HomeMy WebLinkAboutSWP272171(13) OCT-15-93 FRI 14:40 PARAMETRIX FAX NO, 206 889 8808 P. 01/05
Parametrix Inc.
5808 Lake Washington Blvd N.E. , Kirkland, WA 98033
Phone: 206-822-8880 Fax: 206-889-8808
FAX TRANSMUSSIOIN COVER PAGE
FAX # 206-889-8880
GC i 15 1993
Number of Pages (not including this page): Ci-� OF RENTON.
To: scoff Woodbury
Engineering pep
From: Tracey McKenzie
Receiving FAX Number: 235-2541
Date: October 15, 1993 Time:
Comments:
I am still working on the conditions assessment. However, as we discussed, it is important for
the City to review the opportunities and constraints that we've identified We should discuss
them on Monday so we are all in agreement about what should he presented to the public. I'll
bring maps with me on Monday to show you what we can prepare for Wednesday afternoon.
OCT-15-93 FRI 14:41 PARAMETRIX FAX NO, 206 889 8808 P, 02/05
Soil test pit 5 was excavated in an upland area and had a similar profile to test pit 4. Fill
occurred from the surface to 2 ft 8 inches. The historic A horizon was observed below the fill
and extended 12 inches below the fill, Clay was the dominant soil below the historic A horizon.
Black sand was observed at 10 ft 4 inches. The sides of the soil pit were glistening and seepage
was evident at 8 ft.
5.3.2.3 Hydrology
The source of hydrology for the existing wetlands is primarily precipitation. Wetlands on this
site lack an obvious inlet or outlet source. Saturation to the surface and inundation to a depth
of 1 inch were observed by Jones and Stokes (1993) in the emergent wetland areas. On the day
of the site visit in July 1993 inundation and saturation were not observed in the forested portions;
however, wetland hydrology was assumed based on depressional topography, soil characteristics,
and bare ground.
The functional values associated with these wetlands were rated as low by Jones and Stokes
(1993) and David Evans and Associates (199) due to the size of the wetlands, lack of structural
and community diversity, and an isolated and disturbed nature. The wetlands are extremely
limited in providing sediment trapping, food chain support, and groundwater recharge and
discharge. The wetlands and depressional topography provide some flood storage and wildlife
habitat. The limited young forested and shrub canopy layers provide some cover for small
mammals and birds,
5.3.3 ortunities
Using the results of the analysis of existing information and the field investigation the
opportunities and constraints associated with establishing wetlands on the mitigation sites was
prepared and are presented below.
The natural ecosystems in the valley have been severely altered through the years by
development. Reestablishing wetlands on the mitigation sites provides an excellent opportunity
for the City to gain wetland acreage in a floodplain area where the added physical functions of
stormwater attenuation and biofiltration will achieve the highest value.
The mitigation program is a great opportunity for the City to demonstrate that wetland mitigation
is feasible and to assist in furthering the concept and teehn:ical and administrative approaches of
mitigationr3g. The fact that the City, as a local sponsor, is committed to establishing a
mitigations program that is based on public and private partnerships indicates that the City
is on the cutting edge of demonstrating the feasibility g of miti ation=<:.� k r The mitigation
program is also an excellent opportunity to develop the framework fore in the currently
conceived form of a demonstration project that is relatively small-scale""' an be developed
without entire complement of agencies involved in negotiating and implementation process).
drftmagpin 21 City of Renton - DF-4FT
55-1779-07 October 14, 1993
OCT-15-93 FRI 14:41 PARAMETRIX FAX NO. 206 889 8808 P, 03/05
Much of the existing wetland on the mitigation sites is of low quality (e.g., young, alder with
poorly developed understory, no surface expression of hydrology, encroached on by dense
blackberry thickets). Mitigation construction could include enhancement of existing wetlands to
improve overall character and quality of system.
