05/05/1993 - Packet AGENDA
NPO #3 MEETING
WEDNESDAY, MAY 5, 1993 - 7:00 P.M.
TIGARD CITY HALL
13125 SW HALL BLVD.
TIGARD, OREGON
City of Tigard
JOINT MEERNG WITH NPO #7 FOR THE FOLLOWING:
• PROPOSED WETLANDS INVENTORY AND ESEE ANALYSIS
MATERIAL ATTACHED -Pfesentation and Discussion
Duane Roberts, City Staff
ADJOURN TO REGULAR MEETING
1. CALL TO ORDER
2. ROLL CALL: PORTER BISHOP FROUDE
GARNER HANSEN HELM
MORTENSEN
3. Approve Minutes from April 7, 1993 meeting (not attached).
4. Review Notices of Decision received.
5. Other Business.
6. Adjournment
TO ENSURE A QUORUM TO CONDUCT BUSINESS, PLEASE CALL LIZ NEWTON AT
639-4171, EXTENSION 308 IF YOU ARE UNABLE TO ATTEND
April 28, 1993
Dear NPO Member:
The attached report was prepared as part of Periodic Review of
Tigard's comprehensive plan. It addresses certain state
requirements related to the inventory and protection of wetlands.
In particular, to complete Periodic Review, the city is required to
(1) inventory its wetlands and determine which are ecologically
significant, and (2) to develop a program to protect these
significant wetlands. Before developing this protection program,
the Periodic Review process requires that a jurisdiction balance
conflicting uses of specific sites. For significant wetlands that
have a potential conflict, such as wetland located on land
designated for industrial development, an economic, social,
environmental, and energy (ESEE) analysis must be undertaken to
determine which sites should be protected and which can be
developed. Under the provisions of Periodic Review, the sites that
should be regulated are those where the resource value outweighs
the conflicting use.
The City's current ordinaces pertaining to the regulation of
wetlands have been determined by DLCDC to be in compliance with
state law. The only shortcoming cited regarding these ordinaces
that is that they can only be applied to those wetlands clearly
defined as significant in an adopted inventory.
The staff study concludes that almost all the wetlands identified
in a comprehensive, city-wide inventory carried out in 1989 are
significant and should be protected from development. The only
wetlands not recommended for protection are certain small, seasonal
drainage ditches and small livestock and ornamental ponds that do
not drain into a stream system. These wetlands are not recommended
for protection because they have been judged to have negligible
wetlands value.
In summary, staff is seeking comments on its proposal that the City
Council adopt into the comprehensive plan the proposed inventory of
significant wetlands and new ESEE that recommends that all such
sites be protected.
Comments on this report are welcome. They should be directed to
Duane Roberts or Carol Landsman in the Long Range Planning
Division.
DRAFT
Appendix II
WETLANDS ESEE
This report provides background information pertaining to the
delineation and regulation of wetlands within the City of Tigard.
This information is provided in compliance with statewide goal 5.
This rule requires cities and counties to identify and adopt
programs to protect wetland and other natural and scenic resources .
Three specific steps must be followed to meet this goal :
1 . Inventory of the location, quantity, and quantity of
resource sites and the evaluation of their significance.
2 . Once a resource has been determined to be significant,
determination of whether any potential uses of the property
would conflict with the resource. If potentially
conflicting uses are identified, an ESEE analysis must be
conducted. ESEE stands for "economic, social, environmental
and energy. "
3 . After the ESEE analysis has been conducted, there are
three options for dealing with the site: protect the
resource fully and do not allow any conflicting uses, allow
the conflicting use to occur, or limit the conflicting use.
(1) INVENTORY PROCESS
Scientific Resources, Inc. (SRI) , a private consulting firm
specializing in wetlands research, has identified and assessed
wetlands within the City of Tigard. During summer and autumn of
1989, data and observations were collected to sufficiently
characterize the size and composition of each wetland area, and a
Wetland Wildlife Habitat Assessment (WWHA) was conducted for each
wetland area/system identified. The overall purpose of the study
was to produce a comprehensive, city-wide treatment of the
extent, location, and habitat value of the wetland resources
within the City.
SRI identified a total of 116 individual wetlands totaling
approximately 281 acres of potentially regulated jurisdictional
wetland (Figure 1) . The distribution of these wetlands is
closely associated with the existing network of drainageways .
