HomeMy WebLinkAbout12/04/2001, 2 - SAN LUIS OBISPO PHASE II WATERWAY MANAGEMENT PLAN council
j acEnbA REpoRt
CITY OF SAN LUIS OBISPO
FROM: Mike McCluskey,Public Works Director
SUBJECT: SAN LUIS OBISPO PHASE II WATERWAY MANAGEMENT PLAN
CAO RECOMMENDATION:
1. Receive a presentation on the draft San Luis Obispo Phase H Waterway Management Plan.
2. Provide direction to staff on any changes to the proposed Plan in the areas relating directly to
the City of San Luis Obispo.
3.. Give feedback and comments on areas of the proposed Plan relating to locations outside the
City of San Luis Obispo.
DISCUSSION
Background and Status of the San Luis Obispo Phase II Waterway Management Plan
A. Floods of 1969 and 1973
These two storms awakened the community to the problem of flooding along the San Luis
Obispo creek system. During the post-war growth years the City had not experienced any
serious flooding problems and had not performed any significant maintenance of the major creek
system. The immediate response to the 1973 flood was the formation of Zone 9 of the County
Flood Control and Water Conservation District. This Zone of Benefit included the entire San
Luis Obispo Creek Watershed. It was formed with a primary responsibility to gather information
about flooding and to develop a plan to reduce or eliminate flood impacts.
Funding was also to be provided for minor maintenance of the waterway. Capital improvements
were not to be funded by the original tax levels. Originally, a .08% tax rate was established that
was to be reduced to .05% after five years. The approval of Proposition 13 froze the tax formula
and resulted in a continuing flow of tax dollars into the program. In the years since its formation,
Zone 9 has funded the Nolte Study of 1977, which recommended standards and projects to
reduce flooding. The recommended projects were a basis for the City's 1983 Flood Management
Policy (Pink Book). Funds in the County program were used each year to pay for clearing major
creeks and the repair of creek banks damaged by high flows in areas under public control.
Generally, funds for projects in the City and in the County were divided, with 80% going to the
City, since it represented about 80% of the funding source. Over time, the balance in the Zone 9
fund has increased. After the 1995 storms, the City was able to fund a major portion of a creek
bank repair program from the Zone 9 balance and Zone 9 funds were budgeted to pay for the
Questa Phase I and II studies being discussed at this meeting.
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Council Agenda Report-Waterway Management Plan -Phase II
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B. Pink Book Flood Management Policy—Adopted by Council June 1983
This document included policy information on design and construction standards for waterways,
storm drains and drop inlets, and listed a number of projects of varying scale to address points of
restriction to flood flows, as well as minor and major creek projects to increase capacity.
Many of the projects proposed were completed, with the main exception being the $20.5 million
in Major Waterway Modifications. Council funded some of the major projects, but ultimately
declined to approve final plans and specifications because of costs and environmental concerns.
C. 1995 Floods
The 1995 floods once again reminded the City of the flooding and bank instability problems
along the San Luis Obispo Creek. At that time, the Council had already adopted a goal to review
and update the "Pink Book'. Staff reductions of 1993, and permitting and environmental issues
related to flooding that occurred in 1995,prevented staff from accomplishing this goal.
In the summer of 1995, staff's application to the Army Corps of Engineers for permits to perform
flood damage repairs raised several "cumulative effects" and "downstream impacts" issues that
led to the Corps's requirement to perform comprehensive engineering and environmental studies
of the entire water shed. These studies revisited the Nolte Study and are now the basis for
proposed new City policies on Flood Plain Management and revised design standards for
drainage,bank stabilization, and flood control in the City.
In the fall of 1995, the Corps asserted discretionary authority over bank stabilization measures
within the San Luis Obispo Creek and its tributaries. The Corps' response to the City's permit
application was outlined in a letter dated April 30, 1996. It determined that each additional
project that would channelize or otherwise affect the creek would result in greater than minimal
cumulative impacts and require an individual permit (a costly and lengthy process). Instead, the
Corps recommended that the City submit a single individual permit application for a
comprehensive, long-term drainage plan for the creek.
The process was initiated with a Request for Proposals for a two-part study. The study was
broken into two parts because the City and Corps recognized in 1996 that the City needed to
repair certain high priority creek banks damaged in 1995 and that the entire study required by the
Corps would take some time. The first phase was an abbreviated study approved by the Corps
that covered only portions of the creek where permits for bank repair were needed immediately.
The Phase II portion of the study covers the entire San Luis Obispo creek and its major
tributaries, and will satisfy the Corp requirement for a comprehensive long-term drainage plan.
Questa Engineering was selected for both phases of the project following established City
procedures.
D. Annroval of Phase II Contract- 1999
Phase II of the study was approved to begin in late fall of 1999. It also had two parts. The first
was an aerial survey of the major creek system from the base of Cuesta Grade to the ocean. The
second was an engineering and environmental technical study. Information from the first sub-
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Council Agenda Report=Waterway Management Plan-Phase II '
Page 3
part was necessary before any real progress could occur on the second, since the information was
needed for development of new computer and hydrology models.
The City expanded the scope of the aerial work to include the entire City Urban Reserve Area.
The aerial work utilized LIDAR technology to determine elevation contours. This was an
efficient way to obtain solid information and avoid as much manual surveying as possible.
