Loading...
Planning Commission Packet - 12/01/1981 POOR QUALITY RECORD PLEASE NOTE: The original paper record has been archived and put on microfilm. The following document is a copy of the microfilm record converted back to digital. If you have questions please contact City of Tigard Records Department. MINUTES TIGARD PLANNING COMMISSION December 1, 1981. Fowler Junior High Lecture Room 10865 S.W. Walnut St. - Tigard President Tepedino called the meeting to order at 7:35. ROLL CALL: Present: Tepedino, Speaker, Moen, Kolleas, Herron, Helmer, Owens, Bonn, Christen arriving at 7:40 p.m. Staff: Associate Planner Newton; Diane Jelderks, Support Staff arriving at 7:40, Ed Sullivan, Attorney; Frank Currie, Planning Director. The minutes of the November 10 meeting were considered. Mr. Speaker corrected the spelling of two names, Mel Stout on page two and Mr. Nicholas on Page four. Mr. Speaker MOVED that the minutes be accepted with corrections made, seconded by Moen, approved with. corrections by unanimous vote. COMMUNICATION: Newton - informed Planning Commission that it was only necessary to elect new officers every two years. Elections required to be held the first month of every odd year. Brought up in discussion was the fact that Chairman Frank Tepedino, Commissioner Speaker and Commissioner Kolleas appointments expired 7-1-82. (Secretary's note: Commissioner Owens also expires 7-1-82.) Commissioner Bonn commented he favored Chairman Tedpedino remaining in his position until term expired. Tepedino said he had no problem with that. The President then opened the Study Session by turning the meeting over to Mr. Sullivan, Attorney for the City, for presentation of Administrative Procedures. Mr. Sullivan passed out two charts showing process for Planning Director decisions and appeals and decision-making processes by Approval Authorities other than Director. He also expressed his appreciation to the Planning Commissioners, especially Commissioner Speaker, for their input and two major changes in the procedures. Special attention was first brought to Section 18.84.050 Approval Authority, which included the position of a Hearings Officer. There was lenghty discussion regarding the need of a Hearings Officer, how one would be hired, who would do the hiring and what effect this would have on the Planning Commission. There was a change made in Section 18.84 050 b, item number 7: "Application for extension of time". This places the authority under Planning Director rather than Planning Commission. Mr. Sullivan then covered Administrative Procedure, section by section, answered questions raised by the Commissioners, clarified new procedures and made minor corrections. COMMISSION ACTION: Mr. Speaker made a MOTION that the Administrative Procedures, with admendments and correctionsf, be taken to the City Council with further discussion to be made regarding the Hearings Officer. The motion was seconded by Moen, carried unanimously. MINUTES TIGARD PLANNING COMMISSION December 1, 1981 Page 2 Further discussion was made as to how to have the concerns of the Planning Commission, regarding the Hearings Officer, made to the City Council and City Administrator. Tepedino MOVED that the following items be recommended to the City Council regarding the Hearings Officer issue: 1. Office to have a term of one year. (six month review) 2. Planning Commission to be able to review annually. 3. Have a 3 member committee for hiring including one Planning Commissioner. 4. Removal because of neglect or malfeasance 5. A determination of need to be made with the Planning Commission. 6. Planning Commission to be notified of all Hearings Officers decisions. Sullivan stated he would include these items in the Ordinance if motion passed. Speaker seconded the motion, carried unanimously. The President declared a five-minute recess. FLOODWAY ORDINANCE Frank Currie, Planning Director explained that staff would like for the Planning Commission to make a recommendation to City Council on a Floodway elevation for the sole purpose to allow the City to participate in the Flood Insurance Program. Currie, explained how the "0" foot Floodway and the "1" foot Floodway relates to the Flood Insurance and how it relates to what the City is doing with the floodplain. He gave examples of what would happen if there were a flood and how each of the above options would effect damaged buildings in the floodplain. He explained that the main purpose is to allow citizens of Tigard to obtain Flood Insurance and have the rates set. Discussion followed with Tepedino expressing much concern regarding the issue "If we passed a "0" foot Floodway would this then enable developers to develope within the 100 year floodplain." Currie explained that the City Code controlled what would be done in the floodplain and even though the "0" foot Floodway would be less 1 restrictive (as it relates to insurance rates) .and does not allow building in the flood- plain. This action is only necessary to be able to establish rates.for Insurance. J.B. Bishop commented that more lenders are automatically requesting Flood Insurance and the premium is quite high unless the City has passed a "0" or "1" foot Floodway. Tepedino requested having someone of authority from the Federal Emergency Management Agency speak to the Commission prior to making a decision. Staff said because of the time involved that would be impossible as the Floodway had to be accepted by February 1, 1982 to be eligible for this program. Moen MOVED to recommend to City Council for a "0" foot Floodway, seconded by Speaker and carried eight to one, with Tepedino voting no. • MINUTES TIGARD PLANNING COMMISSION December 1, 1981 Page 3 NOISE ORDINANCE Liz Newton presented wording for the City of Tigard Zoning Code relative to compliance with DEQ noise standards. This wording would be inserted into the Industrial Zone sections M2, M3 and M4, as follows: All uses in an (M3) (M4) (M2) zone shall comply with environmental standards as adopted by the State of Oregon Department of Environmental Quality for air, land, noise and water. If it is deemed necessary by the Planning Director or his agent, evidence of compliance with DEQ standards for air, land, noise or water may be required. Evidence shall be in the foam of a letter or copy of a permit' from the regulatory agency. Ms. Newton also had a letter from Maggie Conley of the Department of Environmental Quality approving wording as well as, a memo from Sullivan's v office approving wording. Speaker made a MOTION to recommend to City Council the above wording to be added to the appropriate sections of the Tigard Municipal Code, seconded by Helmer, carried unamiously. Liz Newton submitted several applications for NPO # ,3. Due to the fact they were incomplete and not clear whether Mr. or Mrs. was applying, she was requested to return them to the NPO members to be resubmitted at another time. f.. The President declared the meeting Adjourned at 11:50. MINUTES TIGARD PLANNING COMMISSION December 1, 1981 Page 2 Further discussion was made as to how to have the concerns of the Planning Commission, regarding the Hearings Officer, made to the City Council and City Administrator. Tepedino 'MOVED that the following items be recommended to the City Council regarding the Hearings Officer issue: 1. Office to have a term of one year. (six month review)t "" � "�"P' f 2. Planning Commission to be able to review annually.04 SG/1 L G 3. Have a 3 member committee for hiring including one Planning Commissioner. 4. Removal because of neglect or malfeasance 5. A determination of need to be made with the Planning Commission. 6. Planning Commission to be notified of all Hearings Officers decisions. Sullivan stated he would include these items in the Ordinance if motion passed. Speaker seconded the motion, carried unanimously. The President declared a five-minute recess. FLOODWAY ORDINANCE Frank Currie, Planning Director explained that staff would like for the Planning Commission to make a recommendation to City Council on a Floodway elevation for the sole purpose to allow the City to participate in the Flood Insurance Program. Currie, explained how the "0" foot Floodway and the "1" foot Floodway relates to the Flood Insurance and how it relates to what the City is doing with the floodplain. He gave examples of what would happen if there were a flood and how each of the above optionS'would effect damaged buildings in the floodplain. He explained that the main purpose is to allow citizens of Tigard to obtain Flood Insurance and have the rates set. Discussion followed with Tepedino expressing much concern regarding the issue, "If we passed a "0" foot Floodway would this then enable developers to develope within the 100 year floodplain." Currie explained that the City Code controlled what would be done in the floodplain and even though the "0" fdtot Floodway would be less restrictive (as''it relates.:toAnisurance. rates)?,and does not allow building .in. the flood- plain. This action ,is'; only necessary.,to be able to establish rates.for Insurance. J.B. Bishop commented that more lenders are automatically requesting Flood Insurance and the premium is quite high unless the City has passed a "O" or "1" foot Floodway. Tepedino requested having someone of authority from the Federal Emergency Management Agency speak to the Commission prior to making a decision. Staff said because of the time involved that would be impossible as the Floodway had '0 be t+Ai 0 MP accepted by February 1, 1982 to be eligible for this program. Moen MOVED to recommend to City Council for a "0" foot Floodwa Ys Speaker and carried eight to one, with Tepedino voting no. �� econded by 4o, l ! "a' } PLANNING COMMISSION ROLL CALL MEETING Date j Frank Tepedino Clifford Speaker Pi Don Moen Geraldine Kolleas Mark Christen f7;411() Susan Herron Richard Helmer ) Bonnie Owens Roy Bonn 411 le i 1 r .,,r5 -/_.... id ....ix..