Fanno Creek is the dominant stream system. It follows a north to
south flowing course from its headwaters in the West Hills to its
mouth at the Tualatin River. It is fed by two major tributaries,
Ash Creek, flowing from the northeast and Summer Creek, which
flows from the west . Wetlands along Fanno Creek and its major
tributaries are relatively long and narrow and are limited to the
floodplain by topographic features (e.g. , terraces and levies and
COMPREHENSIVE PAN
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Several small wetland areas are located along three minor
tributaries of Fanno Creek. One small stream flows south
directly into the Tualatin River along the southern border of the
study area. Where Highway 217 crosses Ash Creek and Red Rock
Creek, several relatively large wetlands have been extended and
enhanced with ponds . The Tualatin River floodplain, at Cook
Park, has contributed to the formation of several wetland areas
also.
The identification of these wetlands was carried out in several
phases . These phases included a review of color aerial
photography, intensive study of detailed topographic sheets,
identification and compilation of both hydric soils only and all
soil types found in the study area, review of 100-year floodplain
maps, significant natural resources, parcel base/tax lots, and
topographic quarter-section maps, and National Wetlands Inventory
maps.
In addition to collecting data for input to the WWHA analysis,
field observations were made on weather conditions, topography,
drainage, vegetation community composition and species dominance,
and human activities. The boundaries of each potentially
regulated wetland were then refined using the site specific
observations made.
The WWHA was conducted and qualitative descriptions were made of
each wetland area. There were two parts to the WWHA methodology:
1) a narrative description of the site; and 2) a numerical rating
of various wildlife habitat parameters to identify the potential
a given site has for wildlife. A host of habitat and wildlife
observations were made. These included:
1 . A description of the location of the WWHA unit,
2 . An approximation of the size of the WWHA unit,
3 . Comments regarding the reasoning behind specific numeric,
ratings or for potential of the site for rehabilitation,
4 . Seasonality of water features,
5 . Visual observation of water quality,
6 . Proximity of water to cover,
7 . Water type diversity,
8 . Wildlife food variety,
9 . Wildlife food quantity
10 . Wildlife food seasonality is a measure of food on a
year-round basis,
11. Structural diversity of cover,
12 . The variety of cover types.
The individual scores among the various habitat components, were
summed to arrive at a final score for a given site. Depending on
the final site score, a class was assigned to the site with
classes representing a predetermined range of habitat quality.
The classes, from I through IV, in decreasing order of habitat
quality (Class I the highest, Class IV the lowest) are defined
as:
Class I 76-96 (High value)
Class II 59-75 (Mod. high value)
Class III 34-58 (Mod. low value)
Class IV 0-33 (Low value)
The table below shows the number of acres in each wetlands class.
Class 2, with 115.4 acres, contains the largest number of acres,
while Class 4, with only 14 . 6 acres, is by far the smallest
wetlands class .
Wetland Class Acreage
1 56 .2
2 139 .5
3 71 .3
4 14 .6
TOTAL 281 .6
EVALUATION OF SIGNIFICANCE
The SRI WWHA assessed only the relative value of wetland for
wildlife habitat. Wetlands serve many other valuable social and
ecological functions as well. These other functions include
controlling flooding and storm water runoff by storing or
regulating natural flows; protecting water resources by filtering
out water pollutants, processing biological and chemical oxygen
demands, recycling and storing nutrients, and serving as settling
basins for naturally occurring sedimentation; providing areas for
groundwater recharge; providing open space and visual relief from
development in urbanized areas; and providing recreation
opportunities .
Many of these other values associated with wetlands are evident
in Tigard. For example, the preservation of wetland and other
open drainage areas contributes importantly to regulating storm
water runoff in the City. As mentioned in the Tigard Master
Drainage Plan, failure to maintain the City's wetlands will
increase the public cost for storm sewers, channels, and
culverts. Of related significance is the biofiltration value of
the City' s wetlands. This function is particularly noteworthy
because of the high levels of stream pollution found in the
Tualatin River. Illustrative of these high levels is that Tigard
is one of eleven jurisdictions involved in a recent court decree
directing the State Department of Environmental Quality (DEQ) to
establish limits for ammonia and phosphorous discharged into the
Tualatin. An important part of the plan to meet these new limits
includes protecting the "physical and biological integrity of
wetlands" because of the pollution control benefits they provide.
Tigard-area wetlands also are being used as educational resources
for students and the community. An outstanding example is the
some 20 acres of wetland found on the campus of Fowler Middle
School . These wetlands and the natural areas surrounding them
are the focus of an environmental learning center established in
1992 .
Even wetland areas with the lowest WWHA rating based on wildlife
habitat functions are described in SRI field notes as having some
value for wildlife. Moreover, with the few exceptions noted
below, all of the sites regardless of class have the potential
for natural area restoration and upgrading. Such restoration has
occurred in four cases since 1991 and additional enhancement work
currently is underway.
