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HomeMy WebLinkAbout84-45B GENERAL PLAN AMENDMENT 2 OF 21I n In Chico' Not a77 2,i+3 ? da-41 trips would enter,'Chi.co via iii hwa north or south or y , some would head High+gray gg. if as mash .. s t.wo-thirds of proJo-ot traffic were to enter Chico. as p=�tianed e_rlier c congest, would riot be l;,i;ely unless several Large developments, were also auiJ4. at � . �, ntlrzd aFke same t' time, in which .ase entering mlico, by road, oo bid become congested at peak hotzes. Highway 32, eazt of Hs hwa about Sru-,e Road, is e� pea Yed tcy have a Le r � y 9� to vel o� Service by the year 2000. Leve. ; r,eL'"lects occasional cotrgestion and. i,s as trrc�,� l +. y ,•used in urban desi n t Traffic Bond=' �; � swandards. _`-ons whi-; h ey:ceed C 1 evels of znruice, that is � d x, levels, are an considered s gzrificant 'i tpac us. (R'afere rce Chi o Area Land ase Plan QIP., 'Apri1 1982, pages 1? 2_122. :litigatio*t • deft t:irlB channelita:ti.on, a land in avthe downhill (westbound, lane Of j2 tis rratnra�ate project reside?�ws and. prevent other traffic �rfrim .paving to stop. �w"rans letter of March, 12, 19$2. ) 2. Any grading for left turn or other improVPzen4,8 or Highway 32 should be revegetated proaa t tr y wish zrat vs vegetatian Prior t March);, o winter rainy season ' November to 3. the developer has considered incorporating the following measures into the pro eot design: Pl-ovid,e auxilsar t y pc a rens U the preJett without creating �arrcua traffic in nearb ne3 y .ghborhoodsx several local •ands waY.z d be u trap, Figure 3) `eat herrvey}sab� a; Cyurr,. Ctanptard { rked oz. project ,p�'aciecF to all-�� t gate at, project boundaries to be for e. ) �d provided with a s mergend use only; (b) to rediv:e overall trip generation~ the o r. �♦f Y �' Y �' 'S - - - P- d Provide a' co; venion�ce si+upping d gas station near raect 6.ntrance .see IN-C area on Project ?dap, Figure �); and (c) to reduce tri the generatic•n, the d"ve oper would r p Provide a stall transit µ y VrGi3l.�1.'4 b1Ak7 kr'm, the )project t arir van to cir elate through � d tie arx wit h 01. ' Schedule o the Butte County Transit System, bar deposit-, 3.iig crxtd CC6.s.1Cc^,ts,.�' �c�5+'"iehg�.''2".s c�'t eii�,�sVil"d �jl�'"c County r+ �+ eM stops. �y yY g Butt- County Y. ansit .ard Chico Area transit she fire station is to be 'build 'y umtjwr 19$2. li-ming Of the neighborhood womr grcial area is de e Srt ori ha�33 r9{, y yy�� 1��Yy I1 yY� r � y g u` uffx,'iOn - Au Aa ber8 o r e ai.4'c_r,, ii..i '�L,v 'Y, and the plans o� �F . leo .-ia�' y. ,4ustify it w projec, for a possible store and gas station neaa `ighwy and Santos tray; A. Community Services District is Wised to ad�rinistrate the transit van, and sii�ii�r fa?�trsrs ,p' fire station,,' beyond the ,scopeof a Homeo't hers Association, J. PUBLIC'SERYICES IMPACT The chief public services needed by project residents would be fire and police protection and school facilities. For each of these services, the project's demandmould not in itself overextend the. -iapacities of serving agencies, but would be part of a cumulative demand which; in the case, of fire and police protection, would resctlt in ' inadequate service levels ,and a need for mitigation provided by the projee;t. Fire Protection As human activity increases in the chaparral v:ildland areas, both fire hazard (already high to extreme,) ,end` the need for fire protection will increase. According to the Butte > County Fire DepartMent, the 385 unit development .would have an estimated population of 777 'people generating 8=1 medical aid calls, 2,8 structural !firs calls, 4.8 vegetation. fire calls, and 3.3 miscellaneous P.alls for a. total of -� ;year. These calls would' generate 'an additional 14.2 fire/emergencyMedical calls each annual workload of 149 rnanhours, adding' to the cumulative manpower and response time, problem created by the existing or planned developments in the surrounding area. The project would provide a volunteer fire department, to be located east of the, vineyard on the mutual water company land. A fire truck already purchased and additional equipment fought in the future will supplement the existing fire departments, enabling a faster response time. Water for the Doe Mill Ridge fire trucks would be supplied from wells and from the irrigation pond on site. This fire equipment ,would be made available to residents on adjoining lands, since the volunteer fire department and equipment would become part of the County Fire Department. With the fire trucks located onsite, response time to fires on the site would be much improved over, present and projected service levels available from existing fire departments (Butte County, U-8. Forest Serviee). '.gaticns» if the 'County Fire Department finds fire protection to be inadequate for the project even with the onsite ego[Ornent, its requirement of fire hydrants for developments with densities of one to five acrevflatt would be applied. Tach hydrah,t must have a min mill flow of 500 gals. mind. must _ 'adjacent hydrants;' A st bL soared a mi n►mum of 800 feet from ad' and have a four inch retain hook-up. For safe circulation during fiire!toseue orncrgwicies the Land Development Section of the public Works q re Dc artment uires: p i police service ,where it already inadequate. Significant unmet demand Will occur if the 4 surrounding areas are also developed. Ydflgatlons: The developer plan- to provider a security officer patrol for the project, to be rid, for througha hn;ncowners' ,association, in the manner of a special assessment d.,:trict. This measure (also suggested by the Sherif f's Department) would provide regular patrol in the proieeas well ast ' good response time to cells. A possible further improvement 'in security ��,rould be fo tie in a security alarm system with the cable television tine the developer .is considering instaWnn on site. This measure, SUooested y G the developer, would .enable residents to "register calls for emergency aid (police, fire, ti medical) rapidly with the project security patrol (or proposed volunteer fire department), and mould further raise the level of police protection in the project: Schools grades K-12) in the. Chico Since capacity roiv exist s for 830-930 school-a a children (a. k Schools, and the.: Bidwell li'eights project would add approximately 1p0 children. (at 0.5 oject alone would not strain or exceed the schools' children per household), this Y pr p y t eaparities. However, this project's addition, if accompanied b those of other large residenial projects either existing or proposed, may result in, overcrowding of one or t more of the schools. ;:i'itiga.tion,: r Y �h l` schOol cites, ,. � ^r o� eratzoe effort on the E. anawon unrls for uildin a newcss.,h of e�.nan ion of. ron tv part of the ­Md/or btiaZn oy studen' a a;,.rit coxae x a i _ ;;tribt. ` #„s. 7.i�Ze4� 5chpol '� d,e�ve`IOperaa project reamsdents and cititens of � _ e Ci11Co U�ii ill K. UTILITIES TNIPA eeded b the c oject would be telephone se: vrre; electricity, n Y P y The flu des swage disposal5ystem ma ntenanee. vxtural bas would not be>suppliied water supply g g til e _ pp their &Jh fuel from one of the b the utility, -those residents desiring as would sup ly local bottle! gas companies- Telephone ompanies.TelenTele hon p ` ti to sere th e Com any foresees no problems in abilrt;C e project from the lines they maintain along. H�bhway i� l etermihatibb of 'telephone line locati�ins within tare project and financial arrahorements bet peen the Telephont�k Company' and the p i costs would take 'elect after the development plar►s devela er for overzn� ns.allation } are firm and the detailed s�ubdiVison maps have been prepared. k . ,1. Maximum street grade on graveled and oiled roads should not exceed 15 percent,, otherwise they must be paved. 2. Bridges must be a minimum of 20 feet wide and have the capacity to carry a 20= ton fire truck.. The only bridge on the site is at least 20 -feet wide and can carry Up to 50 tons. 3. Curve .sharpness in a road must have a minimum 400 -foot 'center line radius within a subdivision. 4, lViulti le access _ � ;re lilted because snore than 20 are proposed for the p qlots, subdivision; at present there is only one access route. 5. Cul de sacs, because the project is out of the urban area; may be of any length. but may only have 20 lots developed within them. A 504o, pt -radius turning 'tele is needed to accommodate fire engines. When plan details arecomplete, this requirement must be met. 6. Road names and building numbers must be, clearly identified from the road and, names must be approved by the County Street Name Coordinator. At time of e:onstrurtion this requirement will be met., fire department includes following: For fire prevention and structural safety, the the requirements/recommendations, which could become conditions applied to home builders at time o,f construction: a. A one-half inch spark arresting mesh screen be installed on chimneys for p d woodburning stoves fireplaces an g ed of fire resistant ct b,, 'Roofing,tind tiding materials should be constructed Materials. ' � p development need to e. California. law ;s specifies that all wildland areas with de p clear all flammable vegetation ,for 30 feet around all structures. IIoWever, If erosion might create problems, some natural vegetation may be left in place but grass must be mowed and all dead limbs ftiom tree trunks and down material on the ground "must be cleared: d Fuel breaks are recommended along the edge$ of prorosed develc'pments., width will vary with the type of vegetation presentand , steepness of slope. police Protection Si'nce thwre ' s to assigned Sheriffs patrol in the project area and no future plan Cor ` increasing lav c -►force meat 'there, 'the development will create an increased demand for 1 Electricity Pacific Gas anti^ Eiectric Company (P G sic E) would have the eapacity`to supply electricity to the project using the existing PoWerline on site. Their requirement include nderm1unding of utilities with a s rsingle-family dwelling on a parcel less than I three acres in size. This would apply to the parcels to be zoned: SR -2, to any other parcels with potential for future subdivision to below three -acre Parcels; and to the 40- E acreP arcels to be zoned PA -C with multiple units. Power may have to be undergrounded from the supply line: to the clusters, as well as Within the clusters. However, these arrangements would be made in discussions between the developer and P f; k & E s New Building Representative after firm, detailed subdivn,ion maps are com let_. Althoua c complet'.'