBITS:
Exhibit 1: Sewer and Storm Drain Alignment
Exhibit 2: Pavement Overlay Locations
EXIilING SEWER \ Y - ----
XFFERSW JRmE b FREEVAY CROSSUS
LOCATION MAP
JISTA / CARLSBAD INTERCEPTER SEWER
ID SOUTH CARLSBAD STORM DRAIN PROJECT
CONTRACT
#3182/3528
.EFFmsut RIDGE b FREVAY CmssDdG
LOCATION MAP
Project nme :
PAVEMENT CIVERLAY
on 1L3~7
v.3~-3-0 1
it&W. (Q
NEGATIVE DECLARATION
For Approval of Amendments to the Land Use and
Circulation Elements of the General Plan and Zoning Ordinance
Request for Public Comments on GPA Ol-Ol/CZA 01-03, Livable Streets.
Mr. Gary Wayne
Planning Department
City of Carlsbad, CA
Dear Mr. Wayne, 9 October 2001
The proposed amendments (GPA Ol-Ol/ZCA 01-03) promoting “Livable
Streets” is a great step in the right direction, by reducing street widths from 40 ft to
34 ft, but it unfortunately eliminates streets with 32 ft, 30 ft, and 28 ft and requires
curbs. The proposed Negative Declaration should be rejected and proposed
amendments should be revised based on the availability of new information as
summarized below. My concern is based on a new model that correlates the percent
of impervious cover in a watershed and stream condition. The model indicates that
the threshold for maintaining urban stream stability occurs at about 10%
impervious cover.
1.
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8.
9.
It is self-evident that as the percentage of impervious cover in a watershed
increases, that stormwater runoff increases. We also know that stormwater
runoff can impact streams.
The road related impervious cover at 11 residential, multifamily, and
commercial areas measured in Olympia, WA accounted for -65% of the runoff;
rooftops accounted for 35%. But conventional zoning is based on rooftops (i.e.
population density), and is therefore a poor indicator of stream condition.
The total runoff volume for a one acre parking lot is about 16 times that
produced from a natural meadow.
Increased impervious cover directly translates into higher peak discharge rates,
greater runoff volumes, and higher flood plain elevations.
Local streets represent 50 - 65% of the length of the entire road network.
Infrastructure, primarily transport impervious cover, constitutes about 50% of
the cost of construction of a residential subdivision.
Conventional zoning standards tend to increase the size of lots and therefore the
distance between lots, hence, increase in road length.
Communities typically rely on large lot zoning and BMP’s, but large lot zoning
increases road length, and BMP’s do not always work well.
Although national design standards must be met for any road built with state or
federal funds, these design standards for residential streets are based on a one-
size-fits-all approach and tend to be over built.
10. Residential streets yield the highest concentrations of harmful bacteria.
11. Road length can be reduced by 50 - 75% and road width by 25 - 35% by
clustering development, and property values can increase 5 - 32% by adding
open space. Capital costs can be reduced by 10 - 33%. More room is made
available to locate more successful BMP’s.
12. Major problems in Orange County:
l The true scope of creek degradation may not be fully manifested at the
watershed level for many years.
l Artificial wetlands to treat a stream.
l High bacteria counts from a 1400 home residential development.
l Major stream erosion.
13. Conclusion:
l Reduce % impervious cover.
l Map current level of % impervious cover throughout the City and
watershed(s).
l Develop a steam protection strategy that is integrated into the entire
development cycle, from watershed-based zoning to its ultimate realization in
the design and construction of individual development projects.
Sincerely,
Alan B. Thum
1392 Peachwood Drive
Encinitas, CA 92024