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HomeMy WebLinkAboutSWP272171(29) Wetland Mitigation Bank Issue Paper Wetland Enhancement 1/20/94 Wetland Enhancement vs. Creation and Restoration Currently, the City's Wetland Ordinance does not recognize enhancement as an acceptable form of compensatory mitigation for impacts to wetlands. Acceptable compensation includes wetland creation, which is the creation of a new wetland in a location where none previously existed, or wetland restoration, which is the re- establishment of an historic wetland that no longer exhibits wetland functions due to activities such as filling or draining. The latter of these approaches is generally thought to be more likely to succeed. Though definitions vary slightly, the Washington Department of Ecology in their model ordinance defines enhancement as "actions performed to improve the condition of existing degraded wetlands so that the functions they provide are of a higher quality." The Environmental Law Institute similarly defines it as, "altering an existing wetland to add, or increase, particular wetland values and functions to levels not present under previous natural conditions, or to slow the natural impairment of existing values and functions." In the process of writing the City's Wetland Ordinance, enhancement was considered as type of compensatory mitigation but was ultimately not included in the Ordinance. The reasons for this are not entirely clear, but apparently City staff felt that it would be too difficult to determine whether or not an enhancement effort had successfully replaced the functions lost from the impacted wetland. This is a legitimate concern, since it is difficult to accurately and consistently measure wetland functions in the first place, and therefore would be difficult to objectively measure the increase in value from an enhancement project. It was also felt that allowing enhancement would result in a net loss of wetland acreage. The use of wetland enhancement requires some method of wetland functional valuation to determine adequate function replacement requirements. Wetland functions can be measured by using semi-quantitative assessment techniques such as the Wetland Evaluation Technique (WET) or the Habitat Evaluation Procedure (HEP), but results from these methods can vary with the specific functions, values and wetland types to be assessed. WET and HEP produce a quantitative rating by evaluating a number of different characteristics of a wetland. Generally, these assessment techniques should supplement qualitative assessment performed by well qualified wetland specialists. All evaluation methods are ultimately subjective making it unrealistic to expect consistent assessments even of the same wetland. Under the City's current Ordinance, the amount of wetland compensation required is based on acreage and wetland category. For example, a project impacting one- half an acre of a Category III wetland must create or restore one acre of Category III wetland elsewhere. The category (I, II, III) and type (forested, scrub-shrub, emergent), as well as the area of a wetland impact are determined by a qualified wetland ecologist. The created/restored wetland is intended to replace these lost features. If allowed, enhancement would likely be based on similar area replacement ratios. Still, some method of determining the increase in function would be needed. Do Other Jurisdictions Allow Enhancement? Department of Ecology Model Ordinance The Department of Ecology's Model Ordinance discusses enhancement stipulating that applicants proposing enhancement shall identify how enhancement conforms to the overall goals and requirements of a city's ordinance and established regional goals. An enhancement project