„,,.„. . INSURANCE _ 410„Ir S .1 V . ,, . ii S 9 - 'r 'SyA 1, a 7t >} � r@ � '. CITY OF TIGARD, • . OREGON WASHINGTON COUNTY • • • ft,j, „A Vt% SEPTEMBER 1, 1981 t' .: Federal Emergency Management Agency . i -44.'% '' o , COMMUNITY NUMBER•410276 ti TABLE OF CONTENTS Page 1.0 INTRODUCTION......'...... .....:... OOOOOO OO OO............. . 1 1.1 Purpose of Study.... ................. ........OOOOO.... ..... 1 1.2 Authority and Acknowledgments.. .. .. ......OOOO.............. 1 1.3 Coordination......'. ... .. .. .......... .. .. ......... .... . 1 2.0 AREA STUDIID............. . .. ..........,..... :...... .... •• 2 2.1 Scope of Study... .. ... ... 2 2.2 Community Description.. . . .. . 2 2.3 Principal Flood Problems... .... ................. .. 4 2.4 Flood Protection Measures.. .............. 6 3.0 ENGINEERING METHODS... ...... ..... . . . . 3.1 Hydrologic Analyses........, 6 3.2 Hydraulic Analyses... .. .... 7 4.0 FLOOD PLAIN MANAGEMENT APPLICATIONS, .. 9 4.1 Flood Boundaries..,.. .. 9 4.2 Floodways..... 10 5.0 INSURANCE APPLICATION.. 13 5.1 Reach Determinations 13 5.2 Flood Hazard Factors 14 5.3 Flood Insurance Zones 14 5.4 Flood Insurance Rate Map Description 16 6.0 OTHER STUDIES. ..... 16 7.0 LOCATION:OF DATA.. . 16 8.0 BIBLIOGRAPHY AND REFERENCES... ..................... 17 • i { c TABLE OF CONTENTS (font°d) Page FIGURES Figure 2 Estimated Flood Elevations...... ........... ............. ... . 5 Figure 3 Historic Flooding. .. ........ ......... .... .... .. .......... .. . 5 Figure 4 - Floodway Schematic.... . . 13 TABLES, Table 1 - Summary of Discharges......... . ........................... . 8' Table 2 - Floodway Data.... . ................... .................. 11 Table 3 - Flood Insurance Zone`Data.................................... . 15 EXHIBITS Exhibit 1 Flood Profiles Tualatin River Panel O1P Fanno Creek Panels 02P-04P ` Ash Creek Panel 05P Summer Creek Panels 06P-07P Exhibit 2 - Flood Boundary and Floodway Map Index Flood Boundary and Floodway Map PUBLISHED SEPARATELY: Flood Insurance Rate Map Index Flood Insurance Rate Map ii FLOOD INSURANCE STUDY 1.0 INTRODUCTION 1.1 Purpose of Study This Flood Insurance Study investigates the existence and severity of flood hazards in the City of Tigard, Washington County, Oregon, and aids in the administration of the National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973. This study will be used to convert Tigard to the regular program of flood insurance by the Federal Emergency Management Agency. Local and regional planners will use this study in their efforts to promote sound flood plain management. In some states or communities, flood plain management criteria or regulations may exist that are more restrictive or comprehensive than those on which these federally supported studies are based. These criteria take precedence over the minimum Federal criteria for purposes of regulating development in the flood plain, as set forth in the Code of Federal Regulations at 24 CFR, 1910.1(d) . In such cases, however, it shall be understood that the State (or other jurisdictional agency) shall be able to explain these requirements and criteria. 1.2 Authority and Acknowledgments The source of authority for this Flood Insurance. Study is the National Flood Insurance Act of 1968, as amended. The hydrologic and hydraulic analyses for this study were performed by the U.S. Army Corps of Engineers, Portland District, for the Federal Emergency Management Agency, under Inter-Agency Agreement Nos. IAA-H-7-76 and IAA-H-10-77, Project Order Nos. 17 and 1, respectively. This work, which was completed in June 1980, covered all significant flooding sources affecting the City of Tigard. 1.3 Coordination The initial coordination meeting was held on September 9, 1976, and attended by representatives of the Federal Emergency Management Agency, the City of Tigard, and the study contractor. The purpose of the meeting was to identify stream reaches to be studied, explain the study concepts, identify data sources, and establish communica- tion and coordination procedures. An intermediate coordination meeting was held in Tigard in July 1980 to allow local officials to review plan and profile drawings showing water-surface profiles, floodway delineations, and flooded- area outlines. The final coordination meeting was held on April 9, 1981, and was attended by city residents and representatives of the Federal Emergency Management Agency, the study contractor, and the city. All problems raised at the meeting were resolved. 2.0 AREA STUDIED 2.1 Scope of Study This Flood Insurance Study covers the incorporated areas of the City of Tigard, Washington County, Oregon. The area of study is shown on the Vicinity Map (Figure 1) . Unincorporated areas of Washington County within the City of Tigard were excluded from this study. A detailed study was made of flooding from Tualatin River, Fanno Creek, Ash Creek, and Summer Creek within the Tigard corporate limits. Approximate methods were used use to study Hiteon Creek, a small tributary to Fanno Creek on the northwestern edge of Tigard near Scholls Ferry Road/State Route 210. Those areas studied by detailed methods were chosen with considera- tion given to all proposed construction and forecasted development through 1985. Approximate analyses were used to study those areas having a low development potential or minimal flood hazards. The scope and methods of study were proposed to and agreed upon by the Federal Emergency Management Agency and the City of Tigard. 2.2 Community Description Tigard is in the southeast corner of Washington County, in northwest Oregon. It is approximately 8 miles southwest of Portland, Oregon. Tigard is adjacent to the City of Beaverton to the north and the City of Durham to the south. Unincorporated areas of Washington County also border Tigard, and there are some small county areas within the city. Tigard was incorporated in 1961, and its population grew from 4,302 in 1970 to an estimated 13,500 in 1978 (Reference 1) . All of the streams considered under this study are part of the Tualatin River drainage basin. Tualatin River originates in the Coast Range at an elevation of 3400 feet. The basin has an area of 711 square miles, is oval in shape, and is approximately 40 miles long and 25 miles wide. Fanno Creek, a tributary to Tualatin River, drains 13 square miles upstream of Tigard. It originates in the west hills of Portland. The stream flows generally southeasterly through Tigard. Ash Creek, a tributary to Fanno Creek with a 4-square-mile drainage area, flows southwesterly. Summer Creek, also a tributary to Fanno Creek, flows easterly as it drains 5 square miles. Fanno, Summer and Ash Creeks are crossed by numerous bridges and culverts within the Tigard corporate limits. 2 P. BEAVERTON iall•It...°-.AO.°'.° .'' N 1 . -----..,:•:•.....:•:•:•:•:•::::::::::::::::K;f: . .: li , , , ,f = : ERR ' '04� `' v�MULCKAM H CO. v t::::-.a.. ' ...;._ CLACKAMAS 60. v CIA 4 Cr 4 a ROAD LL V� � + r�►�,ALO ST r� ` ® `, CARTER gr �"''''� o �..�.T1 SW BULL O 1 �: f P.` w+ ,BONITA RD { ao _ I . ADP �ENl'D KING 1_....._.. / URMOAM /0`..., Q►p''��. SW Y. *:::g.�1TY' •• i til v /fl 'R�VER I TUALAT/N c° LAKE ,OSWEGO all W X an eUTHER fIIIr- F -.e FEDERAL EMERGENCY MANAGEMENT AGENCY APPROXIMATE SCALE Ca 4000 H F 0 4000 8000 12000 FEET CITY OF TIGARD, OR rri (WASHINGTON C®.) VICiNITY MAP Economic activity in Tigard is diversified and growing. Industrial facilities in the community are varied and are located along Pacific Highway West (State Highway 99W) and State Highway 217. Commercial development is located primarily along Pacific Highway West and SW Main Street. Residential development in Tigard is mostly west of Fanno Creek. Important transportation routes in the city are Pacific Highway West, State Highway 217g Hall Boulevard, and the Burlington Northern and Southern Pacific Railroads. The flood plains of several areas along the stream reaches studied are under- going development. One such area is along Summer Creek between SW 113th and SW 121st Avenues, where several residences are in the flood plain. Another flood-prone area includes commercial and residential development along a 1-mile reach of Fenno Creek from Pacific Highway West upstream to SW. Tiedeman Avenue. The climate in Tigard consists of warm, dry summers and mild, wet winters. Temperatures are usually moderate, ranging from an average January minimum of 25°F to an average July maximum of -81°F (Reference 2) . The average annual precipitation is nearly 45 inches, with 78 percent of the precipitation falling from October to May. Snowfall occurs on only a few days each year; snow on the,ground is generally of short duration, with depths seldom exceeding 6 inches (Reference 3) . Soils in and around the City of Tigard are silt loams on nearly level to steep slopes. Drainage characteristics for those soils are poor along the Summer Creek and Fenno Creek flood plains, but drainage improves on sloping terrain. Trees, grass, and shrubs are the dominant vegetation types. The incorporated area is being rapidly urbanized. 