Unfortunately LIDAR technology is a very advanced form of survey with few vendors in the
country. The initial vendor was unable to perform due to equipment failure; therefore, another
vendor was brought in. The second vendor also had some difficulty, resulting in additional
delays in completion of the initial work.
Another delay in the project occurred when the County, because of a pending lawsuit, withheld
data from our consultant because another consultant owned it. Our consultant delayed pursuing
alternate methods of obtaining this data because the County told him that their data would be
available shortly. The County's data was significantly superior to any alternative data our
consultant could obtain and waiting made good sense.
The original schedule showed the project starting in November 1999 with completion in January
2002. At this time, the project is nearly a year behind schedule, with completion of all the work
now projected for fall 2002.
Completed Phase II Waterway Management Plan Tasks
1) Aerial photo and topography contour maps: The City and County have an excellent photo
of the waterway from the base of Cuesta Grade to Avila including See Canyon. The photo is
in color and has an extremely high resolution. There is also a topographic contour map with
%i meter contours of the waterway. Similar maps are in the City's possession for the entire
Urban Reserve area.
2) Watershed reconnaissance, inventory, hydrology and geomorphology: The raw data is in
the City and County's possession and is displayed for the public on a web site maintained by
Cal Poly. It will be included as appendices to the overall plan.
3) Computer Models: The hydrology and hydraulic models have been completed using
standard Corps of Engineers procedures.
4) Sediment Study: A special study was conducted following 2-dimensional modeling of
sediment transport problems at the Marsh Street Bridge and is completed.
5) Problem Identification: Two meetings were held with the public to discuss problems and to
identify missed issues. Solutions to problems were identified and are included in a
document.
Status of the Phase II Waterway Management Plan Documents
The following documents have been received and reviewed. Final versions are still forthcoming
except as noted.
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Council Agenda Report—Waterway Management Plan-Phase II
Page 4
1) Design Manual — Draft submitted. Currently undergoing additional edits. To be delivered
December 4, 2001.
2) Flood Elimination Plans — Three alternatives with costs completed. Alternatives to be
presented to Council on December 4, 2001.
3) Maintenance Plan — Completed. Now termed "Stream Maintenance and Management
Program.
4) Mid Higuera Flood Plan: - Final Document received and used by Community Development
in the presentation of the Mid Higuera Street Plan.
5) Stream Bank Stabilization Handbook—Completed; now a chapter in design manual
6) NPDES Plan for San Luis Obispo. Final Document received and accepted by Council.
7) EHZIEIS—Early stages; this piece of major work should be completed by April 2002.
The draft Waterway Management Plan Phase H brings all of the aforementioned tasks and
documents, except the EIR, into one summary plan document. The final document is scheduled
for completion in mid-December, based on Council direction at this study session. This
document will then be circulated for agency comments in.January 2002.
The Plan is well over 300 pages long. Therefore, it will not be placed in the Council reading file.
After the Study Session, if any council member would like to be more thoroughly briefed on any
one section or have their own copy of the document, staff will arrange to meet that request.
Areas for Discussion and Council Feedback
1) Design Manual - the Consultant will overview the following areas that will determine
how the City designs future improvements:
a) Design storm levels
b) No net fill concept and special zones
C) Possible Drainage Impact Fee
d) Possible channel conveyance design capacities for each reach (differs for each
reach and will be dependent on alternative selected)
2) Stream Management Program - the consultant will provide a brief review of the
following elements and seek Council comments and possible direction:
a) Current permit situation
b) Proposed permit streamlining
c) Vegetation management
d) Bank stabilization procedures
3) Flood Management Plan
a) Comparison of FEMA and Zone 9 model flows and Flood Zone Problems
b) Alternatives and their costs
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Council Agenda Report=Waterwaygement Plan-Phase H
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C) Bank stabilization program
FISCAL IMPACT
During this study session staff will review many variables. Depending on feedback from the
Council, the costs of implementation will vary. However, staff is independently working on the
establishment of a Storm Water Utility that will most likely fund most of the improvements and
programs called for by the Phase 11 Plan.
ATTACHMENT
Consultants and Participating Agencies
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Attachment
Consultants and ]Participating Agencies
Professional Consultants:
Lead Consultant: Questa Engineering Corporation
www.questaec.com
Biology Sub-consultant: Morro Group
www.morrogroup.com
Agencies participating in the study:
Government Agencies:
City of San Luis Obispo,www.ci.san-luis-obispo.ca us
County of San Luis Obispo—Zone 9
Agricultural Research Initiative(ARI) project,www.cagr.calpoly.edu/cagr/ari/
San Luis Obispo County—Planning Department
U.S. Army Corps of Engineers Regulatory Branch,www.spl.usace.army.mil/co/co5.html
National Marine Fisheries Service
California Department of Fish and Game
U.S. Fish and Wildlife Service
US Environmental Protection Agency
Central Coast Regional Water Quality Control Board,www.swrcb.ca.gov/rwgcb3/
Landscape Architecture Department Cal Poly San Luis Obispo, suntzu.larc.calpoly.edu/gislab/
BioResource &Agricultural Engineering Department Cal Poly San Luis Obispo,
www.calpoly.edu/—brae/
Coastal San Luis Obispo Resource Conservation District, www.coastalrcd.org
Non profit corporations: San Luis Obispo Land Conservancy,
http://www.slonet.org/vv/land—con/
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