. bh no additional requirements are apparent under 'County zoning regulations, any such local A ordinances would have to be checked at the Lime of discussions with p G& E, as County requirements supersede those of P G & E. y A concern for availability of power, especially in the summer months ofI peak. demand, has resulted- in a policy set by the California Public Utilities Commission t (CPU. C) that the developer .ratherthan the ratepayer should bear the cost of supplying power at the initial stages of development planning. The developer must have a letter from P G & E stating that financial arrangements have been made to pay for the power. These arrangemen's would be made after subdivision maps are complete: This .CPUC_ - Po Y g supply - , Policy on develop_ir financing of ower su ly reflect, the cumulative nature of the impacts of dev„ loprrrnR.nL proposals on availability of power supply: While 'the Bidwell. ell Heights project alone ct+gold not strain the utility, it is Part of the projected demand k Which together represent considerable allocation of resb4rces for the Northern. Sacramento NIalley. i A Ml' TGAI'Ib1V,;' A tern moot set adk Frosts the centerline o ethe power Pirie is to be nforced for cwellilig units and we118. Water Supply a Water would be supplied to all Project residences through the mutual. water company, Buzz Tail l�'ater, Works, whose service area boundaries coincide at present P yi _ with Property ` p , and whr.rh note operates the two wells on site. More theincluded m this report, Wells would be developed by the coater company as needed, All v; ells cv h ould be part o£ an entire 'interWconiieeted system throctg out the property. All residences would be served 1 bya piped water system, with no individual Wells, The developer would provido pipets to ► the Rots: and. each homeoWner would pay a fee to 'hook up to the main pipes: i t u )+1 Water supply should be more than adequate for the development as proposed, At about 625 gal/day* consumption, 385 residences would need 240,625 gal/day; the existing large well. can supply 225 gal/min. or about 324,000 gal/day, more than the supply needed for domestic consumption. The excess supply in this and other wells would ;be available for fire protection. Cu=en: mower storage capaca,tty is an esair at,ed, 34, I'F'a gallons. The quality of the water in the existing wells meets all standards ,for potable water supply. Results of tests done by isrionarch Labs of Chico (see ?appendix l) are on file with ethe State Corporation Commissioner and the County Health Department. Sewage Disposal Project residents would be responsible for proper sewage disposal in the individual or combu lleO septic p ' tank-1 each field systems through a Sewage Disposal Maintenance District, This District is a means proposed by the developer to ensure that sewage disposal in the septage areas identified as acceptable by the County Health Department ent would continue 'to operate in a manner acceptable to the Health Department. Under terms of the. District agreement, the Health Department :would- be able to inspect., the septic tanks and leach lines' periodically, notifying, homeowners or Ori PA-0:areas) Homeowners' Associations of- any malfunction or improper condition) and have IR corrected at the owner's expense if they did not correct it within an agreed-upon time period: Thusthrough initial approval of septage areas before development and on-going authority to monitor and make repairs, the disposal of project seti'age should be done in a prevents environmental contamination and health hazard (see also the section n Water quality/Pt Health Impacts), L. ENERGY Residential use o` this site is likely to result in the following energy impacts: Assuming a maximum buildout of 385' homes ` es usirsg electric heat (without any offset for likely solar installations) the worst ease for nledtr-Id consumption will be a total of r5.8 million 'kilo viatt-hou►s per year. Gasoline consumption for commuting (assuming r trip ends per residence, tett m les per trip end, and 25 miles pec gallon per vehicle) will total 3931170 gallons per year: Typical water usage bre metered residential customer in Chico (.18750 al/mon hI ' resident divided by,30 da'ysrm,onth) rlohc Grant, California mater Service Cothpany, =43- 'Mitigation would include extra building, insulation use of solar energy for Mitigation rneasai•cs establishment of a small commuter bus run between the prooject and Gtthe heating, and Butte County , Transit terminals in Chico. Ideall.)) 