2.3 Principal Flood Problems Tualatin River, Fanno Creek, Ash Creek, and Summer Creek flooding is generally caused by rainstorms in the winter, the period of greatest storm activity. Floods rise quickly following a heavy rainstorm and usually last less than 1 day on Fanno Creek and one-half day on Ash and Summer Creeks. Flooding in Tigard is not well documented. The largest flood on Fanno, Ash, and Summer Creeks during the last 10 years occurred in December 1977. Although stream gage records are not available, it is estimated that the 1977 flood recurrence interval was approxi- mately 10 years for those three streams. Flood damages in Tigard were light because the areas susceptible to flooding were generally known and development was avoided. Flooding along Summer Creek is accentuated by a high ground water table, which causes nuisance flooding to numerous residences. Figure 2 shows the heights that would be expected from 100- and 500-year floods on Fanno Creek. Figure 3 shows flooding in Tigard from Summer Creek in December 1977. 4 o I u )iJ] ,its T, ;ril ., 't 1, ",i � r, _.r4 1°-—L g' 100 YE AC FE 001) � `47 w"...„,,,,. ................r J.VW 114 1111=1,1111■1 sit7.0.................. ••••••••••.a••■•••■••••■• •.... t r• 7. r t F r, , I r- ''''.17• "4 C t„11'. r r''•�xr 2„t1. t4 a "t;, r ^+' M s K ,• 1 «t .,% 4.0-ii .;a 5 kt ilia •,- -maw.- i ''v 1 . ”".,. `«�,, '. ,.,ti" , ' .4 i { .. . rv'.k'FF f�.',`[ �-,-y nL ,V f�.J. 3,.. to 4 ;i . r' �t ,; R •V r s',...: t yy°,��- 1Y' y ,I'. : bt l f I jr'.nt.. t� :-.. ` 'et k ✓ Y ' � , " t• d� a• ?;,t1''„ i !! I r � `a ` 1}a .f a P ` -1, .. • • -, 1, +, 4, ' 1..,,V,re , • ,. r liblzi;iiir"..,iiiiiik, .1',7- illi11 ri►lt . r Figure 2. Expected Future Flood Heights of Fanno Creek at SW Grant Avenue fit 'r r.... aY d Y 't /407.C,• d T^� $ h � �ti� Y1Yt� ° tr i ..;,:f0-2,- O , . v. , .t 4W , a r g�i y-i uvt r k b t441 xuJ'} r Vt `}' r''�4.0. ,e4 iS . Jnft .yT' P.: :;'44 s� r ' a A _..n.Y,. • ^.!.....ar+._._..:»a i'' T.-4,z.'s -. `: '..S .. + mo' t u r Y+ .•=� � .° 3• 1 6 q a ,;-L•L,N.Y +.4'..71:'•,,t 4t ..y;r fMr yr,, s ��"y am y • V" -1 d y t, - °ro, da• - ■ Figure 3. December 1977 Summer Creek Flooding at SW 116th Street 5 2.4 Flood Protection Measures The Tualatin River basin has one multipurpose flood control storage project, Henry Hagg Lake Project, located upstream of the City of Tigard. The project was contructed by the U.S. Water and Power Resource Service, previously known as the U.S. Bureau of Reclamation. That project began operation during the 1974-1975 flood season. It provides 30,000 acre-feet of flood storage starting in November each year. Flood storage capacity is reduced as the winter flood season terminates and the reservoir is filled each spring in antic- ipation of the summer irrigation demand. There are no flood control structures within the Tigard corporate limits. However, non-structural measures of flood protection are being used to aid in prevention of future flood damage. These are in the form of a flood hazard zoning ordinance for controlling development within the 100-year flood plain. In addition, the city requires building permits for construction and reviews those permits to assure that sites are reasonably safe from flooding. 3.0 ENGINEERING METHODS For the flooding sources studied in detail in the community, standard hydrologic and hydraulic study methods were used to determine the flood hazard data required for this study. Flood events of a magnitude which are expected to be equalled or exceeded once on the average during any 10-, 50-, 100-, or 500-year period (recurrence interval) have been selected as having special significance for flood plain management and for flood insurance premium rates. These events, commonly termed the 10-, 50-, 100-, and 500-year floods, have a 10, 2, 1, and 0.2 percent chance, respectively, of being equalled or exceeded during any year. Although the recurrence interval represents the long term average period between floods of a specific magnitude, rare floods could occur at short intervals or even within the same year. The risk of experiencing a rare flood increases when periods greater than 1 year are considered. For example, the risk of having a flood which equals or exceeds the 100-year flood (1 percent chance of annual occurrence) in any 50-year period is approxi- mately 40 percent (4 in 10) , and, for any 90-year period, the risk in- creases to approximately 60 percent (6 in 10) . The analyses reported here reflect flooding potentials based on conditions existing in the community at the time of completion of this study. Maps and flood eleva- tions will be amended periodically to reflect future changes. 3.1 Hydrologic Analyses Hydrologic analyses were carried out to establish the peak discharge- frequency relationships for floods of the selected recurrence intervals for each flooding source studied in detail affecting the community. Tualatin River stream-gage records were statistically analyzed, using the log-Pearson Type III distribution as outlined by the U.S. Water Resources Council (Reference 4) . Discharge-frequency 6 curves for the U.S. Geological Survey stream gages at West Linn, Dilley, and Farmington were developed using records from 1938 to 1976, 1940 to 1975, and 1939 to 1958, respectively. Due to the relatively short record, Farmington gage data were adjusted by use of the long-term station data at West Linn. All downstream discharges were adjusted for flood control furnished by Henry Hagg Lake Project. There are no stream-gage stations on Fanno Creek, Ash Creek, or Summer Creek. The U.S. Soil Conservation Service method for rainfall- runoff and unit hydrograph determination (Reference 5) was used in conjunction with U.S. Army Corps of Engineers computer programs (References 6 and 7) for hydrograph computing, combining, and routing to generate flood hydrographs for selected recurrence intervals on Fanno Creek, Summer Creek, and Ash Creek. Peak discharge-drainage area relationships for Tualatin River and Fanno, Ash, and Summer Creeks are shown in Table 1. 3.2 Hydraulic Analyses Analyses of the hydraulic characteristics of the flooding sources studied in the community were carried out to provide estimates of the elevations of floods of the selected recurrence intervals along each of these flooding sources. Hydraulic analyses were performed using the U.S. Army Corps of Engineers HEC-2 step-backwater computer program (Reference 8) . Cross sections for Tualatin River, Fanno Creek, Ash Creek, and Summer Creek were composites of data from U.S. Army Corps of Engineers field surveys obtained in 1977 and City of Tigard topographic maps (Reference 9) . All bridges, dams, and culverts were field checked to obtain elevation data and structural geometry. Locations of selected cross sections used in the hydraulic analyses are showy on the Flood Profiles (Exhibit 1) . For stream segments for which a floodway is computed (Section 4.2) , selected cross section locations are also shown on the Flood Boundary and Floodway Map (Exhibit 2) . Hydraulic roughness values (Manning's "n") for the channel and overbanks were first estimated from field observation. The "n" values for Tualatin River ranged from 0.048 to 0.050 and from 0.095 to 0.120 for the channel and overbank, respectively. The "n" values for Fanno Creek were modified, when necessary, to match the high-water profile of the December 1977 flood. The final calibrated "n" values for Fenno Creek in this study varied from 0.042 to 0.065 for the channel and from 0.075 to 0.110 for the overbank. Ash Creek"n" values ranged from 0.052 to 0.062 and from 0.065 to 0.180 for the channel and overbank, respectively. Summer Creek "n" values ranged from 0.045 to 0.080 and from 0.075 to 0.300 for the channel and overbank, respectively. 7 - I Table 1. Summary of Discharges I! Drainage Area Peak Discharges (Cubic Feet per Second) • I Flooding Source and Location (Square Miles) 10-Year 50-Year 100-Year 500-Year Tualatin River At Washington Clackamas County Line (River Mile 8.8) 686 15,100 23,000 29,500 41,000 II Fanno Creek At SW Durham Road 31 2,900 3,800 4,200 5,100 At SW Tiedeman Avenue 24 2,750 3,500 3,850 4,700 At SW Dakota Street 17 1,900 2,450 2,700 3,250 Ash Creek At Mouth 4.1 750 950 1,000 1,250 Summer Creek At Mouth 6.2 1,050 1,300 1,450 1,750 ao At SW 135th Avenue (Outside Corporate Limits) 4.0 800 1,000 1,100 1,350 Flood profiles were drawn showing computed water-surface elevations to an accuracy of 0.5 foot for floods of the selected recurrence intervals (Exhibit 1) . Starting water-surface elevations for Tualatin River were obtained from a hydraulic analysis for the West Linn Flood Insurance Study (Reference 10). Starting water-surface elevations for Fanno Creek in Tigard were obtained from a hydraulic analysis performed by the U.S. Army Corps of Engineers for the Washington County Flood Insurance Study (Reference 11) . Starting water-surface elevations for Ash and Summer Creeks were based on normal depth calculations. Approximate flooding for Hiteon Creek was taken from flood plain delineation maps published by Washington County (Reference 12). All elevations are referenced to the National Geodetic Vertical Datum of 1929 (NGVD) . Elevation reference marks used in the study are shown on the maps. The hydraulic analysis for this study is based on unobstructed flow. The flood elevations shown on the profiles are thus considered valid only if hydraulic structures remain unobstructed and operate properly. 