5.3.3.1 Opportunities in Mitigation Site 1
Mitigation Site 1 is adjacent to large, high value wetlarids (Category 1 wetlands based on the
City's rating system) which will not be filled or altered in the future. This provides the
opportunity to protect created wetlands on Mitigation Site I and the possibility of increased
functional values (i.e., providing connections between wetland systems owned by the City for the
purpose of providing habitat corridors and open space for passive uses) within and between the
neighboringwetland systems.
Mitigation Site 1 provides an opportunity to increase the acreage capacity of flood storage. This
site may provide storage opportunities for localized runoff from adjacent and upstream
developments as well as backwater storage from Springbrook Creek. A recent proposal by ��.�u
to re-align Springbrook Creek would route normal flows from SW 43rd Street north past and
along the west side of Site 1, then flow east toward Springbrook Creek. It would also route high
flows along the existing Springbrook Creek channel betwe-:n SW 43rd Street and SW 27th Street.
Incorporating a design feature that would route the water through Mitigation Site 1 before
flowing east to Springbrook Creek would positively impact Site 1 by providing greater hydrologic
support for the entire wetland system as well as provide the hydrology necessary to support
hydrophytic vegetation reestablished in the upland areas of the mitigation site.
Mitigation Site 1 provides an excellent opportunity for greatly enhancing the wildlife habitat, both
aquatic and terrestrial, at this site because of its size and greater isolation from urban
development.
The City of Renton recreation plans ( show trails in close proximity to Mitigation Site
1. These trails would provide opportunities for both passive recreation and education. Passive
recreation would include bird watching, walking, bicycling?, and photography. Education could
focus on wildlife, wetlands, salmonid biology, urban stormwater quality, etc., and could be
offered by interpretive signage and printed materials.
5.3.3.2 Opportunities in Mitigation Site 2
Mitigation Site 2 is adjacent to a historic natural riparian feature that has since been ehannelized.
The mitigation site's proximity to Springbrook Creek offers an opportunity to provide wildlife
linkages to other wetlands and open space areas as well as downstream benefits to fish and
wildlife,
Mitigation Site 2 offers an excellent and direct opportunit`7 to increase flood storage
drftm0g pin 22 City of Renton -DRAFT
S5-1779-07 October 14, 1993
OCT-15-93 FRI 14:42 PARAMETRIX FAX N0, 206 889 8808 P, 04/05
capacity because of its proximity to Springbrook Creek. The recent proposal mentioned above
would not appear to significantly affect opportunities to also re-align a portion of Springbrook
Creek through Mitigation Site 2. Diversion of high flows into this mitigation site would provide
increased water quality improvement for downstream receiving waters and detrital input to benefit
neighboring and downstream aquatic organisms. An Excellent opportunity exists for greatly
to Springbrook Creek,enhancing the wildlife habitat, both aquatic and terrestrial, at this site because of its proximity
The City of Renton recreation plans show trails along Mitigation Site 2. These trails
would provide opportunities for both passive recreation and education. Passive recreation would
include bird watching, walking, bicycling, and photography. Education could focus on wildlife,
wetlands, salmonid biology, urban stormwater quality, etc. and could be offered by interpretive
signage and printed materials.
An opportunity exists to keep some meadow areas relatively dry for small mammals as food
source for raptors, which use the area. However, this drier habitat could be wet meadow, thereby
meeting the goals for wetland creation. While there are still substantial areas of dry field/small
mammal habitat in the area, providing this type of habitat along with other types of habitat
increases the overall diversity and features inherent in a higher quality wetland system
5.3.4 Constraints
The City of Renton's wetland ordinance does not recognize enhancement as an acceptable form
of compensatory mitigation. There are approximately 25 acres of additional area that could be
enhanced and used for mitigation`,WkWg if the ordinance was modified in the future.
The available information on existing hydrology may not be adequate to develop site designs with
the level of specificity required to prepare a bid package. No groundwater monitoring has been
done on either site to establish seasonal fluctuations which would aid in the design of created
wetlands. Ideally, the level of ground water should be measured on both sites for at least 1 year.