2n i; z aa1 sul d� via Designs ,ero�'ci ' o o :r yess�'ve solar access` criweria sxiecifed in Section 66473.1 h ,. YL EFFECTS FOUND NOT TU HE sIGNIITICANT The following project effects upon the physical and urban environments .have been evaluated as ins bgimficant. This Means that adverse impacts would not be of such intensity or magnitude that substantial mitigation would be required. to bring them to an acceptable level; however, in certain areas some mitigation measures'have been. recommended simply for preventative maintenance of low impact levels, especially in view of potrn.tial for adverse cumulative impacts; Effects Not SigiWicant ` 1. Noise, exposure or noise generation. 2. Disturbance or destruction of Cultural Resources. S. Water Quality degradations w a Pollution of surface waters by urban runoff. b Pollution of groundwater or soil from inadequate soils for septage. 4, hydrology, Alterations in drainage, patterns.. a y b iricreasQs in runoff quantity due to imperviou surfaces. 5. Traffic Volumes on local. roads, Highway 32 (With the exce'pttori of the Satitos 1a intersection) and Within. Chieo. 6. Soil erosionrstreatt iltat.ion.. 7. Lrterease in service load on schools. B. Increase in service load on power and telephone 4,sterns'impsct on ability to serve. tl �4- V11. SIGNIFICANT ENVIR.O'NINIENTAL EFFECTS WHICH CANNOT BE AVOIDED IF PROPOSAL IS IMPLEMENTED The following adverse impacts would be reduced in severity by mitigating measures as listed within each impact area (Chapter IV), but could not be eliminated. Thus 'these impactwould still occur, even if at an insignificant level. Unavoidable Adverse 1. Exposure to seismic hazard. 2 Contribution to air polYution* 3. Alteration of *natural Scenic vieWS. 4. Removal of native vegetation. 5. Wildlife habitat reduction. 6 Traffic increases at Santos Way and Highway 32, 7 Increased fire danger and exposure to fire hazard. 8. increase in service load on fire and police agencies. P 9. Eae gy use by homes and commuting vehicles (contribution to long�terrri N depletion of resourcPA). Via%SIGNIFICANT IR-REVEFtiSIBLE'E1�iV�IRONN ENT1�L CHAN GES: SHOULD THE PROPOSED ACTION BE IMPLEMENTED 'Most of the irreversible changes in environment and irretrievable comm' is of toren resources Associated with this project would take place as a result of the nature of the proposal: to convey natural open space into residential areas. 1 Reduction of continuous open space character of the area; conversion to residential use. 2. Vegewtion removal: 3.1 wildlife habitat reduction. 4 z homes. Use of non-renewable resources: vehicle fuel electricity for 5: introduction of left turn iMproveM Mts' on Highway ;31 at Santos ay» Subject to evaluation by the fir Resourocs Board's determination of siohificence; pralect s cai£ribution may be considered insignificant, lei COMMIT, ATENTS OF RESOURCES - I$. SHORT-TERM YS, LONG -TER In its undeveloped state, the project site has value as wildlife habitat and watershed, and this value will be reduced sAbstantially by the Conversion to residential, use; fitter construction, the site will take on long-term value; as a °location for rural homesites offering the amerities of country living on the fringes of the Chico urban area.> reo p s The ervaton of agricultural land' on 'the w+.:stern side of the Chico urbanized area has long been a stated Goal of planners and community residents alike, To protect the fertile and roducti,ve a-, icultural lands, the areas east of Chico have been cans3dexed for cevelom..nt. if Wildlife development., .� ife and watershed values can be preserved, The project is ;located primarily in chaparral, a vegetation community which is well represented in Butte County. A review of the' vegetation° map prepared for the 197-9 � update of the Land tise Element of the Butte County General Plan indicates Approximately 64 000 acres of chaparral are Pp Y , P present in the Butte County foothills:. Approximately half of this area that portion lying north and %vest of the Tonin of j Paradise -- is protected by the 40 -acre mihIMIJtn parcel size specified in the Open and Grazing Land, Use category. The remainder is designated almost entirely Agricultural i Presidential, leaving it exposed to small -parcel, development. Those chaparral areas lying •within the Central Butte Stud Area (for which a zoning, at ry Study udy is underway?'..and thaw: areas near Oroville and to the southeast should be reviewed so the valuable chaparral, habitat can be';,uiitably protected; The Bidwell Heights' project is within an area: designated for, Agrica Lural Residential i:se, ':1 to 40 acres per c t -Ml ling unit; adjoining,a iarge •e:cpaase ,of troteated ChapartaZ which is designated as open and gran: rid. Loss of this wild , 1 ifs habitat Mould represent about 2% of the esticiated 64,000 acres of Chaparral. -A Elie foothills of BMA -11.