4.0 FLOOD PLAIN MANAGEMENT APPLICATIONS The National Flood Insurance Program encourages State and local governments to adopt sound flood plain management programs. Therefore, each Flood Insurance Study includes a flood boundary map designed to assist com- munities in developing sound flood plain management measures. 4.1 Flood Boundaries In order to provide a national standard without regional discrimina- tion, the 100-year flood has been adopted by the Federal Emergency Management Agency as the base flood for purposes of flood plain management measures. The 500-year flood is employed to indicate additional areas of flood risk in the community. For each stream studied in detail, the boundaries of the 100- and 500-year floods have been delineated using the flood elevations determined at { each cross section; between cross sections, the boundaries were interpolated using topographic maps at a scale of 1:4800, with a contour interval of 4 feet (Reference 9) . The approximate 100-year flood boundaries for Hiteon Creek, a tributary to Fanno Creek in northwest Tigard, were obtained from flood plain delineation maps published by Washington County (Refer- ence 12) . 9 Flood boundaries for the 100- and 500-year floods are shown on the Flood Boundary and Floodway Map (Exhibit 2) . In cases where the 100 and 500-year flood boundaries are close together, only the 100-year flood boundary has been shown. Small areas within the flood boundaries may lie above the flood elevations and, there- fore, not be subject to flooding; owing to limitations of the map scale, such areas are not shown. 4.2 Floodways Encroachment on flood plains, such as artificial fill, reduces the flood-carrying capacity, increases the flood heights of streams, and increases flood hazards in areas beyond the encroachment itself. One aspect of flood plain management involves balancing the economic gain from flood plain development against the resulting increase in flood hazard. For purposes of the National Flood Insurance Program, the concept of a floodway is used as a tool to assist local communities in this aspect of flood plain management. Under this concept, the area of the 100-year flood is divided into a floodway and a floodway fringe. The floodway is the channel of a stream plus any adjacent flood plain areas that must be kept free of encroachment in order that the 100-year flood may be carried without substantial increases in flood heights. Minimum standards of the Federal Emergency Management Agency limit such increases in flood heights to 1.0 foot, provided that hazardous velocities are not produced. The floodways in this report are presented to local agencies as minimum standards that can be adopted or that can be used as a basis for additional studies. The floodways presented in this study were computed on the basis of equal conveyance reduction from each side of the flood plain. The results of these computations were tabulated at selected cross sections for each stream segment for which a floodway was computed (Table 2). As shown on the Flood Boundary and Floodway Map (Exhibit 2) , the floodway widths were determined at cross sections; between cross sections, the boundaries were interpolated. In cases where the boundaries of the floodway and the 100-year flood are either close together or collinear, only the floodway boundary has been shown. The area between the floodway and the boundary of the 100-year flood is termed the floodway fringe. The floodway fringe thus encompasses the portion of the flood plain that could be completely obstructed without increasing the water-surface elevation of the 100-year flood more than 1.0 foot at any point. Typical relation- ships between the floodway and the floodway fringe and their signi- ficance to flood plain development are shown in Figure 4. 10 BASE FLOOD FLOODING SOURCE FLOODWAY WATER SURFACE ELEVATION SECTION MEAN WITHOUT WITH CROSS SECTION DISTANCE 1 WIDTH AREA VELOCITY REGULATORY FLOODWAY FLOODWAY INCREASE (FEET) (SQUARE (FEET PER (FEETNGVD) FEET) SECOND) Tualatin River A 9.84 1,218/2 1,100 _ 16,236 1.8 126.4 126.4 127.3 0.9 B 10.20 1,592/310 14,708 2.0 126.7 126.7 127.6 0.9 Fanno Creek A 1.11 78 698 6.0 125.8 123.7 128.7 0.4 B 1.44 89 761 5.5 128.3 128.3 C 1.53 265 1,783 2.3 130.0 130.0 130.7 0.7 . D 2.41 250 1,556 2.7 133.8 133.8 134.5 0.6 E 2.69 90 903 4.6 136.9 136.9 137.5 F 2.80 220 1,621 2.5 137.7 137.7 138.3 0.6 G 3.34 400 2,412 1.7 140.0 140.0 140.6 0.6 H 3.68 320 1,730 2.4 141.1 141.1 141.7 0.6 1 3.86 280 1,379 3.0 141.9 141.9 142.5 0.6 J 4.16 260 1,960 2.1 145.9 145.9 146.4 0.5 K 4.50 240 1,517 2.7 146.8 146.8 147.4 0.6 L 4.73 440 2,010 2.0 14P.0 148.0 145.6 0.6 M 4.81 73 501 8.1 151.0 151.0 151.2 0.2 N 4.86 101 843 4.8 152.8 152.8 152.9 0.1 0 4.93 195 1,487 2.7 153.6 153.6 153.7 0.1 P 5.07 I 55 613 6.6 153.9 153.9 154.1 0.2 4 5.21 280 2,507 1.6 154.6 154.6 155.4 0.8 R 5.67 400 2,617 1.5 155.3 155.3 156.0 0.7. S 5.83 60 2 546 7.1 156.2 156.2 156.6 0.4 T 6.35 117/902 744 3.6 160.1 160.1 160.5 0.4 U 6.58 300/215 2,298 1.2 16.0.5. 160.5 161.2 0.7 I; V 6.85 310 1,997 1.3 160.8 160.8 161.5 0.7 W 7.09 , 160 I 1,103 2.4 161.4 161.4 162.2 0.8 1 'Miles Above Mouth 2Width/Width Within Corporate Limits 3Elevation Computed Without Consideration of Backwater From Tualatin River FEDERAL EMERGENCY MANAGEMENT AGENCY a FLOODWAY DATA U w CITY OF TIGARD,OR n, TUALATIN RIVER-FANNO CREEK N (WASHINGTON CO.) 4 I BASE FLOOD FLOODING SOURCE FLOODWAY WATER SURFACE ELEVATION WITHOUT WITH SECTION MEAN (REGULATORY FLOODWAY I FLOODWAY I INCREASE WIDTH AREA VELOCITY CROSS SECTION BISTANCE (FEET) (SQUARE (FEET PER (FEET NGVD) FEET) SECOND) i A 0.10 47 Ash Creek 183 5.6 160.1 155.82 2 156.4 0.6 1 B 0.40 95 477 1.9 160.2 160.2 161.0 0.8 C 0.49 35 231 3.9 160.6 160.6 161.5 0.9 C Summer Creek 561 2.6 157.1 154.92 155.5 0.6 A 0.30 120 B 0.30 89 351 4.1 157.3 157.3 158'.1 0.8 161.8 161.8 162.5 0.7 180 687 2.1 C 0.76 120 346 4.1 168.0 168.0 168.7 0.7 D E 1 1.13 1.07 125 688 2.1 169.0 169.0 169.5 0.5 E 165 1,045 1.3 169.5 169.5 170.1 0.6 F 1.30 65 267 5.0 171.1 171.1 171.1 0.0 B 1.50 55 569 G 1. 0 2.2 171.7 171.7 172.0 0.3 I 1.51 60 550 2.3 171.7 171.7 172.1 0.4 3 554 2.3 171.7 171.7 172.2 0.5 K I, 1.74 195 585 2.0 172.5 172.5 173.3 0.8 K 1.74 'Miles Above Mouth 2Elevatian Computed Without Consideration of Backwater From Fanno Creek I lumwma■ FEDERAL EMERGENCY MANAGEMENT AGENCY 1 FLOODWAY DATA CO CITY OF TIGARD,OR ASH CREEK° SUMMER CREEK rro (WASHINGTON CO.) Q; ei 100•YEAR FLOOD PLAIN L4 FLOODWAY FLOODWAY FRINGE l 4 FLOODWAY FRINGE STREAM--i CHANNEL FLOOD ELEVATION WHEN CONFINED WITHIN FLOODWAY ENCROACHMENT ENCROACHMENT SURCHARGE a4H I+++ear war B A AREA OF FLOOD PLAIN THAT COULD FLOOD ELEVATION BE USED FOR DEVELOPMENT BY BEFORE ENCROACHMENT RAISING GROUND ON FLOOD PLAIN LINE AB IS THE FLOOD ELEVATION BEFORE ENCROACHMENT. LINE CD IS THE FLOOD ELEVATION AFTER ENCROACHMENT. *SURCHARGE IS NOT TO EXCEED 1.0 FOOT'(FEMA REQUIREMENT)OR LESSER AMOUNT IF SPECIFIED BY STATE. Figure 4. Floodway Schematic 5.0 INSURANCE APPLICATION In order to establish actuarial insurance rates, the Federal Emergency Management Agency has developed a process to transform the data from the engineering study into flood insurance criteria. This process includes the determination of reaches, Flood Hazard Factors (FHFs) , and flood insurance zone designations for each flooding source studied in detail affecting the City of Tigard. 5.1 Reach Determinations Reaches are defined as lengths of watercourses having relatively the same flood hazard, based on the average weighted difference in water-surface elevations between the 10- and 100-year floods. This difference does not have a variation greater than that indicated in the following table for more than 20 percent of the reach: Average Difference Between 10- and 100-Year Floods Variation Less than 2 feet 0.5 foot 2 to 7 feet 1.0 foot 7.1 to 12 feet 2.0 feet More than 12 feet 3.0 feet 13 The locations of the reaches determined for the flooding sources of Tigard are shown on the Flood Profiles (Exhibit 1) and summarized in Table 3. 5.2 Flood Hazard Factors The FHF is the Federal Emergency Management Agency device used to correlate flood information with insurance rate tables. Correla- tions between property damage from floods and their FHF are used to set actuarial insurance premium rate tables based on FHFs from 005 to 200. The FHF for a reach is the average weighted difference between the 10- and 100-year flood water-surface elevations expressed to the nearest one-half foot, and shown as a three-digit code. For example, if the difference between water-surface elevations of the 10- and 100-year floods is 0.7 foot, the FHF is 005 if the difference is 1.4 feet, the FHF is 015; if the difference is 5.0 feet, the FHF is 050. When the difference between the 10- and 100-year water-surface elevations is greater than 10.0 feet, accuracy for the FHF is to the nearest foot. 5.3 Flood Insurance Zones After the determination of reaches and their respective FHFs, the entire incorporated area of Tigard was divided into zones, each having a specific flood potential or hazard. Each zone was assigned one of the following flood insurance zone designations: Zone A: Special Flood Hazard Areas inundated by the 100-year flood, determined by approximate met__hods; no base flood elevations shown or FHFS determined. Zones Al, A3, and All: Special Flood Hazard Areas inundated by the 100-year flood, determined by detailed methods; base flood elevations shown, and zones subdivided according to FHFs. Zone B: Areas between the Special Flood Hazard Areas and the limits of the 500-year flood, including areas of the 500-year flood plain that are protected from the 100-year flood by dike, levee, or other water control structure; also areas subject to certain types of 100- year shallow flooding where depths are less than 1.0 foot; and areas subject to 100-year flooding from sources with drainage areas less than 1 square mile. Zone B is not subdivided. 