Because Tigard's wetlands are valuable and fragile natural
resources, almost all of the identified wetlands are significant
and are worthy of inclusion in the ESEE analysis. An exception
to this assumption are two small seasonal ditches and six small
artificial ponds that have no inlet or outlet and have little or
no value as wildlife habitat (Figure 1) . These areas are
identified in the following table with a brief description. They
occupy a combined total of only 3 .7 acres. They are designated
as not significant because they play no role or function as
wetland areas .
Wetland Size Ac Description
B13 0 .29 low area between two roads
C10, 11 0 .45 seasonal ditch and swa e
F13, 14 0 .90 goit course ponds
F , residential ponds
F1, 12 10 .78 111vestockponds
(2) CONFLICTING USES
The Goal 5 administrative rule requires an ESEE analysis to weigh
the importance of a resource site and the value of the site for
other land uses . The outcome of the ESEE analysis is a
recommendation to resolve the conflicting uses. A conflicting use
is one which, if allowed, would negatively impact a Goal 5
resource. This section discusses general ESEE consequences as
related to wetlands .
Economic Consequences
The economic consequences of protecting, or not protecting,
wetlands is related to drainage costs, public infrastructure
costs, site development costs, and property values. It also is
directly related to the loss of land zoned for residential,
commercial, and industrial development.
Many wetland sites in the City include natural drainage ways that
are part of the City's storm drainage system. If these sites
were filled, the construction and maintenance costs for storm
sewers, channels, and culverts to handle storm water runoff would
be expensive and would accrue to developers and the City.
The loss of the filtering and settling function of wetlands would
be costly to the community with respect to achieving federally
imposed water quality standards . Because the pollution of the
Tualatin River currently is above allowed levels, any loss of
these natural treatments processes would have to be compensated
for by mechanical and chemical methods .
Another factor in assessing the economic consequences of
protecting, or not protecting Tigard's wetlands is the effect
this decision would have on the availability of land zoned for
residential, commercial, and industrial development in the City.
Approximately 128 acres of wetlands in the study area are located
within areas designated for residential development. Protecting
these wetlands would diminish the supply of land available for
residential construction. But measured against the City's total
inventory of vacant residential land, estimated at 3, 607 acres in
a 1989 survey, the effect of this loss would be relatively
negligible. The consequences in terms of the loss of developable
housing units would be negated to an additional extent by the
Comprehensive Plan policy allowing 25% of the density on the
unbuildable portions of lots containing sensitive lands to be
transferred to the buildable portion.
While sufficient buildable land exists for residential
development, the supply of land available for commercial and
industrial development is less adequate. The diminishing supply
of land available for commercial and industrial development is
identified in the Tigard Comprehensive Plan as one of the core
problems facing City economic development. As of 1989, the
City's supply of commercial and industrial land was estimated 159
and 170 acres, respectively. Data on wetlands associated with
these acerages is shown below.
Study Inventoried Acreage
Area Wetlands with
Conflicting Uses
B Commercial - B7, 9, 19 .53
11, 12, 14, 15, 16
Industrial- E3, 4, 17 .32
15, 16 (36 .85)
E Commercial 41. 65
-E5, 6, 9, 10
, 11, 12, 13, 26, 27, 28,
29
26 . 9
Industrial- (68.55)
E5, 14, 15,
16, 20, 21, 22, 23, 24, 2
5, 30, 31, 32, 33
G ! Industrial- G1-14 j38 .2!71
Given the limited supply of vacant land zoned for commercial
retail and industrial development, the protection of the 140
acres of wetlands that are part of the inventory of these lands
would have a significant impact on the potential for commercial
and industrial growth. Mitigating this impact to some degree is
that ample room for commercial and industrial growth and
expansion is available on a regional basis. This is important
because the City economy is an integral part of a regional
economy involving all of the communities located within the
Portland metropolitan area. Fully three-fourths of employed
persons living in Tigard work outside the City. Many Tigard
enterprises are subcontractors and suppliers to businesses
located in other metropolitan area jurisdictions. Although the
protection of Tigard's wetlands is a disadvantage relative to
attracting new and expanded development to Tigard, the placement
of new industry/commerce in any jurisdiction within the region
can benefit the City by creating job opportunities for local
residents and increasing the market for locally based goods and
services.
Protecting the City's wetlands may have a negative effect on
individual property owners by decreasing the development
potential of property and, in some cases, by increasing
development costs . Protection may increase development costs by
requiring more site planning and design to incorporate natural
features into the site. However, since state and federal
regulations already preclude the development of wetland areas,
the direct economic impact of City regulation is limited to the
current City requirement that prohibits development within 25
feet of any wetland. Although this locally-imposed requirement
places a burden on individual property owners, the requirement is
necessary to protect the water quality functioning of Tigard's
wetlands .