-e County. Watershed values on the project site, although reduced y b dt velopment; will be preserved to a great extent by remaining open areas; project mitigatiot measures and cluster development patterns, AdJarelit areas will remain in 40 acre mi irium parcel sizes ander the Grating and Keen Lane: designation, Some short term commitments of resources will occur during the construction phage, when ttSels; labor and building materials will be put to beneficial use. In the longer terrn; enerV for home heating and transportation back ,and loth to Chico will be used on an on-,oing basis, Scenic qualities of the site will also change, fro.. natural chap. arrat to chaparral intehspersed with horn es and residential landscaping: u46 - X. 03ROWTH-INDUCING,IMPACTS Approval of this project could result n growth on several fronts. The tax base of the County would increase by the amount of the assessed valuation of the project, with corresponding amounts of taxes becoming nollectable. Subdivisions in adjoining areasto the north and south could be facilitated by the precedent of this approval, together with the improved access, the public water system, the local public services (fire protection,, security guard), and the utility extensions power, telephone, television cable) which will be established to serve the Bidwell Heights development. lmproved road access already exists, and is not contingent upon p pp possible, p ell Heights would like to roject approval. To the extent ossible the developers of Bide limit access to adjoining properties to emergency access only to maintain a. degree of privacy. To the extent they, are successful, subdivisions `to the east and west of this project have independent access and are not dependent on this approval. such projects are physically isolated by steep canyon Walls and are therefore somewhat isolated from the growth-inducing effects of this project. in any case, such developments would be much, less dense due to steep topography and sewage disposal, constraints. Frere are currently tt4d other projects underway it the vicinity. Canyon Va.rk Es -ateo, a Sk Xi.c Plan-i .,A e and Tentative Subdivision, propos � Recon,. proposes to r!�tidentia7 a on 1050 acres v i is located zip Sec tion. 11-1 tea. The other> prr for Isoti -VIa,1 . has not been submitted to the County of ^Utte for r eatew 4 n eotitated 'li to 125 residential hots are proposed on the SSD acre - �e tions 1, 2 z 1 and 1.2-, T22 , 1 1 or reference, the, Bidwe-1 lleiglits project is in Sections 6, 7 and. 18, T2211, RAF and Section 1.2, s.22ti, Rte'. TYe total prdposeti populatioli from the thrae proj,ectat within close proximity; is approximately 1.620 peop,e , in 620 dwel.lihg uft1t;a -+. "lnie total number o duel"i.ng units is 8peculative a<4, th-? s point: The figite of 2.61, Pelr8 ns Per household (1980 Ce..sus fi gap=) was used to:arriv at the figure of 1690 Persons. Bi.dwtell ltaights' wok..ml.cd m.ontribute about 1,900 persons to that total. It should also be tsted that the Fourteen Mile House Rezone and subdivision: W,I:t add to the cu!:ulative effects, partit txlarl.y traffic onto Highway 32 toward Chico. This 21 dwelling unit proposal, is oft a 168 acre site adi&cen,t t, 11ighway 1,2, about 14 miles northeast of Ohico. g As of April 1982;, there are six tentat:ive parcel maps pending within the Spesific Plan boundaries. A tentative map for Stan Laughridge and Hall and Isom Investment. Go-,also within the 'bQutdariesf were approved, by the Advisory- Agency in September 191311 and October 19BO respectl7ely. The list of tentative mans and !..he Assessor's Parn.el numbers are as follows, Doe V14.11 Vineyarat 46-71-75 Carl 11-lartellarc - AP 645-71-2F, -s= Investment "o. L AP 4&71-29 Hall and I Simer -jenning Chuck Jac-ob - AP Stan L-.,u�:%,ridss - AP 31-nal-1-40 Dick -Uhappell - AP 5i-o1-141 -Larry Ludwig - AP 51-01-143 or more t arcels are potential on the parcels dostribed below- 8ach tf the above parcel m4�3) proposet-, to create IL-bur parcel.� of 5 to 6 acres or larger in sizej:e�cept for ;,.8 and 4.7 acre parcels or AP 46-71-29,, and an 18.5 acre Parcel on AP 51-01-14-0, a total; of 23 parcels. In Addi'll-iott, there are setren other parcels WiL n the northern porLiion. of the Specific Plan. area of 20 to 34 acres in size th- -i a-ivlizion of those parcels in a similar zannex would yield P1 additional parcels or 23 4,-a 11al, Alsoj the 175.8 acra tarcal o� Doe 11-1ill Vineyards may yield .1.5 parcels of 1'. acres + in - size. All- - 0 - f these pbi'cels, except for AP 46-171-251 were originally created by tha Don -Hur,=,er, tentative map which received Advisor,+ Agency approval on J,=e 19'', 1ci78i, "4& III. ALTERNATIVES TO THE PROPOSED ACTION Four alternatives to the project as proposed are described below, with their attendant benefits and costs in. terms of ability to meet the project objectives and potential for adverse environmental impact.; In each case, theproposed project would' represent -a more favorable balance of environmental costs and benefits and would meet the project objectives of providing affordable rural homesites in harmony with the natural setting ' ,din alternative location would not be meaningful, since this site has i already been partially for residential development b. the Applicant. 