14 ELEVATION DIFFERENCE FLOOD BASE FLOOD 1 BETWEEN I% (100-YEAR) FLOOD AND HAZARD ZONE ELEVATION 3 rn".""ualw"lgmm.""g"""m8R'gm7 SOURCE PANE:L i0% 2% 0.2%, FACTOR (FEET lEWD) (10-YEAR) (50-YEAR) (500-YEAR) 0003,0005 -1.4 -0.4 0.9 015 A3 Varies - See Map 0003 -0.6 -0.2 0.5 005 Al Varies - See Map Summer Creek Reach 1 . 0002,0003 -0.7 -0.2 0.5 005 Al Varies See Map Tualatin River Reach 1 0005 -5.46 -1.86 3.67 055 All Varies - See Map 1Flood Insurance Rate Map Panel 2weighted Average 3Rounded to Nearest Foot FEDERALEMERGENCY MANAGEMENTAGENCY FLOOD INSURANCE ZONE DATA co � r U CITY OF TIGARD,OR FANNO CREEK-ASH CREEK- (WASHINGTON(WASHINGTON CO.) SUMMER CREEK-TUALATTIV RIVER -- m ; Zone C: Areas of minimal flooding. The flood elevation differences, FHFs, flood insurance zones, and base flood elevations for each flooding source studied in detail in the community are summarized in Table 3. 5.4 Flood Insurance Rate Map Description The Flood Insurance Rate Map for the City of Tigard is, for insurance purposes, the principal result of the Flood Insurance Study. This map (published separately) contains the official delineation of flood insurance zones and base flood elevation lines. Base flood elevation lines show the locations of the expected whole foot water-surface elevations of the base (100-year) flood. This map is developed in accordance with the latest flood insurance map preparation guidelines published by the Federal Emergency Management Agency. 6.0 OTHER STUDIES Flood Insurance Studies are being prepared for the adjacent Cities of Durham, Beaverton, and Tualatin (References 13, 14, and 15) and the unincorporated areas of Washington County (Reference 11) , including the areas adjacent to Tigard. The results of the Durham, Beaverton, Tualatin, and Washington County Flood Insurance Studies will match exactly with this study. A Flood Hazard Boundary Map for Tigard (Reference 16) has been published. This Flood Insurance Study is more detailed; thus, it supersedes that map. In 1969, the U.S. Army Corps of Engineers prepared a Flood Plain Infor- mation (FPI) report for Washington County (Reference 17) . The 100-year flood profile presented in the FPI report varies within approximately 1 foot from the 100-year profile for this study through the City of Tigard. The difference in flood heights is attributed to improved data obtained for this study. This study will supersede all previous U.S. Army Corps of Engineers flood hazard studies. This study is authoritative for the purposes of the National Flood Insur- ance Program; data presented herein either supersede or are compatible with all previous determinations. 7.0 LOCATION OF DATA Survey, hydrologic, hydraulic, and other pertinent data used in this study can be obtained by contacting the Insurance and Mitigation Division, Federal Emergency Management Agency, Federal Regional Center, 130 228th Street, SW., Bothell, Washington 98011. 16 8.0 BIBLIOGRAPHY AND REFERENCES 1. Portland State University, Population Estimates: Oregon Counties and Incorporated Cities, July 1978 2. Pacific Northwest River Basins Commission, Climatological Handbook, Temperature, Volume 1, Part A, 1969 3. Pacific Northwest River Basins Commission, Climatological Handbook, Precipitation, Volume 2, 1969 4. U.S. Water Resources Council, "Guidelines for Determining Flood Flow Frequencies," Bulletin 17, April 1976 5. U.S. Department of Agriculture, Soil Conservation Service, SCS National Engineering Handbook, Section 4, Hydrology, January 1971 6. U.S. Department of the Army, Corps of Engineers, Hydrologic Engi- neering Center, Unit Graph and Hydrograph Computation, Computer Program 23-J2-L228, Davis, California, July 1966 7. U.S. Department of the Army, Corps of Engineers, Hydrologic Engi- neering Center, Hvdr graphic .Combining and Routings, Computer Program 23-J2-L232, Davis, California, August 1966 8. U.S. Department of the Army, Corps of Engineers, Hydrologic Engineering Center, HEC-2 Water Surface Profiles, Generalized Computer Program, Davis, California, November 1976, updated October 1977 9. City of Tigard, Oregon, Topographic Maps, Scale 1:4800, Contour Interval 4 feet; Aerial Mapping Company of Oregon, 1974 10. U.S. Department of Housing and Urban Development, Federal Insurance Administration, Flood Insurance Study, City of West Linn, Clackamas County, Oregon, March 15, 1977 11. Federal Emergency Management Agency, Flood Insurance Study, Washington County, Oregon (Unincorporated Areas) , unpublished 12. Washington County, Oregon, Department of Public Works, "Flood Plain Delineation Maps," 1974 13. Federal Emergency Management Agency, Flood Insurance Study, City of Durham, Washington County, Oregon, unpublished 14. Federal Emergency Management Agency, Flood Insurance Study, City of Beaverton, Washington County, Oregon, unpublished 17 MOP 15. Federal Emergency Management Agency, Flood Insurance dy ity Stu , C of Tualatin, Washington County, Oregon, unpublished 16. U.S. Department of Housing and Urban Development, Federal Insurance Administration, Flood Hazard Boundar Ma., Cit of Ti•ard, Ore.on, 1:9600, February 14, 1978 17. U.S. Department of the Army, Corps of Engineers, Portland District, "Floodplain Information, Washington County, Oregon," June 1969 1 18 . I NmnNN1U1UUau1 UNmt 01 u■1a/■■■ „N■NEU11■■ NEN1nuNEMSESi MENEMEeef■°iwB°NNai■N°r.NNUiiiRE°°aattt ■mmtt=iwNawm alml�NUE ---Nr\MMMee tlN r = MNS. m NmNNNE NNN N ■ If a n°N°nu°uu°°ii mosmisiiiii ua111uouENm 1NUanoal=a°�°■wuwuoa • mamml■aU1Nn111111eamofl i11111Ue1m■N1111sm=Im N■mmspommeiiimaiii mMMMMMMmisMitwuneewel■ eeaasaeliN°■ iii _� ff11NmNNamEN1NtNltNrfmttNNf1NENNm1■ MENNNINU 1UUN1m1tmNN/mtf■ NNUN1mNnnN Ea1N 111■E1emEem1E111111�ie111f1eee/uE1111efa1111/111m11NEHNe1m■1unNEMEMO■eeEmm■Efemmml/E1E111ne1a1aE1NN1m NansN■uNUUSauNnusannNUUaesnnNUOmue iumsey�rtou°unmUN�maNENNfNeuN1N/tsNUNUUnufoaunrNN • ' N°1uN°nNf ut7r °°°N ■C w11 11 imlmNmmn U11N000U•UNUUN I • _ MUMS 1U 11m NUUamIIIim1lmEmeaeEmllemmteem/m1Emm■1aa111msamms s■r mMMMMM MMMM°a°°f°°°°1°f°°°°°°°°°°°°f°a°t°SNSNMMMMNMNf°Ntaa°1 i °NE■■tE1m■11eaEEarla°memo■efmmes■°°oohs■mlamusmutea°°■mmlatom■°°°°11MMse mMMMMMumMMMMMMMMMMMimm NasN11/mt■MMMMMMMsum m ■NN1 EN1 eUU■NUNUEMINENm■1me1NNSEEMMENSESEVNNNEMMM111aUNt1EE3■■NmmslNweEla°°°aEEela■eEm■Nmam■■1111■sE1111■111ma1aamoEmMMMMM ° u1NN[•• • soma °°NNU°■!!e IX a map ow - N ✓ ma MM• MMMMMM��� 1NNUNNUNU■NNN7•NNMMMMMMUlnwmUUUNUNUOaMMEMOM NUEm000npnnnonUIUNUUNI N°°NtNMM s W ee°°°r°°■amf°NNa°°N°emm nEMM MMMMSEENENSMENamnmmt111mt■eeeEMENMM1t■1■mm■EU11a11■MMMMMM1°°°°°°°°1/m1N11/NMMMMMMMMMMMMMMMMMMm1NEMMEN ■ °leUlNUmmE•nMMM MMMMNENmNN°°UM1U1EUmUSfIUUM■Na°!°Nm1■oaUU■fN■NN■nnennnoUlnnnNEU■NESSENNUUhN d 1- • • Ui®-._�ee■■NU°N■■°N°N MOM CM 130.�WdfftUffmN / C _ MOONS CD 4 • mn H Ewa MMM 111°11//N111NS1MMM MMM1a/1nMESMMMMMas111/m1N1■/HEMS■ENN1am 1e1SEMENNEEN11111a°°°°°1me1ENm11meNSESEM11NEMENEM ENSEMEMEIaEmN■ EMS ••e_1 • 1:;:■ • z 15 msm1/1waNNnun°NN000Unaln■NNnuomnunl°Uo1Nmm01U1Uan■ne°NUtuuUN N°Nn°/UUSn°uunesMMMiii ■■� _e_eas.� ✓ somo a •seem-sr—rasa W = nMEME NM MMMMMM°°°t°°°°°°°e°1°■°°MMMMNE°■e°°■°°°SEENENES tinNNE ENS°°°e°°N EMENE°r°1°e■°°E°1e■°°e°N°nea■°°a°°°■en°°e■° w /ENNON/Nn a. ESEEMEMENEMENNESMNESSEENN1EE■N■EeeEENENNE1/111■MESS ENEe11e_°EMENn11EEMENNENNENNESENEEN.NEeslNNSENEMENNESMMMMMNMM MMEU MESS ip• ■fNm1a■ftmlUaNO1�m8iaim miaiaimN/m11wi1aa//NNNta1�� NNNEN skr uolunonnu°°ouNUtuN°N■nueuo°ueNNw°w°ut°n°= uu°SEMNm1 'I e m°°°°a°■°11°°°a1a°°1mm om emsa°a°°s°■ama/aea°momm um°°°■°°°°°■e°°°°°e°°°°°aE°1111■e°a°°°■°e°■a mourn M1°°f°°fN �. /M4AIv� rms ummumm 11°°t°°°ea°°°°°°°a■°SEMENN°■°°t°1°e°°°1u°°°°1N°°°111°°°°°°E SES MM°°f°°af°°°°°■°°°E°°°1n■°°E:e°°I°■N°°e■°°°°N■ 100:r��1y 1t/NtamNm n N aUYma11e11N1e11en 11eN11emee1el■1l1■EUawlamtnapm/1m/1/Nmm r ■4JO11NUn1teNa1E11NU11m 1lm1UN11N1UEa� NUNU/N w PM UMENENEMENNUN c7 O■EN•ENN ■ NONSENSE Isom of N. t1�NNwNiie°uuU1o®runeminnuu■ueuNlly,i�teNU■N1aNUUNNUO 2 MEMENSw•E/ -v m =am1/N°°U°UUNNM w fe ° NeU1■meNmlNe SUNRImU1mf �►w■R ENE ° ■ �tftfNE/Uf ai C •O UNU.UNNNUAUUEMEE m•ULc U ._NmU°U°tn°U°1NmN°m000°UNN 0 C V 95 ' N IINNU.NmNUU1m,.N1°NmsMMMMtMmasta .VNrg_ =1N a nm00'0l01UN•UI000 1UNU■ENmm1m' LEGEND Zp."0 lUtlU1E1NNNE °■ ■ F Q 1N°NatM�mEryNNENENa/AMENOME 11N1NNU1Ne1em■Em11\�l1UN1U11aNMUNEHENEEMMEVEUENMMMMM f°MMMEN' 4 n K NNU■N.NNN� >NUtllt.N000NUNIENNNUUMMMMMM a■n°°; 500.VEAR FLOOD f F2 wan Nm ■m■m°INUNUnNa1U.000Un■UNm MMboutNNmN110 - 190-VEAR FLOOD > 1-2 . m wnN1eS = 1 'i .ZI — 50-YEAR FLOOD Z oa . sa AiMt1U°N�iir fU°W ff/UNsENN :UNU MIl=Nm 10.YEAR FLOOD W — 1UUW- MW STREAM BED M\NNEMMMMMM111UUpmN�E=1 m.m1111U1n11Eea11U■NMMMMM/1MEER '.1 NS MMMM.l.NENNENUIMENNEMEMOV VEENES/NEMMMMMMP,\1lemaeeUU IX EMOUNENNem■a1NEaa1EauNESMMMMMMM SEMEN C UNfaN CROSS SECTION w •O• Om• m1SEE00=0S0 1mme°m=11mIIMINNMMMMiiiii°mmommoslidg1■m1=N1N■m/mao=1 m11111Elm1■s=N1lammrsam1Em111aml LOCATION w NNf m1 9.2 9A 9.6 98 10.0 10.2. 