Ground water wells constricted of PVC pipe could be installed and monitored over the winter
and spring, This additional information would allow the site designs to be modified to reflect
the changes in groundwater hydrology on both sites. Information on the level of groundwater
relative to the levels in Springbrook Creek have been eva:uated.
Perhaps the most challenging current constrain is the depth to ground water and the available
hydrology to reestablish wetlands on the mitigation sites. There is little available on-site water
to support created wetlands. Wetlands on both sites appear to have developed as a result of
surface water accumulation in slight depressional areas where, over time, finer sediments have
accumulated and reduced soil permeability. Hydrologic support for Mitigation Site 1 appears to
be from local precipitation, and possibly from a drainage ditch that extends along the western and
northerly property boundaries, Consequently, wetland hydrologic support is limited mostly to
precipitation. Hydrologic support for Mitigation Site 2 appears to also be from local precipitation
drftmag pin 23 City of Renton - DRAFT
55-1779-07 October 14, 1993
OCT-15-93 FRI 14:43 PARAMETRIX FAX NO. 206 889 8808 P, 05/05
a r
and Springbrook Creep, that extends along the easterly and southerly property bounda
ry, during
extreme storm and flooding events. Wetlands on both sates appear to have developed a perched
water table that is not hydrologically related to groundwater. Consequently, current wetland
hydrologic support is limited to local precipitation.
There is a potential that the diking district may place restrictions on reconstructing dikes or
removing a portion of the dike adjacent to Mitigation Site 2. The possibility of removing or
altering a portion of the dike will need to be discussed with the diking district to develop the site
plan for Mitigation Site 2.
Because of the depth to groundwater observed on the sites in July 1993, and the fact that filling
of both sites has placed ground elevations well above the original floodplain elevations, the costs
to excavate and remove soils will be high. In addition, these conditions will make it difficult to
establish a hydrologic connection between created wetlands on Mitigation Site 2 and Springbrook
Creek. Thus, a balanced cut and fill scenario is unlikely given the depth to which excavation
must occur if created wetlands are to utilize groundwater hydrology. Export of significant
amounts of material is likely. Although the costs for excavation will be relatively high, once
hydrology is obtained, wetland creation success probability increases with correspondingly lower
landscape costs (i.e., plant material costs).
Urban development is in close proximity to both sites. Springbrook Creek, adjacent to Mitigation
Site 2, is an engineered ditch and becomes isolated from other wetland and open space areas with
development of adjacent property to the north. Site 1 is relatively more isolated from urban
development, and is unlikely to have a major thoroughfare along one of its boundaries (once
construction of the gravity sewer system is complete). Nevertheless, this site has adjacent
commercial development along its southern boundary, and further development in this area is
likely to occur.
The soil seed bank on both sites probably does not contain some of the important plant species
(e.g., rushes, sedges, bulrushes, bur-reed, cattail, water parsley, water lily, etc) which might be
used in the mitigationg wetlands. Existing plant communities express what is held in the
seed bank (i.e., black cottonwood, red alder, salmonbeny, reed canarygrass, and Himalayan
blackberry).
Little wetland soils (e.g., peats or muck) are available on the sites for use in construction of new
wetlands. An appropriate planting medium and topsoil may need to be imported to the sites.