is deemed acceptable as long as enhancement for one function or value will not degrade another function or value and that acreage replacement ratios shall be doubled to recognize existing functional values. Also, category I wetlands cannot be enhanced. Kirkland Kirkland's wetland mitigation requirements are explained in a memorandum titled "Wetland Impact Analysis Guidelines." Mitigation plan guidelines are quite general and do not exclude enhancement as a form of compensation. In all cases, the project proponent must submit a mitigation plan to the city's wetland consultant for review. Apparently, Kirkland has a very flexible approach relying heavily upon the judgment of it's wetland consultant to determine whether or not a wetland enhancement plan adequately replaces the wetland functions and values to be lost. Redmond Redmond's Wetland Ordinance allows enhancement stipulating that enhanced wetlands shall have higher wetland values and functions than the altered wetland. It also requires that the values and functions transferred shall be of equal or greater quality to assure no net loss of wetland values and functions. Redmond's enhancement ratio for impacts to Type II and III wetlands is 1 :1, and for Type I wetlands is 2:1 . Tukwila Tukwila allows enhancement at a ratio of 1.5:1. Should Renton Allow Enhancement? Enhancing a wetland is technically feasible and usually results in improved functions and values. The difficulty with enhancement as a compensatory mitigation is in determining how much enhancement of a degraded wetland is needed to replace the functions and values lost at the impacted wetland. Most city staff are not qualified to make this judgment and the opinions of wetland ecologists will vary making it difficult to objectively and consistently evaluate enhancement efforts. While enhancement is possible, it is a mitigation approach that requires caution. Introducing new functions or stimulating particular functions over others could compromise the functions of an existing wetland. It is also difficult to know whether new or enhanced functions proposed for a wetland can be sustained and are ecologically sound. Enhancement would benefit the City's mitigation bank project because it would allow the City to alter and improve the low quality wetlands on the mitigation bank sites. This would increase the number of wetland credits the City could offer for sale from the bank sites and possibly decrease the cost of creating credits. On the other hand, enhancement could provide a less expensive alternative to wetland creation or restoration and may be more easily pursued on-site, thus reducing the potential users of the mitigation bank. Enhancement does not generally increase the volume of floodwater that can be stored in a wetland, and flooding is a significant concern in the lower portion of the Black River drainage basin. Also, at the expense of the increase in functional value, enhancement results in a net-loss of wetland acreage. Conclusion Many jurisdictions in the Puget Sound Region allow enhancement as a form of compensatory mitigation. However, the cities surveyed did not have extensive guidance on how enhancement should occur and be evaluated. Most stipulate that the enhancement should replace the functions lost from the wetland impacted and most required a wetland area greater than the impact to be enhanced. Allowing enhancement gives the City more flexibility in restoring wetlands on the mitigation bank sites, and probably will result in the creation of more "credits." However, allowing enhancement city-wide may also make on-site mitigation less expensive for a developer than using the City's mitigation bank, reducing the potential number of customers and thus, the return on the City's investment in the bank. One possible approach to allowing enhancement on the bank sites and not elsewhere could be the inclusion of a waiver in the Ordinance that would permit enhancement for special, comprehensive projects, such as the mitigation bank project, which are committed to and effective at increasing the City's wetland functions and values (see 4-32-5.D in the Ordinance). P,,eP, Bx $a 6 AI.7 tik F'-.2 o-�Fzfwk Sys s Di✓. t� P b I flax s� velep�ble- TA zt Ad,v-ea Avem P !