10.4 10.6 . STREAM DISTANCE IN MILES ABOVE MOUTH 01P I ' 1M- � t ;'�y U I 1.jy�jr■Nluum\/C IM CCCMUM WE CC�'Cilr\\CCCNNS\■uufuuulausCliiiC° 1\fn\■NiN■yuuuN ow■InNRN_- -°_--1 wwul - ■MI^°: viii �1■Oi/NNN \fNlNllIMfNU i1NNUi•\i• °°-� H�---~---rA i\i■iiiiii■u\NCi m/■li BREW ■...: \1■\\!1M\\1M\f■1\lfN� ■■■■1\■■■1■■I�11■■■\\■■■11\1Nw\■1\lm �1\1 i moss ■fW■!!■\■R■\1■N■■■1■■/■■r!■■M■f!f■!1■O\!r■!!//\!!1!!!f\!■\■f■\\!■■1■!fl■■!\■f■!■\!!!■!N!!\■!.0■■!■!■■I/\N■■ M�r+N\\■M L'ofr■M\4N■MNr\■■■INNNM■N■■WNWUROMUNOM:V1M■M■■N■HN • 1fH\ll ■rNl•: . 145 me,.. H=■N■N■w!f■■Lt\■■//■ms ,. M �p 1'!r■f\ ■!N■N \1■r■■AAMMM1■■\f\■■\1■1\■r■■ff 1■!■tRt3rf■■!1[R!!/■■■■\f■r\!l� �If■1■■N\■■■\\!■1!\t■!M■■!\lf■rl■\■fll■\\f■■1■ Nb 1 ■■■Ni• ■■■ru■11■■1\.. NF V •uowmuf. CHNe�IiNMNUN■!:/!!uu■MN\111cnmiiCCNnnMMNMMM■R /MNH■H■■C RR ■ ■■■■t ■■■■■ ■\L �U\■!f■!NM! \1NN411 M3H\NlfR.U.UNN■!■■r. lf•NUN\f■1\■■MRMMN■NHMHr/r\N■H111M • N■N■a11 1 -_- °f sic,-,;a N M-■11.5 zU■\\■nI1Nf/■■■11■■r■■■1!■IMERM OO WARil\■lNFA■■■■ffl■■■MN RJR 'O °.■/■■■lIt7Y7La�r.■■f■■.:= W 140 N ■\4 r . -es ^ZG. r 11 • MFi!■N■NUN\N0 ■■rNU\!MN!!N■U■Nl NMNpU■fi■N■R!-Cu1>te7GaMUw9.MN■NNHR■N■ W W ■�■ \1! ROMMAMNP!2 !fGV■N/N■X/■M■■u■NMiHiin O = ■■1N/N■/1■NNNIN NMNMU!l Nt.II!7■N.U.NNMmiG/u/!N!N■NN.NIN■fNM. ■C U OM ONENESS MMMMM IRIAm!Aff Me tl ass MM.M!ismt■.CL ass NE CD z 935 CCCC■.. ZR■O.17r9L ■■■u■Hr■H■■E O 4 nom■rime° ■■R■■.S■■■R■R■■■R■■■!/■■R■R■.Nf■■■M/■R■■Rs\R■■■■■■ O RZIWI E MiHR_E\HGYI NRRfR■■■lf■RRR■■MMN■\\■MENNEMR:■!■■■■ONELER!'■■■!!!!1 ku N -mN■/f►ai/.- Si $ fNNf■■NON■■N■N■NflAeCGLAf■O■NsfgiAe�i/N■�_ as ■ ►�■s■!rm■AS∎n1 fsiIYS■■■e°iel R■■!■\!!■■■R■RH■R!!■\■lfrlR■■■/\Nrf■rs!■IRIM■f■R\\ Z. 130 mg I■■LR!°mi.■M■Miiee■ii - F fl■\\II I- \\l NII\!!!■■1!!l ffl/f■►iI■■\rlmGr00\!!\1■r\■■f■l 111l 1\/\\■1i/\\/!\1■■1\■f1■!/\!■\■!\■!!\t■!!!■1N■■!!\MN!■f■f�N■■■f\rNlf\1■■\■ W ■ \■■11 ■ MG■■■i °-------------- Ug ■■■/■ Z ■■N\■■r■\■\■■1■i2 I TAI MM■■■1\1■■N■■\\■■!\ff!\1Mss■1!lINROMI ■■■!■r\■■f1■!r\■f\■!l N1eN\!■■R■■R!■1!■rl■f\1■!f!w■a■f■■■/f1Nf■■■! 125 R\HEW■■MUUP lUUs - - J ne p r. I • iy ■!■1\■■■!■■7Y1H!!ff■■!fr■ff\1\■■1Nr\NNl f!\Y■/■ff\!■uf■/!\\f!\1■\■N1■■\\■MIERMC■MCCi■7CiiI i�\N!■uINR■■■■■■■■■ ONMM■!■R■ H/MRI. - I N■!■inl UN■l NNNNU■■!R\U■�NU\UUIU■uuurU■uM■MNU■uU.. !AMMON 1RUNN/MN/Nl■MIUI N■■MNNON■MME NUMUN■lfNfN■\!u■■!■..RN NMU■IU RNNNINONi=L.uuMMUMUaM!■u■uHRMSf\NMNf■N■M■N 120 = fii ...1._ NN� V ..--.i.`sGiRf!■R/!■\\!■\\■/\fr\■■RR ■\■\!■11/lw■■■\\■■■■■■■■r■■!■N■ -_ 1!\\■/■\■1■■1■■\■■■e.ae.■4� i WAWA•\..!\11!!111■\N \■!M■■■\■1■■■■\■NN11■/■ t° sows ■ ■■i•■N1NN\11M . Ali ■■R■N\NNMMNU\N/M 0 MM\1N\\■\\\■■!!■\\.� il!lU1NEWU■1■1MN■!■UN...HIMprNU1,Nl,■1NU\MU U !�® ~ .Na N ■N■O!:SB■�l■!\\■NNN■1O■MO!!MlllNNf11U1N11N1EWM1NNHNwH1■/1■M■MiNNIA�. 11■ C WNW �!°a ■■■■N1■■■■■■■■■■N■w■■■■■■■H■■■■■N■■H■ '.C7 0 V ■■\\\\■■■■■!\U�rSS■ „OHMS. - rNN\■MN\NNNlN..NMUl1\1■■■■UH!!N D .' LEGEND MMNNl11fwlNIM TAI !!!■■!!N\Nl■!■!u■!!fOMOOMMIMOMI ■!!NU!!!N!■MMOMMINMN■\NCRNR■UN Q Q o MUM .H■ ■■M\■■N\1■■..■1\111!\■1■■N■■MNN 500-YEAR FLOOD f �t~7 M■%111 ■■�: ■1\ —__ > t-2 MMN■NrrG RM■N\N1NNUIM ---- 100 FLOOD -z M. ■■RMl 1\1►w1■lff!\ll■fl 11■N■■■■■■■1■1■■■11■■■■11■■■1!\■■1■■■■■■EUENNE1■!\■lENNOMMENOSONM!!■11!11\1 W y \f■1N■lr.UEWNUUNNsMN■MM■■■11■N! — 50-YEAR FLOOD t7 yi . - 110 MOW; p]{ - - ¢ F.3 I : 10-YEAR FLOOD W i■■■■/C■■■U .n■■11.■■■\rl■11 M G1 Mit aII■■M\■N1■■uN■■UULIRN 1 11\.EW■NN■M1■ �'���%07� ;? STREAM.BED HEWS 1N!■HEWN..\1■f■/N■il■f111NN J • diems 1■■1N11 ■fl\II ■■\1■\\\■\\1/1r1■1\!!!!\!!\!■■II t\\■1■■■■■11■■fl Q ■1 1/.��N %i7P. CROSS SECTION ■■i■P•�t- 11/Y101��f(1 ,.wl!■MIUOi wilt\'\�!�11NN■■ m ON■EWN■lUi�/il^M2NlMU1\NIMNUNl1NUM■1O1RNMIN+ LOCATION w• Nl■NmNNNII\■fU\■i\■ir\1M ■■N1N!■\MU■■1■MNM\/N\ii u. � 105 1.0 1.2 ■ 1.4 1.6 1.8 2.0 2.2 2.4 2-6 2.8. 3.0 3.2 3.4 3.6 STREAM DISTANCE IN MILES ABOVE CONFLUENCE WITH TUALATIN RIVER 02P • • mmmmmHp„„MM ■nM aH/MMiM //!lMNa ■\N=N//!/=�a �� Na/1H!/N 11 moms �. anw;Ei (t • 'iiiim-- n/uluuiii/11niiiaiT/iiiiiiili/al�/HN/f•• M`iniiiiliiiTiiiiluln//unlN�� VI m/H/\Niia/pia/""//�iiHiCiis/MiMMIMMNNa°MMMOE°'//a///Hl//Hl nNN/!/l /N aa/MMMUMMHMMMEM asNUMuMMU///N!//MM MM///al/la/lNl MMMMla/!/ //////i=ii. aHUMMMMM. nU MMEMH EHaIUMU pull Ia....uu.la.MMU/HaaaUMNIIIHa/Ha•MMaalal MMUMaIaHM■ MM/HMMUOUNM/MMaall/Hull/N//N///l O.a/iiva HMMUMIaN JMN HIM//////HM.M/MN■MMMM■■MMMM/MMR!/laMaHMM ' // •lLi m...uuI MMmaUN .y Mluuuuuiiiiiiull/Hluuln�•MnuHM il.nN.U..IIMNH.UN/MU/NNMMlUlaMa1/Maa/NUr n It iiii 1Ma/MOMMINU II pp FFF • MUMS H.MHMI•.U..UM/a■" : ■MMMMI■/.MMNMMII/MMMIII.MMII\Mall\MM/MMMMM•M ■MuNala/a UMW 1 �■n MMMM/11N/ME sln ipi au IIMMH/MMMaH ■.Oau.MMMa ) r MHMEEHNMMMEMEM - NM ■MIIMU/ aUUU 1 NM III Tom /Hf iiiannMMU/MMMu- am y�■a11UNMUlfL'IUEUM/uUMMMH/nnN/NMMMNH/ r MMu . [i�■MII ■:lI :WI IS: N Hu.MMMHH\a.MIE. .I� EMUMMMNHEMMMMMMauaunNU/M/I;o .OU _ HMU a... EU M a4a °U•M/i NMI \a.aa Y MUMSMiMNUU/ MOON -�MMMMMI/IMMMI MMMM MMMar/ /a■at/uNMH.. ... C w aNUM/ uMN//u//a • N/NUM.i.i_ac7 MUM MMMMMMa/M _ H V /NHMMMMHMHMa///MMaHMaM/a//■M/MM\M/Ma!/M//M///a/■M\M/MMMMMMla/Ml/MaMaMMMaMMIaM/Ml\MIaMMIaM//1aMElllIMM■//MMMMEll■/Ml/a•�I......l 2. S50 U.,,. �Ma.. /aa••• calum.<'Ii7YUla// O sa:..r •eeacai5.m..=e o CM/MMMMaaif .ballMulU i!SE+/aa/aIN�MN/alnCONTMMUmnN LL U UMW ./Mna9Ma-i7nluHMAn/nMH/vl,eBC7egiraaNlM/lH/NMM CD ■ _ /aHMM[SMHM.MsuMMNMM4�[-i-iH .a �e r�■N//7iianM aaMM MM/MM/OMMOO M/MMMMM/�Ml\MIMMOONUMM/MIMMMMI/ _ .oU.MNgre==p!= IIv/(■MM �Ji/u./„ i j •'Oa=e-9=Ew- M/TPEO0MMMMMM\/DAr�M/MMMMOMMI IM //MCMMMMCO Z u '/!IC�C - - uks:aa\ v*raau. aUMaMau Z 5 r a = mom t NllMU/MH..U../AMuIS/MIIMHI/IUNM/uMNNNErMMMM/MHMMUmu•VI Y �, ... /i1%7a. �.aaM/g■ Gr it aMUN/i z Ms C M.. .IiMNPE DaCwMMCDmo mmmMMMMM/acMMMMMHMOMSMMMMMMMMMMMMMMMM/MM\MM!'JCJMMN/Ml/\Ml\MM/MMMI/IIIMMMMMMMMmana M/M�IIaMMMI//1/MnpiIMMMM 4 r.•J'Cia�aMl=saHEMMMUM/M/MMMNEMMUMMM/MMMM/MMMCC M MMEMIMaiM/MMMMMUl a W 140 - M U t� !N MMMM■ w OEMM000NMUMUMNUMIUMMMUMM 1 HMUUUUEMNNMN/ w =l4 EEM 111 II jai _ 'a iHMMMM/IMMMMMMMMMMa/MMMMMMMMMMMMM/aIMMEMMMM/M MMMM/MMMMMMMMMHaMnMMMM 1=CMMMMMMMMMMMMMSOMMMM/MMM MOO Mille MMMM/• MgMei�MMIM/ Mill/MOMEMOOMMMMMMMMMIIMMMMEMOM ME MM■MMMMOMMMEMOOMOONMIII/MMMOMMOSI MEMEneMEMMEMMMMEll/M MMMM/lafMOEa.:•I.OWNEMOOM/lilllllalME Wilt 135 bYa L .�/ .:.G >. g/h.1' U a e:ati:a3anunolunumulmMMH U i/°iulmM NW. to=M: s:ouu/ oaHM/Hn /IrIM w .L/MMMMNMEMM/MMMammi MMMMmd 1\///\Mull U /aMaal/NMMMMMMMMMMMMMMMHMMMMM/MMNMMEMM MUM M2MM MMMM/MMMMMMMMMMMMMMMPM / Q mNMauU/MNMNMMNHMNGMM .o,.•r/.®i WWII OIMMUMMMHIi1M.raM►'1 ii„iUMH/NMUI/NN/MnHMONaII•///d.HINIMA�I EMMEM �, i• is Z Q HMammuMI■MMEMMMM/MIM amm ' ' - mjilllammem MMMMMMMMMINMIaMm imumaMMM2MMmamma - • _ /HM.MNUU.U..MMaMMMImN A i OMB w C p t30 MEMIM1MM:iENMM/MMMMHM�oiMUM/MMMMHN /.V/MMMM/MMMaa uuaMMala/laaaHIMMN\UMM 0 a U raph LEGEND I Z MsNNNMMMMENauElla MMMMMMUMaIHMllIanMITEMMHIaMHMINTAaMUMMOMHMUHnnnnNanMHnan Q N mm............. ■ 500-YEAR FLOOD f waNHMIMM OOKEMMM UMMr NHaIaMM/MMMM►`:�HHIMMMNMMNMMEMMM/MMMMMMMMEI a MHal/laMMn/MMMMillanlananMU > t'z Ma 100-YEAR FLOOD v u.Y MMOONM/IMMEMM C/4$ MM//11MUHMUNNIUaIiM — 50-YEAR FLOOD ¢ f4 ■ ■ WE. 11 M/MM//Ma//M t25 HMauau ■aua\M■■aa=mmauE= MIGiJaammumummutlimnsoll 11 II 10-YEAR FLOOD a NM/MaaMME ■aNM/MHMUM/MMHNMMM MEW MHMM■/MHMIInUI IMMIMaII■■UUUU I aUMMMUIIIUMMMW MM w V NMMMMi i t:M■Mtl tirMMMnI MUUMUU F�SMS`%\TI STREAM BED ,.� • MO /a/ ■uuM■Mlln/NU t i • Q U[A1aMMMNIuMaMN/'w' - - MamIM IWIM41•MsriI11 CIMU� 41 MMMMMMER 11114111111641111111111111111111 U ■"f ill ■ ■M�� '■'11 ■ ��:�aMH,[.i /I� CRLOCATI TIOk !/ENNMMU/N\•.//\M/NUUMMNNiM►'MJI�M��� .UUUUIM►`P UaM`•UUUMUMM V LOCATION I 0 � ounMHIH/NNMEIi MaMH MU/ uMMMM/M� /Ea1EUUNIn 3.6 3.8 4.0 42 bA 4.6 4.6 4.8 5.0 5.2 5.4 . 5.6 5.8 6.0 STREAM DISTANCE IN MILES ABOVE CONFLUENCE WITH TUALATIN RIVER 03P • j f�' ■■pper� sef .ff .fmuegm I MffefN/pi fne.hiiii . Inutrniamm Mler nmH.M.MUaeMSqussfeMMMfMM.geMa■ II •,. A fsMMea li iiiiiiii"mummus iN iiifiiiiiieiiiiiim ■■ffefsa• 1 wwrMM�° eu MOM uMU ISM fMMMOgsuouMMUSUOSUgfgouuMMfoe I_I N.aan.N.M. e.aM ■� wemeeMfMMEMIZlMeA egeeMe efu..eM.M�e Mee.eM.qe Mee■Oieu eee qee Mqe M/e Me.fM.MMMasH.egMeugaeaNMMM.MOMMOO 1� M.e W aNaM 11 ee1611 i/a a... y- sMegi/3ssamel3■i. egMONSOOfauNffft / efel' i •••ff••••UU Mm.ole.gea.a �y asfa / .6 1■f W gNeeif#HNNM � euHeef.Uffeffffff /fe..UU.Ufefe■f •IReeeff eefffeeafesffefaffegffffa fffffaa .••effaf: a..... mmoommmimmommummr_m *Ji ;gm saMMK7eemM ■ A• IA* MmsI3gmfe[3 fgsM.gM.M.q �/aHlfsMa..M ,:saeeegsffgeMMSfeMae q usf..MagMfeseMaeefffsuM.MSeM.MM 11 .uNiaU u SUa u Feu . Meu.e.H..feuMMI M.u.HgMM1- aamHiASSSmeFA gegeMSMSeequffhleMSfsfMesMgM rl- sfafffMMMMMMMRE M WO gNgeMMMMSaaaN 3: ..Mm.sa.Ufeffeuse SEMasuHM.MgM/Mfuq.eua•MMUMq O S le 'ail Mmq■■MMfeMMMMI MNN..aUmua!aysfMfa M.eW _ RII/■■s i ti MU•' �. moms .;e: eeeee faeeeeefMMMMMM■.fasfsgesfefe/ease..ases.e.lfNMMMM MMMMM MMMf..a fgasu.gafafefe e.gagaefM4f.fafafss.ata. si 165.M �i M.N 1 U .aMeeam Le p Q i'.. a. MNfgf GIs. KM MMMMMMMOM•M.fMMq U•UUUU•M.MMM•.eegMH•M.Meffe•MSWW OON p ae.em a 5t/Mqe/eesasfe fsq.sasssee efseMMO MOOaaae.seaaee faesMM OM MM.aeaa.aee..ise.■a ae a.gsM MMMMMMVMfeeaeMaeeaseffa...aes 9 C Urn MUM aefeafel: efHMMMq.fe..Mafae sffesee/aff.■sfs.feeeeesffee.fesgffff.eeess MM ssseeesea.JS.ee gas....sse.eaee...sesafliea..a!