This raises an issue about the balance between costs and benefits of creating wetlands on the
upland portions of the mitigation sites. At what economic level does it become infeasible to do
this type of development and implementation and how is that balanced with the intrinsic issues
like habitat value? Ultimately, there must be an economic incentive to proceed -- it is governed
by markets, which operate even in the environmental arena.k„ `h1101111
'°'''��
drftmtigpin 24 City of Renton -DRAFT
55-1779-07 October 14, 1993
THE CITY OF RENTON
DEPARTMENT OF
PLANNING/BUILDING/PUBLIC WORKS `
FOURTH FLOOR
200 MILL AVENUE SOUTH
RENTON, WASHINGTON 9805 5-2 1 89 `
FAX: 235-2541
l
FAX TRANSMITTAL
DATE: /0//,3
T
TO: TI�IGFy FAX#: Zoo- 695- 9908
FROM: 57C61 (.Joao" PHONE#: �, �Sy�
SUBJECT: Cer' .(,sra'w olt 5-7-^Gj D,H-,✓a r/t Ica•-y ��.✓fy (� 1G 03�
W N(PAI " I. p/A7-y^ -0""" af CAS ON S'Tl c C/r G wf c t_
ASSu^,io />.E1TUr. V $,oG s
Number of pages excluding cover sheet:
CC, g il-L o 7 a
I I/funn>/m uc/Pn X CO V Flt.I X)C/Ith
PLANNING/ BUILDING/ PUBLIC WORKS DEPARTMENT ��`SY O�
MUNICIPAL BUILDING 200 MILL AVE. SO. RENTON, WASH. 98055
0 UTILITY SYSTEMS DIVISION - 235-2631 `�l Q�
NT
0 TRANSPORTATION SYSTEMS DIVISION - 235-2620
TO: DATE: JOB NO.:
RE:
ATTN:
GENTLEMEN:
WE ARE SENDING YOU ❑ ATTACHED ❑ UNDER SEPARATE COVER VIA THE FOLLOWING ITEMS:
❑ SHOP DRAWINGS ❑ PRINTS ❑ REPRODUCIBLE PLANS ❑ SPECIFICATIONS
o COPY OF LETTER o
COPIES DATE NUMBER DESCRIPTION AND REMARKS
THESE ARE TRANSMITTED AS CHECKED BELOW:
o FOR APPROVAL ❑ APPROVED AS SUBMITTED ❑ RESUBMIT COPIES FOR APPROVAL
❑ FOR YOUR USE ❑ APPROVED AS NOTED o SUBMIT COPIES FOR DISTRIBUTION
❑ AS REQUESTED ❑ RETURNED FOR CORRECTIONS o RETURN CORRECTED PRINTS
❑ FOR REVIEW AND COMMENT o o PRINTS RETURNED AFTER LOAN TO US
COPIES TO:
SIGNED
TITLE
IF ENCLOSURES ARE NOT AS NOTED, KINDLY NOTIFY US AT ONCE
C- 1iC J o 7 r 7-
CITY OF RENTON
Pam ,
MEMORANDUM
DATE: September 21, 1993 TIAc4i4 oM y/ Liw4w f
COMPANY /53
TO: Mary Lynne Myer PHONE x
FROM: Scott Woodbury / ��- 89-grt?u$ FAX
SUBJECT: WETLAND MITIGATION BANK PLAN
OUTLINE FOR PHONE CALL TO TOM MUELLER OF COE
REGARDING ADJACENCY DETERMINATION
On September 14, 1993 Corps of Engineers (COE) staff, Gail Terzi and T.J. Stetts, made
a site visit to the wetland mitigation bank sites for the purpose of completing the field
portion of the COE jurisdiction and wetland adjacency determination. Gail and T.J.
indicated that they would recommend to the COE technical committee that the wetlands
on bank site one be ruled adjacent and asked if the City would have any objections. The
wetlands on bank site two would also be considered adjacent unless the wetlands were
issued nationwide status as part of an earlier application. Because I lack the experience
that COE staff have concerning COE regulations and wetland science, I do not feel that I
am in a position to dispute their determination without the consultation of other City staff
and our consultants. Because of your experience our consultants recommended that you
contact the COE District Chief of Regulatory, Tom Mueller, to urge an nationwide
determination. It is important that the City contact COE prior to formal issuance of their
determination to request that the bank site wetlands be given nationwide status and not be
determined adjacent.