Social Consequences
Protecting wetlands within the City provides recreation, a more
livable city, open space, wildlife habitat, waterways, and scenic
vistas. Wetlands offer scientific and educational opportunities .
Wetland protection also is a beneficial urban design element, and
improves the image of the city as a livable place.
Environmental Consequences
Protection of Wetlands would help maintain the existing diversity
of the natural environment and maintain connections to larger
natural areas outside the City. Protection of Wetlands would
preserve or enhance these functions and values : wildlife
habitat; water quality, erosion protection, flood control;
diversity of plant life; and education and research
opportunities .
Energy Consequences
The only known energy costs would be those associated with site
development improvements, mitigation, flood damage clean-up, and
the energy consumed by the commute to see wetland resources .
(3) PROGRAM DEVELOPMENT
Because the functions they provide outweigh the conflicting uses
described in the ESEE, the option recommended for dealing with
Tigard's wetlands is to protect all of the wetland areas
identified as significant and not allow any conflicting uses .
The protection program proposed consists of the current
provisions of the Tigard Community Development Code pertaining to
wetland areas. These provisions have been determined by DLCD to
meet Goal 5 requirements.
DR/ESEE
April 28, 1993
on the indicates deletion indicates addition, subtitles excepted
COMPREHENSIVE PLAN
3.2 FLOODPLAINS
FINDINGS
o To protect the intent of the City's Greenway policy, the Greenway is
defined with the same physical boundaries as the 100-year flood plain
boundary.
o Scientific Resources, Inc., a private consulting firm specializing in
wetlands research, has identified and assessed wetlands within the City of
Tigard.
o Wetlands serve many valuable social and ecological functions. These
include providing habitat for wildlife, controlling flooding and storm
water runoff, filtering out water pollutants, recycling and storing
nutrients, serving as settling ponds for naturally occurring
sedimentation, providing areas for groundwater recharge, providing open
space and visual relief, and providing recreation opportunities.
POLICIES
3.2.4 THE CITY SHALL REQUIRE THE DEDICATION OF ALL UNDEVELOPED LAND WITHIN
THE 100-YEAR FLOOD PLAIN PLUS SUFFICIENT OPEN LAND FOR GREENWAY
PURPOSES SPECIFICALLY IDENTIFIED FOR RECREATION WITHIN THE PLAN.
3.2. (4]5 THE CITY SHALL PROHIBIT DEVELOPMENT WITHIN AREAS DESIGNATED AS
SIGNIFICANT WETLANDS GN THE I'LOGDPLAIN—AND W2q%A?1PG MAP IN THE
"WETLAND INVENTORY AND ASSESSMENT FOR THE CITY OF TIGARD"
(SCIENTIFIC RESOURCES INCORPORATED, 1990) . NO DEVELOPMENT SHALL
OCCUR ON PROPERTY ADJACENT TO AREAS DESIGNATED AS SIGNIFICANT
WETLANDS 9N THE—FL96DPLAI?; 2VJD i Bg1LA?4DS �f P IN THE "WETLAND
INVENTORY AND ASSESSMENT FOR THE CITY OF TIGARD" (SCIENTIFIC
RESOURCES INCORPORATED, 1990) WITHIN TWENTY FIVE (25) FEET OF THE
DESIGNATED WETLANDS AREA. DEVELOPMENT ON PROPERTY ADJACENT TO
SIGNIFICANT WETLANDS SHALL BE ALLOWED UNDER THE
SENSITIVE LANDS SECTION OF THE CODE.
3.4.1 THE CITY SHALL DESIGNATE, BY DEFT IEP1 N NE)T BY LOCATION, THE FOLLOWING AS
AREAS OF SIGNIFICANT ENVIRONMENTAL CONCERN.
a. SIGNIFICANT WETLANDS;
b. AREAS HAVING EDUCATIONAL RESEARCH VALUE, SUCH AS GEOLOGICALLY
AND SCIENTIFICALLY SIGNIFICANT LANDS; AND
C. AREAS VALUED FOR THEIR FRAGILE CHARACTER AS HABITATS FOR
PLANTS, ANIMAL OR AQUATIC LIFE, OR HAVING ENDANGERED PLANT OR
ANIMAL SPECIES, OR SPECIFIC NATURAL FEATURES, VALUED FOR THE
NEED TO PROTECT NATURAL AREAS.
DR/Code
April 28, 1993