_=2411 1 3 MUM.MMH_saUOSGai .L soa\i!s I aAgessMM.MMaafaaAP.. l=Laa.PBLn a I!. 0 1�■UUUUU �guiMmumzma .aafagaaa..memm aca:asfaGLMeea�sMAMMMMefeaeemM fee...eaemsMeeef.e.gaeesf fesMeeefefg.eefomg.fe.fe.eaeafsee ue.ala■f.aa■m7o E9Ta= _ U.. ,, w MeeaYa/Y.egHiMM•MTE Ml=7:G1...Mfe eiesesq=eeMeesM.M.us.e.ffMefe.M W i.aU u•UaUU•UUUUGi S=21..e.1111P5 i.44 ..0 UU.ee ofs■ZI UU.UU Ussefsf es•M■.Mieef.sase.eeeaaf.seee..eaei i. 0 MENNIMgeseeee..se.essee.sea.efeeaa.faeseee..efaaeMiffeeee eff■■ae.e.e s/.e MfeiiniuufffefffMffflfsf efMeaeeM.egseeOMMMMssea F U. > 155 - W •JU ii..Ud.. .U.U. ..e.e..e.asf U.UU.UUU sseeseUU UUUUfeeeff.UU•UUee.UUU.Use ./fefaf..aafe.a.f.fe mum. :Ammo • - ■ • /aas.f .eaafufaaeil ■■.....a.i/.f ma.fmM•000UUUUUaU UUU ■ .Gg°■ q. sffe es..m.!e:∎a.eoi'..∎iesfiief/i:g-%saaasasffeega.fffeemeeeeseesage/.■f.fffeeee■.eee.f.efffeaas.eegagaesmoggy 150 _ p>> •i efeaaMSSgfsq Z ∎ii- N Mffasasfsa.■effseffeefgs.saf.egaa.sAef.efe■eafgeseaHMNNMONM■fee fafg.fffeMMMNNMMMMMMefesaei...fefea W agMgasquMMe11MA= 4 �f s aM Ugquugfuqu.MS..M.Maessgfufauii .fq..f.se.N.s.fel--%� z . iis ffMSffaff:Neea%...\.e..\feiseasesMeff.ffgge.ff\feseeeee.sfs.ea\.eee.i ammo esefe.eef;�lfeef....\ae.Mls\ff.e.efff\feseef.s\.fsssasf 2 0_ . nis 145 N ••f.!5%qe 0 ®u a.M.U....fq W LEGEND ea��%feggsM.Maeee..eeeegMOMMO M/efefeeeagffeafe..aeeeee.feeeesasseeseeee.aefg.e.eeefefeefffiiiif. fr ...a. •■ 1 500-YEAR FLOOD 2 9 p MOMMMasgMaesu a.s.e■eesegeaffsaaafgfafs.ffffaffas.q > ~x • 100 FLOOD > W UMW MMM..atefaasesseeW essfeee see esseeeMeee se.fa.sseeeefeesfeeagsfaaaeefssegaBOO w. O a UM - 50•YEAR FLOOD s. 1!D agfM.sefageu H.MMeM.Mfu ffMeeMSU.gq.M.gMgefM■f.sgM.HgMMUeNaeMafuHasM.MS --_-- _ 10-YEAR'FLOOD Iii . N.M.ggu.NS slue■eeMe�eMgMffeuguuusllMMSS.MSeII � Cl HegeeeM.MH e� �,�Y■N u 1N1 NM WWN STREAM.BED . ' .ffeMaMMMesMI nsaNasfgMggq W■bM/1MfuMafgH -4 r .a.M.MMfa.a•` Ng CROSS SECTION w Mm Milli /� / i;e. 1 uqee HaggM..d.meme.MfegM.fa•.rc•..MemHgy- Mgafe LOCATION W 1 Me.ee...ofee.eMN.e■egsM.MgqqqHqqqMluaeI=eesMM� _ a 6.0 6.2 6.4 6.6 6.6 7.0 7.2 7.1 1 STREAM DISTANCE IN MILES ABOVE CONFLUENCE WITH TUALATIN RIVER 04P w wwwH UN / BACKWATER FROMFAN NOCmREEC u!. Iw wwweee1 NuNNoNu wgminN=/iNiNNiNiuf� u■N■Nt■u Nn tt t U.M Y wU■ mariniffe ZONE" iii'lUl Nee\_N ONE ANiti■ lulwNeleeMilel 1 NNee NUlwnUeleMMNe UNMMNMNnNNN MNNMMO W■■■M.M■e■. U i■■• w■ ne■ew■e mom= i� moms C w ■■■■N■■■■■■ ■eee■el■N non .NNMIUMU/■MUNU/e.MMMUutr.MM1eM • , MME:reN:MMMeMNU ■MMMnM\eNNeeelN■MOMSMM !1R■enU1 N)wleeene/leN/NeeeeNNnlNewlNNNeen/NNr.enNeneN e[dUi /NNFYUUUU/UNw .r�N000Nn Mewet3le ......■■■■■■■N t- ■UUUtIerau -/UMUCJMNMN1/■U■NNN r NNUUUU•UUuUUNwUNM WMMNNiM ueir��wttl%le1N// leen111�eNMUN1MMUeNIn t_i ■■ MMN MM wn 4.0 aIJMenMMM a i a■■.■■■■■N.■ UWi■SEM uooraeleeMneuuuleu ,i.I_UU nNtiie:.11 1 Iran:iLU1eNNMNe. on ... - ■ OH■N W lee • • •11■l M1■■N- i' yNe■■Mr. • ® uW+ solweio 'i-7e■n Ut. CC 175 NN■N C GGG ■■wN■UC\■N C N■llee • ieele.0 d Mw■■■■Plies■■N■NeN moMMMNNUNNUM eU■111/NUMnuMNUrMUnneINNMUN1Usm W. nwue Mew ■■ N ■■ ■■w■■let• ■elsee■eeeleM//eselMMels�ilMe/11reeMeeee■eeMeMM Ml ■/ee/ieMN■n■ u 170 wdah la W. NNl/en Mee UM i ■ i/le/eeeeeleUUUUUeel w NUrn■el Mil MO=UnuMUNeM1MUNMnNnEeunUwu/M1n1NNNUNNnuwnelwnpwnNMMMUMMUMMMMM/MMMUMeeMNNeeNNNNeeN/Nnn■nMN uwouN�i ■ SW 165 - ti > ■N w U■NN moss ■eNweleNe�nnMMeleeNeeNne u lUME1UMMUnnNMeNNNep1NNN■u II - ■M■■ ■■■N Me1MMO OMESM■MMMUMMESEMMe1UMUMMOOMOMl eel■e NMMMMM/■■■uMe■M■■/■e■e■1e/ee■eM/M1 ere/ee/1UMOMM IXMU■M/Mlle■MMMMMe■er■■e■■■Ml■■Mee■■r■■ii eeNe N■)renneel/Mee■ee::rlerrrinlNnNM__ -- pp> ■MP�s■ gp.pu.r.c�.7�P�7� _ S tO _ > 160■NM mum∎∎gr Naaom =aaaA�ppMnmaz - Neese/eU1UMl11/Nl: lee■Hell/Ne\/N ■■Nl■ooNU/e�rei�iNeienoIIiUt ■ w TWIFErN!PME5esseEer.■\■ne_ �e u ■MeU/er nMessomMNNNNM z nu11111/eMM/leeIUUMUMeeI■lee/e eMMMe1MUMM■ee■■e■■MMMM MMMM■MMMMMN■UMMMMMMeeeeeMMMO MMMMUM M/eMIMMMMMeMMMMMMM OOMeeeMMMMOMMMMMMMMMii w O— 155 WORM :�J MEMO w LEGEND < ee.M/1 Mele U/Mleeeee UMNU.eI.UIU Me ■ U11 M1e/ � M < Q leNUr■N■UU.R 5N■Ne■Ne■■UUUU!E -- 600-YEAR FLOOD f F Z. sNO1\1.111:1!.1:°s7/• U• ___ B■i� .M�._e i +.� M■MNMNMU/MMU1NeelNNelNNelU 700•YEAR FLOOQ Z o Z eeeBrr-a.M;.lioueeeoe°ri'isaaG _ le)111 50•VEARfL000 _w :50 — — +0.YEAR FLOOD w ■ w M111MME MBE ■e.NnMIUa %�����w/'���/� STREAM BED w 1/eUnMPiC\elMeeeUrleNNIMNMMIeeMeCOOS 1�e.• ee CROSSSECTICN w AN i r ■�:■eM LOCATION w MMMMM WS D.0 0.1 0.2 0.3 0.4 0.5 0.6 �{Ca STREAM DISTANCE IN MILES ABOVE CONFLUENCE WITH FANNO CREEK YJC gl EACKwA -itilat • 0 s �onunHmW\!Ms•mmumil�mHHUismm l....Iyl AIII1./isms°iilnan uumpuiniiiiiiummuuiniiiii° JC ■ M ... ■!•!■■ WW ia-iiiiiNdl iiiiiiiWii6HHSHHi■Aimsli........ iiiiiiiiiiiiimmummu !shims = isnHHH/HMMMM mum HHH•ii HwlW •!!■!w•! .::..U......A■::: ..h:riRUU••• UMW!■/•suss/•!!■!■!•//\WOW=IHH/■!■C 2 a a.OOOmmOMHMMOmOMEM Om::OOlOam Wm W4MOM mW:Omm Om u0WOROMMm000WWWWUWUWWUWWUWUWMPWsmOWU\wUWUWWWWlU W COMM MWl HH\UmHl uF4ml WWWrwWWWWW WWWWWUWW■■w•HUUUlWmmWUHWm!/UWUW\U/ a mWKlWKUHlUlWU! a mmmsmmammu WmWWH4imUUHlmWWUWHWC3/mUH\3!Al lmWmuWmummu m mummMMmmUmsmWU•HH!•W\lUUW■WmR� .1H■ummum •HH■HH■ • WNW/■/!!WH Nis /mml mmssusm!!•sm!!s/■■sl mmm!/■s/■■!\sl ss!/•asl ssssa•!\lc acA/■//s!!!!s/s/ssi•ssas r a ° :9H H•=•HH■HS■/HHruu/H■H WW WW 4eJSH/HIHH/HHHH• * {{{, !isms°iiWWW4 iIHH•HHH■HHHHHH..HHSHSIHHHIHIHHHSHF 1u ! oWWW ' W Y le?Wel m/W/Uw WWI MM■■MMMMMWOMMMM MOWS!m/WW WWWWWWWmsWWWWm l W MMOWEEWWWWOWCOMWW ass••ss aWl W■WWWU W W WWW\!!!■m•WWU•!m■mmm■m/msm Q L2 UHMMM mom UmmmH WWlu UmHHH UmWWW HmUWUmWWWUUWW WWW WWWW HWUUUUm uuupu■mpmuppuuuuWrmWHU\m■m\mOmm MC C W ME go i I 170 p w .■H�emr= =::. C y WWHm m WOW■WsammHWWHSmmWUWWHHHW■UWlWWWWm MMM MM ammo WUUW■WW/K■s■/HH/WlWWWH■W\!m\m■•-Fr a=aw•!\•m9!"E'= user GfRS-ii. W ma s suss °> m■mss■WWWSWWWWasemmemmoWlsmm■!mss•••smmWas■WmMMM MM s■W!■•MMM MMm■m!■WWWMMM MMMMMMMMM•s•■••MMMMMM•••\•\•siM M sss/!/■MMMMMMsss■!!W\z 0 165 wmmmluHmmammsmm mmm ummwstMMM m/■WW!l umW!/W!s!!!WW■WW\■mmsWmism■r!!semiWW uummimmilimWt/ ■Wre�r_cG:w4Wr•■lmmammu eMMMMMWW\■\ ■■ se. Lit •/••■!WOONMMMMM MMMMEMMOis/lsmmmmmWMMMMMMMSOME!■m:uWWOMMMMMWWWWMMMMMnWmmemm muss/lu■.5:.ma :•S./s•!•!•!•/\■f!/0MMMM■WNMMMM!••/ ^a! isl. m - :•\% me omitoramo .UUu Mommom/.mmW..!!MMMMMP: sWWmm emmosWWS•masssmWW�W ommisom sass■Wams.t^:..s_ie==smaissimmea s/...- /mlWW w w•ssn•r:agammcr: =% lsmWmmWmmm MMmMM WSl mmWalmWWWmsssummiKe:ra/HSSSI•.mi/ssa•s•K•U..... ,y _ :Vemm: •eCO r /WOOS lACWMWMAMO !II �s_tlV SiLi■PAWHU!■Hl\!!UlHHUWMOlHK■mm! � imm,/■WHSWHHWHWHO 'Pr.••4 ee..,M MMMMMM;iIHUH.HUI■W!/U■KUUUumWMm m- - ��. m/MHOS! i-.GSoissivs as∎si. - ■ > 155`° - U\HU.S' Osesse■!!■ss/•■!••!•••■■■/■!■!•!!!•■/■•••■■!■OMWWWW OMMEW M/!■msmMWMMMf;.a./rml..U.•U■•a/WOW■•mm■W\mW/H\•W!\■u•!\•••U■•!W/m•■UU• !■•!■!!■■•■■/■•//WC7mms■WOWM MMMMMMUMMMMM•W■s■/Wm■W■•MM•!!•� i.. Jmm!!H■WW/MMMmimmgemme mss■!mWamWmmWH/mm/•mmommum.■■WS•!! C, WWWSWWWm WWWWmmWWWWOM MOW NEMMOMM W!■WWassume•s••/••aa.MMMMWimilt N immMMMMMsmm •• < •■!!•H\!■■/•■mMMMM■MMMM mum!!■■Wm\m/W!lr.e5:.•Ws!/mMimmss■m!m /mm Mmes osi mmrsiumWm ummoWWSrmsesimmWIli.7e:a'esWWWWWHWWW/.e, r 1111,4 SO4 41 1 I SO UWWHWmm■WWWU•WW MMMMMHUlmsPi•mW!•WWWm\HMMMMMMW MMMMMI m\l HOW■/`!!WWlUWHlHWWWHm■•UWMM S!MM J! inn. W Q.� 150...MOssss.mU..mMM..iammmm...•uKW%- .HH.WHU. w •0 .i mH!•r•H■.u....r\..U■WWWWU■•UU/a•/OW 10 0 U MmesaUuuus••ausauuasa!momem !m!•.mauWa uuuU amUumH•!•auauuu•!•H!!u!\Wm.W■mimmUmmmmmiWWUuhIW LEGEND I- i < 0r 500-YEAR FLOOD f F0 minim/!!m=a Immmm■!•mmmm//mH■W■•r•mlma ---- 100-YEARFLOOD i O= .. -i /m HWWimWWWWWWWWW!■!!■mMMOMMO•■WW/■■MMW mss lWmUMMMMMMm//!mmMMMMMMMMMMMM/WH W\•/ — W 115 _ •W\H/■Wm•!l WWH■H!HlHHHUWHHHHUWHHKmuUWHWmMMmumu■■■m•mmmuummuumu „ 50-YEARFLOOD 0 >�ce um mum - 10-YEAR FLOOD ' mmlmWWWWUW/HS•uWUWUWmWUWm mmmmmmmmmOOmOmoOmO a%OWSmUUHlW/H•/Um KiFN9 STREAM BED 5 UUWUU•UUVis f < i�\.� f��Ue fTiIIUWU■HUmWHHlW!■ /^� CROSS SECTION Q i! ,i mH V W . itIUmHH•W•HH■HW LOCATION 0 u. 0.0 0.1 0.2 03 0.1 0.5 0.6 03 0.8 0.9 1.0 .1.1 1.2 1.3 STREAM DISTANCE IN MILESABOVECONFLUENCEWITHFANNOCREEK 06P I • • ow ..N N _ ...Ul... ���- - N.u.tlt...u..U..UtNlUN.ttU nN..NOOnu..nNNt r�.f�Gonatuo/GunuNOal.nNt/ ..r /n..M..n...n.....l.M.N. f/. NUN.\NU .. U.OU.,.N.N. ■t.r....t..t..r............tt...tal.a...t....t..■t.l.N.l............lt\./\l N......s...ttt.l.t...t.2.s.#........\.. I Y _ ..H .U...N.../u.u...NN...000.NUN. t .N/tl is..N.UNiN.nl.nN....tt rsl .. /sN.\.f.NNr.sl.r...... umMMMM • U. r a .0 U nit I9 • ...# Urn I �.6i . L MOM....U.r. .. a mm .NN.0 - .'Rl..N.s ..Car...UU.#.MOM: tH • a. W � . .N.r..N\sN....r/..N......N..ss....N.•UI 6 W • fg. O O se . ••MGM.......■.....fl...f...r t.......1.....t.t.1.t.1/.r...t...l...t...MMn s..nN.rlalt.afu.anrtirr.N.nt.NtN W i.nu\N....u...000U..U.USUN.UUSnuNUUNN. .0 _• CS X .......e. a 1.1N...17 O .n...N...N......N\.nUNNnr....#i.f. `` CD a # N.t.#.lN■U......■f.uU#.s.uNUS/.l.US/.000UU�fuua ...■..1N Ul...U.Utuu t.U.N■NNaN..N.r U.U■uN.n.....N..NU.N#...N...■..:l.f..UUI. - rR.r/..NNf ,� Y uss../MMM...•Uuuu ..l t.t.............a...t......f........#\/l...r..a..■....a.l.....l.a....l.a...ra/r#/ 0.600000000110000m:..l.....1. ��....... ! /i .U.N.N ... .Oa. W 176:. 1 .........■■N .. ...t.s tH.#lt\.s.iH../...■..f.....#N\l.N■.t....ls.s..\s g iN.NUUZ.o.Pgma--z--z i_ Ia ..aUar 1 r.e=w -aw eaaaaM onNNNav pl�i.Reeeea_s=mrzzaza: W 170 s l.f. '� a_a:ii...\/N.0 N/.■U U...u...UN.UNNU UU..ru.ruuNUN.\NU#.UUN/.#.N\U ..N W A .........N/...N...s......U.■.......N\........N ■\UUN..■utt/NUOr.U2RJ , , Aa.u••N.iU.....NNa.\NUUn.N.N.nNa.u.NN.rra.N.\NNmum N• .l.■/.U..#.U...U.N,UNUU.s AsP./.NN....rl.Nl n.u...UUtt U.N.......NUn.aNfNit.f./nuNNiiiiN•NNNUa mulls II _ _ x. r 11 W , C.tN.n t.a.la...NUIlI..Ut.....N.s..sNN < _v BAND1114 .s/...\t..l..s.■t...l....N.../.■l...tl■...t\...st/1ss.N.s...#!. I.... mlss...irNttli.UU UUUU..\st..ltt...■t.....)rA.....\11t1.1...11../...al\s..l..tl/r. .u. U.000U..N:...t.l..r\..■ 2 0— 160 II dry• Wm LEGEND Z ■sl is n/11/..■1l.U..ls tt.l t..tt..al t/.l..U.tl.t/..tt./a!