1, No Project Not building the project would leave the property in its present state, and have the following effects; Benefits 1. None of the un i` avo dabledve' s a r e effects an theenvironment, listed. in Chapter 'VII (impacts on air quality, 'vegetation and wildlife,' energy use, exposure to fire and earthquake hazards, and increases in tra:ffie and public service loads) Would occur. 1,he project would not contribute to regional cumulative impact in these areas, The project objectives �voulcl not ci t' 1. he me 2 The resources used for roads, ells, ire equipment and other improvements Would . - _ Barred b,' the applicant. 1 2, Same Densityve Different Aistr' ibution A. No PA --C Zoning with nc+ clustering of hor��es the entire 1200 aorec, would be divided up into indepeiident lots to aocommodate the proposers number of un3Lts tv%,. 4omeowners Associations Would exist, and lots Would be sold and developed independently:: Benefits L, Aomesites Would seem more secluded and remote, as individual lots would be larger, C rests physical , _. 1 Adverse effects or the visual, yand biotic environment (erosion, increased runoff, habitat reduction) would be of greater extent and magnitude,, due to more roads and widespread grading and development, ..a cj WTI of buildout would make homes more expensive. 2. 1nefficiences piecemeal Absence.. of Homeowners' Associations would preclude method of payment 3; fire protection, security and transit, resulting in unmet ' for needed services, .mainly service needs and over -loaded -service agencies. of guaranteeing sound 4. Absence of P A. -C zoning; uo,,Rld provide no means ' use of non-developed lands even if homes were clustered in, some areas. future suitable soils for lots would be unf (,asible to develop due to l 5. Many he number to steep slopes preventing access, therefore toverall ' septic leachfields, or fact be lower than proposed, impeding project objectives. of buildable Units would in B. Entire Project C1Uistered, PA -C Zoning, This alternative either with Units :n several clusters., few large clusters or one the since ,large cluster on the property, is possible only by reversion to acreage, . _ approver for end tentatively land east and north of the va.neYar is alretY e �h sector nor th�o3thern The foixr�een di.ft'erent proper acre fats. '' � owners iii -sn overall P-44 rezone f ,22 acres +—i could po Lefit3coorerate Benefits Open space, =}+ilitlife habitat, visual aesthetics, land form impacts would be 1. _- through minimizing -roads- and- maximizing guaranteed -natural areas. minimized Project objective"; would be met, in terms of; densities and environmental 2. safe u ands. a f f icienlcy of o Wped Units, .fewer d throuti the e 3, Economies could be ach`iev roads and utility lines*t "%yould be relatively close together if clusters Vvr;re few and 1.os Residentscts dense. 3 Reduedd 'Overall Density i + densttyj either with or without -clustering ,would have the ' Substartslly reduced folluwing a "tests: . Benefits air 1, Project increment of ru;ntilative adverse pacts 'in such areas as vzsual aesthetics, traffic services, and utilities would be less? ' quality, Edd be Iessened biotic environ► mein t 2, Ads erre impacts to the physical hystcAl Mid t� 2�1 REFERENCES Butte Count Y 1. Butte County, General Plan, .hand Use Element, Eloise. Element, Zoning Ordinance aSupervisors 2. Butte County Planning Department.. (Sept..l 1981) Memo to Board of 3. u , Il Ridge landowners (August 24 1981) .Memo to Doe �1i State of C aliform 1. Air Resources Board. (allay, 1.980) Lecture . p atin �� dates far lyoxksho onchsDrvisron, ., Hot ars Ana v Caron Monoxide Concentrations for Ho Analysis, GARB Resea p t c ," Aar Quality Modeling Section 2. (June 17, 1'981) Predicted California Vehicles Emissions (EINIFAC 6C computer run for Sacramento Valley .fir Basin,,Butte County, 1990) 3. (June, 1981) Supplement 2 to Procedure and Basis for Estimating On- Road Motor Vehicle Emissions. GARB Stationary Source Control :Division, Emission Inventory Branch, Motor Vehicle Emissions and Projections Section 4. California admin. Code, Title 25, housing and Community Development, Chapter 1 Subchapter 4) Section 280 article I. "Noise Insulation Standards'" ` o y Patrol. (October, 1977) 11 jtor Vehicle Noise Laws 5: Calafornia Hi�hcsa Patr 6. Department of Health, Office of Noise t )ntrol. (.N 197) Estimation of ; Community Notice Exposure, in Terms of tl -Night Average Level Voi5e Contours Draft 7. (April, 1977) 1Mod,el Community Noise Control Ordinance. 