$ � ?2.92- 23 o i3.,G( So _ -76 --- - ---- - ----_ ?2, _- o -- 'o+a.1 134S, 3s - -1 6_4 . 9 2 1 i DEN2010.XLS f / ttt BBG` PYe,O.By : Alan �GHNS�h� Z+a9 RURALURBANUNUSED TOTAL POP./ POP./ JOBS/ POP+JOBI TOTAL TOTAL TOTAL TAZ ACRES ACRES ACRES ACRES TAZ RURAL URBAN URBAN URBAN TAZ RURAL URBAN JOBS W _A=$ ACRE ACRE ACRE ACRE POP POP 40 0.00 137.96 43.11 181.07 40 0.00 11.45 0.20 11.66 40 0.00 1580.17 27.98 41 20.94 40.15 61.92 123.01 41 0.43 8.75 8.42 17.17 41 9.00 351.29 338.00 42 46.81 254.51 156.00 457.31 42 0.43 6.36 4.24 10.60 42 20.13 1619.12 1078.43 43 0.00 93.30 38.56 131.86 43 0.00 8.74 7.34 16.08 43 0.00 815.40 685.24 44 0.00 138.64 1.18 139.82 44 0.00 0.00 0.00 0.00 44 0.00 0.0 5 0.00 45 16.75 25.39 13.02 55.15 45 0.43 12.17 0.47 12.64 45 7.20 308.8 12.00 46 10.33 61.98 21.48 93.79 46 0.38 7.37 0.16 7.53 46 3.88 456.95 10.00 47 0.00 110.38 22.75 133.14 47 0.00 13.25 0.08 13.33 47 0.00 1462.59 9.00 48 75.74 117.57 105.59 298.90 48 0.38 8.04 1.62 9.66 48 28.48 945.14 191.00 49 43.43 12.71 37.49 93.63 49 0.38 47.68 0.00 47.68 49 16.33 605.98 0.00 50 25.51 16.53 33.00 75.04 50 0.56 4.63 1.03 5.66 50 14.39 76.57 17.00 51 50.63 117.51 97.32 265.47 51 0.56 18.73 0.47 19.20 51 28.56 2200.65 55.59 52 0.00 44.48 63.06 107.54 52 0.00 6.21 0.22 6.44 52 0.00 276.36 10.00 53 0.00 96.21 14.28 110.49 53 0.00 22.65 1.87 24.53 53 0.00 2179.56 180.00 54 0.00 14.80 1.90 16.70 54 0.00 5.88 0.00 5.88 54 0.00 87.04 0.00 55 0.00 0.00 0.00 0.00 55 0.00 0.00 0.00 0.00 55 0.00 0.00 0.00 56 0.00 0.00 0.00 0.00 56 0.00 0.00 0.00 0.00 56 0.00 0.00 0.00 57 15.64 37.47 40.40 93.50 57 0.44 7.39 1.60 9.00 57 6.91 277.05 .00 58 58 0.00 47.82 17.76 65.58 58 0.00 7.71 1.21 8.92 58 0.00 368.53 58.00 59 0.00 65.18 45.09 110.27 59 0.00 2.45 2.75 5.20 69 0.00 159.86 179.00 60 0.00 60.46 5.54 66.00 60 0.00 14.11 0.24 14.35 60 0.00 853.06 14.60 61 0.00 69.32 32.40 101.72 61 0.00 7.24 0.27 7.51 61 0.00 501.67 19.00 62 0.00 0.00 0.03 0.03 62 0.00 . 0.00 0.00 0.00 62 0.00 0.00 0.00 63 0.00 5.50 9.68 15.18 63 0.00 16.39 0.18 16.57 63 0.00 90.22 1.00 64 0.00 0.00 0.79 0.79 64 0.00 0.00 0.00 0.00 64 0.00 0.00 0.00 65 0.00 0.40 0.97 1.37 65 0.00 t4. 0.00 0.00 65 0.00 0.00 0.00 66 0.00 97.24 46.61 143.85 66 0.00 0.93 8.73 66 0.00 758.03 90.58 67 6.49 20.53 27.78 54.79 67 0.44 0.15 9.72 67 2.87 196.52 3.00 68 0.00 60.99 38.86 99.85 68 0.00 32.15 36.61 68 0.00 271.59 1961.00 69 0.00 0.15 1.73 1.89 69 0.00 0.00 0.00 69 0.00 0.00 0.00 70 0.00 0.00 1.48 1.48 70 0.00 0.00 0.00 0.00 70 0.00 0.00 0.00 71 54.18 99.36 137.41 290.95 71 0.44 27.40 7.29 34.69 71 24.06 2722.06 724.65 72 0.00 82.09 34.80 116.88 72 0.00 0.24 9.80 10.04 72 0.00 19.32 804.83 73 16.94 64.41 21.27 102.61 73 0.00 0.00 17.49 17.49 73 0.00 0.00 1126.33 74 0.00 49.93 35.54 85.47 74 0.00 7.41 15.47 22.88 74 0.00 369.84 772.29 75 0,00 76.33 29.55 105.88 75 0.00 0.00 18.92 18.92 75 0.00 0.00 1443.94 S 76 68.02 26.05 24.72 118.79 76 0.00 0.00 24.80 24.80 76 0.00 0.00 645.92 77 63.33 56.18 0.08 119.59 77 0.00 0.00 4.00 4.00 77 0.00 0.00 225,00 78 0.00 151.17 1.83 153.01 78 0.00 0.00 72.76 72.76 76 0.00 0.00 11000.00 79 0.00 95.08 44.31 139.39 79 0.00 0.09 30.89 30.98 79 0.00 8.28 2937.02 80 0.00 4676 47.51 94.27 80 0.00 0.24 10.52 10.75 80 0.00 11.04 491.81 el 0.00 73.25 17.221 90.471 811 0.00 0.41 15.04 15.45 81 