/ltl./.l...tt..�U...stMOMMAM..t.at..IUU. 'i • ` r u..NN■ —— 800•YEAR FLOOD f 1 2 1 C 1 — 100-YEAR FLOOD =. 0 i u..r. - 50-YEAR FLOOD i •',. 165• - w C =..O.N U...�� ------- 10•YEAR FLOOD U p MMMMM 1 .U. s .....l.. ltt\./11.s/a.rt: STREAM BED W :...lt./.../.r/.l...tl.!\.tl...t.....s....' 1./.0 .. ...s.....\l.l...ars#.. CROSS SECTION c UUnUmilmums.N.`�JU.. r�/NUS.NN.tU■ ••/ LOCATION o LL 1-3 1.4 1.5 1.6 1.7 II 1.9 i STREAM DISTANCE IN MILES ABOV E I ONFLUENCE WITH FANNO CREEK ®" r. /- . . Department of Environmental Quality 1.4._ 522 SOUTHWEST 51 AVE. PORTLAND, OREGON VICTOR ATIYEH MAILING ADDRESS_ P.0. SOX 1760, PORTLAND, OREGON 97207 GOVc RNOR August 26, 1981 • Elizabeth Ann Newton Assistant Planner City of Tigard P.O. Box 23397 Tigard, OR 97223 Dear Ms. Newton: I have had an opportunity to review the proposed wording of the City of Tigard Zoning Code relative to compliance with the DEO noise standards. The proposed wording appears adequate to comply with DEQ standards and Statewide Planning Goal 6 implementation measure requirements. I appreciate the chance to review this implementation language and look forward to providing any other necessary input during the planning process. Sincerely, U(1 Maggie Conley Land Use Coordinator MC:j M3118 Ea O'DONNLL, RHOADES, GERBER DATE: October 7, 1981 ,SL)LLINAN & RAMIS ATTORNEYS AT LAW TO: Elizabeth Ann Newton, Assistant ,4727 N,W. HOYT STREET Planner PORTLAND, OREGON 97209 (503) 222-4402 FROM: Corinne C. Sherton RE: Environmental Standards Provision to be Added to the City 's Industrial Zone Districts The wording proposed for the new environmental stan- dards subsection of the "Additional Requirements" section of , the City' s M2, M3 and M4 (industrial) zone districts, as set out in your August 20, 1981 letter to Maggie Conley, meets the requirements of Statewide Planning Goal 6. (Air, Water and Land Resources Quality) I have attached to this memo a copy of your August 20th letter and attachments, as you requested. • { CI111OF1I( A RD WASHINGTON COUNTY,OREGON August 20, 1981 Maggie Conley Land Use Coordinator Department of Environmental Quality 522 S.W. 5th Ave. Box 1760 Portland, Oregon 97207 Dear Ms. Conley: Enclosed is proposed wording roar the City of Tigard Zoning Code relative to compliance with DEQ noise standards. This section will be inserted into the industrial zone sections (M2, M3 and M4) as an "Additional Requirement". I have attached copies of the "Additional Requirements" section of each chapter of the code where this section will appear. The proposed wording for noise compliance is as follows: "All uses in an (M3) (Ma) (M2) zone shall comply with environmental standards as adopted by the State of Oregon Department of Environmental Quality for air, land, noise and water.. If it is deemed necessary by the Planning Director or his agent, evidence of compliance with DEQ standards for air, land)noise or water may be - required. Evidence shall be in the form of a letter or copy of a permit from the regulatory agency." I would appreciate any comments or concerns you have on this as soon as possible. The Planning Commission and City Council will be re- . viewing this item in September. 1 Sincerely, ei odh 44441 /le/Vila'? Eliabeth Ann Newton Assistant Planner EAN:dmj • 12420 S.W. MAIN P.O. BOX 23397 TIGARD, ORF.GON 97223 PH: 639-4171 18.4 4.0 50-- -18.48.010 a rear yard setback of forty feet shall be required; (4) Setbacks are not required when side or rear prop- erty lines abut a railroad right-of-way. (Ord. 70-32 5160--4,, 1970) . 18.44.050 Buildin. height. Except as otherwise provided in Section 8 . . 10, no' •uzl•ing in the 11--2 zone shall exceed a height of three stories or thirty-five feet whichever is less . (Ord. 70-32 S160-5, 1970) . 18. 44.060 Additional reauirements. Additional require- ments applicable to the M-2 zone include but are not limited _ to the following: (1) Off-street parking and loading, see Chapter 18.60; (2) Access and egress, see Chapter 18 .64 ; (3) Enclosure and screening required, see Section 18- .12.080; (4) Signs, advertising signs and sign structures shall be subject to the conditions, limitations , prohibitions and requirements of Title 16, to which particular reference is made; (6) Nuisances prohibited, see Section 18.12 .070. (Ord. 78-32 (part) , 1978; Ord. 71-4 §7 (part) , 1971; Ord. 70-32 §160`-6, 1970) . O. ) Old Ifif0Y1 IWAtifaP 54-andr-dc Chapter 18 .48 LIGHT INDUSTRIAL ZONE (M-3) * Sections: 18.48.010 Permitted uses. 18.48.020 Conditional uses . 18.48.030 Lot requirements. 18.48.040 Setback requirements. 18.48.050 Building height. 18.48.060 Additional requirements. 18.48 010 Permitted uses . No building structures or land shall be used, and no building or structure shall here- after be erected, enlarged or altered in the M-3 zone, except for the following uses: ( 1) Assembly of electrical appliances, electronic in- struments and devices, radios , phonographs, television, in- cluding the manufacture of small parts only; * For sign regulations, see Chapters 16 . 36 and 16 .40 of this code_ • • 279 (Tigard 7/15/78) 18.52.090 landscaping plan, waste disposal fields and other construc- tion features on the property; and all buildings, streets, alleys, highways, streams and other topographical features outside of the property for one hundred feet from all prop- erty lines; (2) A description of the industrial operations pro- posed in sufficient detail to indicate the effects of those operations in producing traffic congestion, noise, toxic or noxious matter, vibrations , odors, heat, glare, air pollution, wastes and other objectionable effects; (3) Engineering and architectural plans for the treatment and disposal of sewage and industrial wastes and any on-site disposal of wastes; (4) Engineering and architectural plans for handling of any excess traffic congestion, noise , glare, air pollu- tion, fire hazard or safety hazard (5) Designation of the fuel proposed to be used and any necessary architectural and engineering plans for con trolling smoke or particulate matter; (6) The proposed number of shifts to be worked and the maximum number of employees on each shift. (b) If found necessary and upon request of the city, information sufficient to determine the degree of compliance with the standards of this title shall be furnished by the industry. Such request may include a requirement for con- tinuous records of operations likely to violate the standards , for periodic checks to assure maintenance of standards, or for special surveys in the event it appears a violation is in progress. (Ord. 70-32 5180-8, 1970) . 18. 52.090 Additional requirements. Additional require- ments applicable_ to the M-4 zone include but are not limited to the following: (1) Off-street parking and loading, see Chapter 18.60 ; (2) Access and egress, see Chapter 18. 64;. (3) Enclosure and screening required, see Section 18- .12.08 0; (4) Signs , . advertising signs and sign structures shall be subject to the conditions, limitations , prohibitions and requirements of Title 16, to which particular reference is made; (6) Nuisances prohibited, see Section. 18_ 12.070 . (Ord. 78-32 (part) , 1978; Ord. 71-4 57 (part) , 1971; Ord. 70-32 5180-9, 1970) . (7) (add , ►v,ONWlenia, A,oddrols 56 'aa • 18 . 48. 030-18.48 .060 (7) Railroad right-of-way; (8) Any business, service, processing, storage or dis- play essential or incidental to any permitted use in the M-3 zone and not conducted entirely within an enclosed building; (9) Garden supply store when in conjunction with a landscape contractor's office. (Ord. 76-46 §4 (part) , 1976; Ord. 70-32 §170-2, 1970) . 18. 48 .030 Lot requirements. In the M-3 zone the lot requirements shall be as follows : (1) The minimum lot area shall be six thousand square feet. (2) The minimum lot width shall be sixty feet. (3) No maximum lot coverage shall be required. (Ord. 70-32 5170-3 , 1970) . 18.48.040 Setback requirements. .Except as may other- wise be provided in Section 18.12. 100 , the setbacks for non- residential uses in the M-3 zone shall be as follows: (1) The front yard setback shall be thirty feet. (2) The side yard setback shall be twenty feet, except when abutting or across the street from a residential zone, a side yard of forty feet shall be required. (3) The rear yard setback shall be twenty feet, except . when abutting or across the street from a residential zone, a rear yard setback of forty feet shall be required. (4) Setbacks are not required when side or rear prop- erty lines abut a railroad right-of-way. (Ord. 70-32 §170--4, 1970) . 18. 48.050 Building height. Except as otherwise pro- vided in Section 18.12. 110, no building in the M-3 zone shall exceed a height of three stories or thirty-five feet which- ever is less . (Ord. 70-32 S170-5, 1970) . 18.48.060 Additional requirements. Additional require- ments applicable to the M-3 zone include but are not limited to the following: (1) Off-street parking and loading, see Chapter 18 .60 ; (2) Access and egress , see Chapter 18.64; (3) Enclosure and screening required, see Section 18- .12 .080; (4) Signs, advertising signs and sign structures shall be subject to the conditions , limitations, prohibitions and requirements of T r Title 16 , to which particular reference is made; (6) Nuisances prohibited, see Section 18.12 .070. (Ord. 78-32 (part) , 1978; Ord. 71-4 §7 (part) , 1971; Ord. 70-32 §170-6, 1970) . C7) odd el/L. vim j 41da )s 5C-06°01) • 281 (Tigard 7/15/78)