It is unlikely that an adjacency determination for our bank sites will jeopardize our project,
given the increasing COE support for such projects. However, it may set an undesirable
precedent for other wetlands in the valley. Adjacency determinations increase the COE
jurisdictional requirements which result in longer and uncertain the permit processes. This
is contrary to the City administration's support for streamlining the development process
and encouraging responsible economic growth. It is also possible that the objective of
establishing contiguous, higher quality wetlands in place of isolated, low quality wetlands
would not realized because adjacency determinations may limit the number of qualifying
donor sites which could afford to use the bank. It is therefore in the interest of the City
and the project to obtain a nationwide determination. As you had requested please find
following a summary of the important points for your conversation with Tom Mueller.
A. Official Regulatory Guidance for Adjacency Determinations not Established.
Tracey McKenzie of Parametrix told me that she attended an August 5, 1993 meeting of
the Wetland Committee of the Pacific Northwest Waterways Association. Mike Davis of
the COE Office of Regulatory Affairs presented a review and update of the workings of an
interagency committee of nine agencies on wetlands issues. The adjacency issue was
noted to be a mid-term issue of the committee and formal written guidance from
September 21, 1993
Page 2
headquarters to district offices would be provided within six months. If formal guidance is
not yet available, then on what basis will the COE make its determination of the bank
sites. At the site visit T.J. Stetts was asked for a copy of the adjacency determination
guidance and he acknowledged there was no formal guidance that could be given to the
City. The determination would be based on in-house guidance.
If COE cannot provide copies of the guidance on which the determination will be based, it
is impossible for the City to verify the determination or form and support an opinion on
what the determination should be. Similarly if a COE determination were challenged the
COE would have no defensible grounds of support. Official written guidance would
provide mutual benefits to all parties. If a determination of adjacency is to be made the
City requests the opportunity to meet with COE prior to issuance of the formal
determination. We_shou,d.also ask.the COE to define for us how the determination for
these two sites will set a precedence for future development projects.
B. Hydraulic Connection to Springbrook Creek not Evident. The wetland bank sites
neighbor the creek or other wetlands that are contiguous to the creek. While this
apparently may meet the definition of adjacent it is believed the subject wetlands must
also be hydraulically connected. The following reasons support the fact that there is no
evidence of a hydraulic connection to the creek.
1. Elevation Difference. The topography of both sites is sufficiently higher than the
surrounding drainage systems. The ditch along the west and north of wetland
mitigation bank site one is several feet lower and there is no physical evidence that
the site receives water from the ditch. The ditch apparently also does not convey
high flows given the amount of debris on its bottom. FEMA maps indicate that a
portion of wetland mitigation bank site one may be subject to flooding from the
100-year storm. However, evidence of flooding due to high Springbrook Creek
water levels at a frequency that would support wetland communities is lacking.
The topography of wetland bank site two is well above neighboring Springbrook
Creek. The site is not mapped by FEMA as being in the 100-year or 500-year
flood plain and there is no physical evidence of overtopping.
2. Recommended Source of Hydrology. In the site visit, COE staff recommended
that ideally the sites be excavated to a level that would allow utilization of
Springbrook Creek to provide wetland hydrology. This implies that there is no
hydraulic connection at present, but that it has to be established.
C. COE Previous Actions/Determination. The COE has previously issued nationwide
permits for projects in the valley with no determination of adjacency. This determination
would be inconsistent with past permit decisions issued by the COE which could result in a
legal dispute.
Please feel free to add any other information. If you have questions or comments please
call me at X-5547. I look forward to hearing how the call was received by the COE.