0.00 30.36 1101.78 ` (( Pulof,c ��G(cYc�.f tG�af ka�e eN•�(oy..e..fi Row., Seas(ftuc +4<-ea.5 Page 2 DEN2010.XLS RURAL URBAN UNUSED TOTAL POP./ POP./ JOBS/ POP+JOB/ TOTAL TOTAL TOTAL FA ACRES ACRES ACRES ACRES TAZ RURAL URBAN URBAN URBAN TAZ RURAL URBAN JOBS ACRE ACRE ACRE ACRE POP POP 0.00 0.00 0.00 0.00 166 0.00 0.00 0.00 0.00 166 0.00 0.00 0.00 0.00 0.00 0.00 0.00 167 0.00 0.00 0.00 0.00 167 0.00 0.00 0.00 0.00 0.00 0.00 0.00 168 0.00 0.00 0.00 0.00 168 0.00 0.00 0.00 0.00 0.00 1.81 1.81 169 0.00 0.000.00 0.00 169 0.00 0.00 0.00 0.00 0.00 0.00 0.00 170 0.00 0.000.00 0.00 170 0.00 0.00 0.00 0.00 0.00 0.00 0.00 171 0.00 0.00 0.00 0.00 171 0.00 0.000.00 0.00 1.46 0.47 1.93 172 0.00 0.00 0.00 0.00 172 0.00 0.00 0.00 173 0.00 15.91 13.86 29.77 173 0.00 0.00 55.05 55.05 173 0.00 0.00 875.80 174 0.00 24.13 3.34 27.47 174 0.00 0.00 36.27 36.27 174 0.00 0.00 875.00 175 0.00 31.52 4.70 36.22 175 0.00 0.00 24.59 24.59 175 0.00 0.00 775.00 176 0.00 47.67 14.34 62.01 176 0.00 0.00 10.39 10.39 176 0.00 0.00 495.14 177 0.00 16.19 18.22 34.41 177 0.00 1.35 26.87 28.21 177 0.00 21.84 435.00 178 0.00 26.37 29.39 55.76 178 0.00 0.00 12.04 12.04 178 0.00 0.00 317.44 179 0.00 44.37 4.16 48.53 179 0.00 0.00 39.55 39.55 179 0.00 0.00 1755.00 180 0.00 28.18 10.62 38.80 180 0.00 0.00 39.29 39.29 180 0.00 0.00 1107.00 181 0.00 17.26 13.37 30.63 181 0.00 0.64 0.00 0.64 181 0.00 11.04 0.00 `C 182 0.00 1.29 0.66 1.95 182 0.00 0.00 0.00 0.00 182 0.00 0.00 0.00 1831 0.00 0.00 0.00 0.00 183 0.00 0.00 0.00 0.00 183 0.00 0.00 0.00 184 0.00 0.00 0.00 0.00 184 0.00 0.00 0.00 0.00 184 0.00 0.00 0.00 657.651 6302.851 3367.431 10327.921 1 212.77 53895.10 81105.10 gcx4K Va ( 14 Tof l _ �naszb�e r t N MA ? 74 S5.+7S.s4 4q. 9 3 5 77 11q.59 ms, 99 ;9.ss 76.33 ?90 # 08 /g .Sl ►, 83 /St.11 95,08 13 4. 2� ¢.St• 19, 39 24,3? 4%.e3 q,IL 44,37 ISO 3a.ae ic,b2 1, 7,11 z To4a( 1300.09, 315.37 g�g9 Pape 5 JL_J t 3 ;, J o5Q -Ji Ull IS)!YJ 101 N1 'Vy4 (7:7' K tom_ L7 =•��F'I t -__f It )yil _ -•.1�nh- _. � 1 - -. _ _ ._ � '�f�f�.�:1 Av Gfl' • � Yw � I I _ I� S _-_MS IgS7tlTf_ AS AV IYA �, � Interested Agencies fNOMOVA s James Schafer 705-7Y„3 Bob Lyon Wash State Dept of Transportation Soos Creek Water/Sewer P O Box 47329 P O Box 58039 Olympia WA 98504-7329 Renton WA 98058-1039 Jonathan Fordge Heather Stout 7 9(,- e z i 3 R. O. Aye Metro King County Surface Water Mgmt Wash State Dept of Transportation 821 Second Avenue MS 81 111 Third Avenue STE 1100 P O Box 330310 Seattle WA 98104 Seattle WA 98101 Seattle WA 98133-9710 Bill Wolinski Dennis Dowdy Ross Ernst City of Kent Public Works Tim Carlaw Phil Fraser 220 Fourth Avenue South City of Auburn Public Works City of Tukwila Public Works Kent WA 98032-5895 25 West Main 6200 Southcenter Bldg Auburn WA 98001-4998 Tukwila WA 98188 John E. Nelson .)P(-k/I 1416Nlow"o- King County Drainage District#1 Z /VI WR.Sonu , sT)F tug 601 West Gowe SE r�E� WO, r�g1o9 Kent WA 98032 H:DOCS:Agency2:SSW:ps Wetland Mitigation Bank Project Attendees of 10/21/93 Public Meeting: Tim Puryear Jim Douma H. Seelig 700 5th Avenue - STE 7600 521 Wall Street P 0 Box 1925 Seattle, WA 98104 Seattle WA 98121 Bellevue WA 98009 223-6292 448-4699 454-0885 Janet Garrow Rhys Sterling Paul B. Crane 701 - 5th Avenue - STE 7000 800 Bellevue Way NE-#376 The Boeing Company Seattle WA 98104 Bellevue WA 98004 P O Box 3707 - MS 6;=44 587-0700 454-8272 Seattle WA 98124 965-1170 J l-S•ai,I (W � 1anr� c v* �tSu 3 H:DOCS:93-1035a:SSW:ps Wetland Mitigation Bank Project Attendees of 10/20/93 Public Meeting: Colleen Cole-Bowron Martha Parker Laurinda Johnsen 601 Cedar Avenue South 18028 - 187th Ave SE P. O. Box 161 Renton WA 98055 Renton WA 98058 Renton WA 98057 432-5498 Ray E. Fournier Kent Lind T. Steger 4700 Talbot Road South 6027 - 28th Avenue NE 6209 - 30th