8. Office of Planningod Research. (1918) An Urban Strategy far California Miscellaneous ort, Jara Applied Sciences, Inc:. (April, 1971) Paradise Pines Surface. Water Quality Report, p NOAA; Gliir,atological Data; ,Annual Summary o-Ana3 .ens: (April IC ) E1R .aor an�fo . Park Eata'Co-8 PA-, Rezone eq.fi `,Centative, t Subdiv.izi n" tto-Analysts: (PL-bruary 198 ) fi,TI f,*E lrourteen 1.1ile Hoase.PA--i_"+. Rezone-and Te.ita .iva SuW rtsion. RSwie Loan-y Planning I�iepartT,n-: (April 10) EI for Chico Area Land ITee tiara w rl if the units were clustered, if unLs were not clustered, lots would need to be a minimum of 20-40 acres- in size` to afford a comparable degree of environm-nta;l protection Casts.. li The, developers cocst per .u..t would increase if the same level of amenities and mitiection measures for services and other inxacts (fire Protection, ceGUrity ,guard., ; oa�rc-al area, transit system, etc 1, are includt4. 2. If prices of homos were t.`ept to a cPasonAble level, tca�vices and impact- mitigating measures such as those listed in item (1.) above would not be provided., resulting in t3nmet needs for thv8e vices and. increased demand on service agencies. 4. Increased Density If project densities were substantirily increased, the following effects would he felt even .,�=ith clustering: _ Benefits 1. Dollar costs per` unit would be lower, providing possible lot to rncder ate 111COfne- ilUllslha. costs is Primary effect would tje in ovevI., ding at•eas designated suitable for septic lertchf eldsisinee densities proposed Pefle�!t 5'ewage dis.pos constraints, ' 2. All project lncremen p y . is to ,offsite cumulat vo h� :=teal rand urban service impk.ets would be significantly larger. 3. Ori-site impacts to btological, 4.sua1 and physical resourees w6U16 irtcrease and be harder to mltiate including g , ' exposure to fire and seismic hazards. L'! 4 PERSONS AND ORGANIZATIONS CONSULTED State ;of California Air Resources Board Michael Redemer Ed Yotter Susan Scott Chico State, University Richard Haiman, Professor, Department of Geography _ Fish and Game Department Jim Snowden Bob Mapes Forestry Department Hector heed Transportation Department (CALTRAyS) Bob Burrow Sam Johnson Gene Abshier Bill, Wells Dick Ayer Fobert Ski trore Health Department -Office of Noise Control Jerome Lukas County of Butte - Air Pollution Control District Richard Booth Environmental Health Department Ilan R lsnyder Fire Department Dan Costello Chief hick Tiller Planning Department Charles Wood% Advance Planner Steve Streeter Public Works bepartrnent Robert Jones Stuart Edoli Sheriff's Department Wi_lliata 01hei10 Richard 1MIush, Lscutenant City of Chico - Planning Ddparttrrent Toni Lando, Director l.d Palmerio pinnnrrt Unified School District Bcti Matthews, ire6tor o tlo.meotaey Education California Water. Service Company, Chico Gone Grant, :District Manager Pacific Gas & 'Electric Company R L. Lind, New Building Representative Jeff Bl;'nc, Residential Conservation Supervisor Pacific Telriphone Company Carl Turner EIR PREPARATQRs This 1JR vias prepared by Earl, Nelson and Barbara Castro of Earl U Nelson Associates, Chico, Californias with the tXpert assistance of the following corltributo„sand Philip Lydon - 0,eol6gyT _- Jon Anderson - Soils, Kingsley Stein - Vegetation Roger Lederer -- Wildlite James Manning - Cultural Resources _., 0 L 1 YE8MAYBE N4 h Exposure of people or property - - to geologic hazards such as earthquakes, landslides, mud- s'li.des, ground failure, or X similar hazards ? ---- _--- --- 2. Air. Will the proposal result in a. Substantial deterioration of ' x ambient or local a r ou ality? � b, The creation of objectionable X odors, smoke or fumes? - --- c'.gnificanL alterationof ai-r ' movement, moisturee temperaturimate, or y ng in clor changeeither x locally -_ 3. Wat�eer. Will the proposal result in substantial: a,. Changes in currents, or the course or direction of water I x movements? _.---�- b. Changes in absorption rates, drainage ,patterns, or the rate c and ainoun't of surface water , 'r-unorf? C. Need for orf-si-te 'surface drainage improvements,_ including vegetation removal, channeliza- x tion or culvert installation? d.Alterations two th- course or x flow of flood waters? _ -- e. Change.- the amount of surface X water in any water- body? f. Discharge into surface, waters,; or in any alteration of, surface water quality, including but not limited to temperat"Ore, x dissolved oxygen or turbidity? g. Alteration of the direction or x rate of flow of ground casters?, h. Change in the quantity or either quality of gr'oUnd waters, through direc+;. additions or taithdrawals,, Or "through inter' ception of an aquifer by cuts' or eXcaVations? -------= YES MAYBE VO i. Reduction in 'the -amount of water" otherwise available for public or private water supplies? x J. Exposure or people or property to water related hazards such as flooding? XC 4•4 Plant Life Will the proposal result in su st,anti;ilo a. Loss of vegetation or change in, the diversity of species or number " of any, species of plants (including trees; shrubs, grass, crops, micro- flora and aquatic plants)? x b. Reduction _of the numbers of an; unique, re or endangered species o~ xr C. introduction of ne€r ipecltof,` Plants into an area, or is a; barrier to the normal replenish- ment ,of existing species? x" d. Reduction in acreage of any agr icultur-al crop?