cc: Ron Straka
PLANNING/ BUILDING/ PUBLIC WORKS DEPARTMENT
MUNICIPAL BUILDING 200 MILL AVE. SO. RENTON, WASH. 98055 v !f y
D UTILITY SYSTEMS DIVISION - 235-2631 � ' 0�
NT
0 TRANSPORTATION SYSTEMS DIVISION - 235-2620
TO: DATE: JOB NO.:
RE:
ATTN:
GENTLEMEN:
WE ARE SENDING YOU ❑ ATTACHED o UNDER SEPARATE COVER VIA THE FOLLOWING ITEMS:
❑ SHOP DRAWINGS o PRINTS ❑ REPRODUCIBLE PLANS o SPECIFICATIONS
o COPY OF LETTER ❑
COPIES DATE NUMBER DESCRIPTION AND REMARKS
THESE ARE TRANSMITTED AS CHECKED BELOW:
❑ FOR APPROVAL ❑ APPROVED AS SUBMITTED o RESUBMIT COPIES FOR APPROVAL
❑ FOR YOUR USE o APPROVED AS NOTED ❑ SUBMIT COPIES FOR DISTRIBUTION
❑ AS REQUESTED ❑ RETURNED FOR CORRECTIONS ❑ RETURN CORRECTED PRINTS
o FOR REVIEW AND COMMENT ❑ ❑ PRINTS RETURNED AFTER LOAN TO US
COPIES TO:
SIGNED
TITLE
IF ENCLOSURES ARE NOT AS NOTED, KINDLY NOTIFY US AT ONCE
AU(i- J-U�s nUN 1 1 :Cb VANAML l K 1 X h AX NU. LUb bby bbUd r. U 1/U3
Parametrix, Inc.
5808 Lake Washington Blvd. N.E. Kirkland, WA 98033
206-822-8880
E�&Ejy
FAX TRANSMISSION COVER PAGE
FAX # 206-889-8808 AUu 9 , 1993
CITY OF RENTON
To: "-
Engineering Dept.
0
Fax#:
From:
IA ..ifi----------------------
------------
Date-
Number of Pages (Total): ...�5.....................-........................
Comments:
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DR.AFF
�32
Ms. Gail Terzi 3
US Army Corps of Engineers
PO Box 3755
Seattle, Washington 98124-2255
Dear Gail: 6 r- ,ter i9
TH/s LFil11f2 r TO Noun JiAA /ff3 r54Jpn WJ C.NVyt1rWp v/rp 7(LA6$y
July , 1993 tale.. ersaii R4ht+4he US Army T Twi
Corps of Engineers (Corps) complete a jurisdictional determination on wetlands identified
within parcels 8W and 14 owned by the City of Renton (see attached map), Parametrix and
Talasea are assisting the City in developing a mitigation program that would involve
converting the existing uplands on these two parcels to wetland communities for the
purposes of establishing large contiguous wetlands within the Black River drainage area.
The wetlands within the parcels were delineated by David Evans and Associates in 1991 and
the delineation lines were verified by the Corps in 1991, -*-
The City of Renton requests that the Corps complete the jurisdictional determination
regarding the adjacency status of the wetlands within the parcels for the following reasons:
• The results of the jurisdictional determination will assist the City as they move
forward with developing a comprehensive mitigation program that may include
mitigation banking for some wetland impacts within the Black River drainage basin
• The results will be used by the project team and the City to develop site specific
plans to convert the existing uplands on the parcels to wetlands. G,,/ �ot�.,+la�Y 4rk7rt--
w f 4 1"J1
'�-yNJU
In addition, the City and they
io}et team request written guidance on the type and extent
of permitting and regulatory requirements associated with converting the uplands to
wetlands on these parcels (i.e., the difference requirements associated with a 404 permit
versus nationwide permits).
Please contact n,at (206) 822=$8$Q-as soon as you have determined a date and time that
you and other Corps staff can conduct a site visit to the two parcels so that City of Renton
staffcacb�n f ui; -f",�Y tG...h,
and� e arrangements to meet you on-site. It is imperative that the--GUy elG
receive a written jurisdictional determination as soon as possible so that the project,team
can move forward with developing the programmatic and technical components of the
mitigation program. i
>ri
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Thank you for your assistance and coordination on this request. Please call A<if you need
additional information or have any questions.
Sincerely,
AvftLlo , J. sa/VACAr P.F,
S„Ale-^6c w,&eTE/- V'T 10-r k �
cc: Scott Woodbury
Mary Lynn Meyer
7/1 Llr