Avenue NE Renton WA 98055 Seattle WA 98115 Seattle WA 98115 526-0789 528-6019 Sally L. Steiner Richard Chase 17818 - 109th Avenue SE City of Kent Renton WA 98055 220 -4th Avenue South 228-0124 Kent WA 98032-5895 859-3950 H:DOCS:93-1033a:SSW:ps To Do 1 . setup date for second agency meeting 2. contract for surveying and wetland monitoring wells 3. Products agenda bills committee reports request for legal approval request for risk management approval issue paper budget adjustment ordinance sepa checklist storm drainage report project narrative shoreline justification neighborhood detail map site plan grading plan landclearing/tree cutting plan landscape plan variance justification conditional use permit justification site plan approval justification fill and grade justification notice of shoreline permit notice of sepa determination shoreline permit decision hydraulic project approval application 404 permit application short term water quality modification permit erc determination erc staff report hearing examiners staff report preliminary design drawings bid documents (special provisions) license from drainage district no. 1 predesign report final design report fill disposal site permits (boeing/others) sale agreement for fill preconstruction vegetation management permit right-of-entry alternative analysis report meeting minutes and agenda ('lc �,- i `-�� ti CITY OF RENTON Ly E I V D b MEMORANDUMY . , �? u DATE: April 28, 1992 TO: Larry FROM: Lynn Guttmann i STAFF CONTACT: Mary Lynne Myer SUBJECT: Purchase of Glacier Park Property from Surface Water and Transportation Funds We are considering expenditure of transportation and surface water utility funds in the amount of$310,000 for the purchase of Parcel 1, wetlands, in the Glacier Park Auction Group. There are two justifications for the purchase of this property: Stormwater flood control and water quality, and transportation benefits. However, we have several questions which need answers before we can proceed with the transaction. SURFACE WATER Surface Water Section will contribute $50,000 towards the purchase price of Parcel 1, 3, and 4. Parks will contribute the remaining $50,000 for a total of$100,000 purchase price. An additional $260,000-270,000 would be needed to remove the LID encumbrances on the property. This money would come from the Transportation Division. TRANSPORTATION Our justification for the $260,000-270,000 expenditure is the possible future benefit to the transportation system of the proposed 27th Street HOV lanes. The benefits to this project are based upon right of way needed for widening 27th, access rights needed for the facilitation of the operation of the HOV lanes and wetland banking costs as required by the City's wetland ordinance and likely by the Corps of Engineers' regulations due to the amount of fill which may be required for widening. Transportation Division estimates the following fill requirements: Parcel 1 1000 ft long by 30 ft. width = 3000 sq ft. (.68 acre) The acknowledged value of the right of way which would be used for the widening is $180,000. (1000 ft long x 30 ft wide x approximately $4-6 a sq ft = $120,000- 180,000) This wetland is likely a Category 1, shrub-scrub wetland which must be replaced at a 3:1 ratio, according to our wetlands ordinance. (see attached description of the wetlands from the Black River Water Quality Wetlands Inventory, Jan 1992, Jones and Stokes, for the Stormwater Division.) In addition, mitigation will be needed for the filling of another .68 acre on the adjoining City of Renton wetlands, also necessary for widening of 27th Street. In total, 1.36 acres of wetland would be filled. At a 3:1 ratio, 4.08 acres of mitigation would be needed. Assuming that 4.08 acres of mitigation would cost $22,000-$25,000 an acre, total costs for mitigation would be $88,000- 90,000. The Transportation Division i n to cont' + $90,000 = 270, for this strip of land. e understanding must be that the Transportation Division as o way easement on this strip on Parcel 1 adjacent to 27th Street while Surface Water Utility would be the owner of the parcel itself. It also must be understood that the Transportation Division has "reserved" 4.08 acres in one of the newly acquired wetland mitigation bank parcel thus meeting the project's obligation to the City's wetland ordinance. QUESTIONS Is the wetland bank "reservation" concept legally feasible? Is it possible for Surface Water Division to issue a right of way easement for this strip of land to Transportation Division? If not, can Transportation Division refund Surface Water Utility for the purchase price of this strip of land and retain ownership? We would appreciate your response as soon as possible as time is short, as you know. cc: John Webley, Community Services Department Mel Wilson, Transportation Ron Straka, Utility Priscilla Pierce, Administration Lee Haro, Transportation Lee Wheeler, Fire Department attachment CITY OF RENTON MEMORAIINDUM DATE: April28, 1992 TO: Lynn Guttmann Mel Wilson FROM: Mary Lynne Myer SUBJECT: Wetland banking options for wetland parcel 1 Parcel 1 is not a low grade wetland by the definitions in the wetlands ordinance. The Storm Water's Wetland Inventory— Black River Water Quality Management Plan/ESGRW (p. 24) describes it as: Size : one of the largest wetlands in the study area. Covers entire area between 27th Street, Lind Avenue, Springbrook Creek and southern boundary of property. Elevation: the wetland is at original valley floor elevation and has not been filled. Ground water recharge: high values Infiltration and recharge: high values due to its lack of a surface water inlet which allows flood flows to remain in the wetland for exceeded lengths of time. Flood storage capability: very high values. Wetland is at original elevation and is considerably lower than surrounding fill area. Function is enhanced because of large size, dense vegetation, and location to fill. Shoreline anchoring: very high values. Dense vegetation line the banks adjacent to Springbrook reducing turbulence from overland flow during flood event. Water purification: very high values. Large size, dense stands of cattails, and long residence time of water contribute to this value. Food chain support: medium values due to lack of open water. Wildlife habitat: medium values due to lack of open water. Active passive recreation: high values. Memo to Lynn Guttmann and Mel Wilson April 28, 1992 Page 2 Although it has not been officially classified by a wetlands specialist, I would guess it is a Class 1 wetland, shrub-scrub vegetation class. Replacement ratios under the ordinance are 3:1. If portions of the wetland were filled for any reason, some other area would have to be excavated and established as a wetland for mitigation in order to keep with the ordinance's requirement for no net loss. Because this wetland does not contain any fill at all, another area would be needed for replacement. The ordinance does allow variances for projects which meet several public purpose tests. It appears that this project would meet 2 of 4 variance criteria for public projects. My major concern is how do we address the net loss of wetland area if fill is placed in the wetland. We have adequate area in the wetland mitigation bank but we do not have any money for a plan or for excavation. If a mitigation plan can be funded for the bank area, and if we can pay for excavation it would seem we have met the requirements of our own ordinance and we would also meet DOE and COE requirements.