- X 5. Animal Life. Will the proposal result in s—U�stsn�i:a1: a. Change in the diversity of secies, or numbers of any species of' animals (bards, land animals, including reptiles, fish, and shellfish, benthic'organisms, insects ar'microfauria)? k b;i tceduction of the numbersof any unique, rare or endangered species of animals? c,. Introduction of new species of anittals Into an area, or result in a barrier to the migration or move"beht of aniut6ls7 d Zeduct;oci af; encro'acnttent upon, or deterioration to existing fish or wildlitt habitat? X Noise Will the proposaj result it std"batant ial. ; Ai 'increases, in noise Io els? YES MAYBE NO -- - b. Exposu4e of people to severe noise levels'? X; 1 7. Light and Glare: Will the proposal produce significant light or glare? x 8. Land Use. Vill the proposal result in a significants a. Alteration of the planned land, use of an area; or establish a trend. which will demonstrably lead to such alteration?, x b. Conflict with `uses on adjoining properties, or con- flict with established recrea- tional) educational, religious or scientific :uses of an area. '` x 9. Natural Resources. Will the proposal result in suostantial a. Demand for, or increase in the rate of use Of any natural resources,?' b. Depletion of an,+� non-renewable natural rersourc(a? x 10. Risk , of Upset; Does the propos=al involve a risk:of an explosion or the release of hazardous substances (Ihdl,uding$ but not limited to, oil, , pesticides, chelticals or radiation in the event of an accident or 'Upset, ;X 1.1. Populat ioh. Will the proposal . igniticantly alter the location distribution, density, or growth rate of the human population of an area or physically divide an established cotimunity or facilitate }{ development of adjoining properties? Housice: Will the proposal sionifl cantly affect e�cisti.ng housing,, or Create a d;et,1and Eor additional housing?+ 13. Tr;rinsportat ion/Ci,t u�ation. Wlll the proposal result in a doh6tatiOn of substantial additiohal vehicular movement? X' YES MAYBE X30 b. Significant effects on existing' parking facilities, or demand for new parking? x C. Substantial impact upon existing transportation systems? X d. Significant alterations to present oaCt.erns of circulation or movement of people and/or goods? x. e. Alterations to waterborne, rail or air traffic? x f. increase in traffic congestion o hazards to motor, vehicles,, bic clis�s or __ y "` pedestrians?, x 14. Public Services. Will the proposal, have an errect ucon, or result in a tubstant ial needfor new or altered - governmental services in any-of the following areas:, a. Fire protection' b. Police protection? a, C. Schools? , }{ d. Parks or other 4recreat-ional fac:ilitles _ x e. Maintenance or public facilities;` including roads? _ x f . I other governmental services? x 15. Energy. Will the prbpos,P.1 result in a. Use of substantial amounts of fuel or energy! b. Substantial increase in demand upon existing sources of energy, or require the development of hew sources of ehergy? }t lo. Util.L'ties: Vill tha proposal result in a need for new systems, or Sub- stan't ial alterations to the following utilities: a, rower or natural gas? �'-.5 .... 10 YES yy+O MAYTTryry �l — _-- b, Communications systems? t X x c water d. Sewer (will trunk line be S` xtended, providing capacity x to serve n->w development)? -- e. Storm water drainage? X 17. Human iaealtJi Will the proposal result in': :a.-Grea:tionof any. health hazard or potential 'healt<h hazard x (excluding mental health)? b. Exposure of people LL, potential X, health hazards?------- 18. solid Waste. Will the proposal result in any slgni'ficant impacts associated with solid waste disposal, or litter x contLoi? �. ly. Aeshetcs. the proposal ,result: any - in the obstruction o= public -designated or recognized _, Genic vista open to the public? Wil.1 the proposal result in the creation of an to aesthetc9l~1y offensive site open public, view,j rriill the proposal significantly alter the character of x the area? ------' 2C Recreation, Will the proposal result in an impact upon the quality or quantity of existing public recrea_ tion factLLties? Archaeological/Historical: CiLI `the 21. pro rsa resu t in an alteration of -or sppriif�icant archaeological bit>tor.caL. .site, structure; object x orbuilding's' 22.. Mandator Fndiris of S t1iritance: a. Does the project have the pot etitial to de tade the quality of the environment, suDstaaLLsllY reduce thy; hablta.t of fish or wildlife species, cause a fish of wildlife V-8.: BIdweLL 'fieigt ® - T�{>�,1� _. $2-03-67-02 I Mjedt r/ 82-6 Specific plan, rezone :and subdivision :+o x • ., , The project is a subdivision of about 1210 acres into around 3' .mesites .rith appurtenant services.� - �xhor ♦• West side of Doe Mill Ridge) 7 miles NE of Chico, between Little Chico u Creta�` gk and Doe .loll Ridge Road. Portions of sections b; 7, and 18 of T22N, R3'E�MDM. and a portion of Section 12-oE T22N; R2E RDB&M• ;, Vg,.. acresa _ 1 DU/- .4 • w ^.eJ i �r,`i i 'r' + i .'. 6it1: �i:L13"-.`. ' t,'y: ♦AAArOX. 7 percent Of prosect area oTa 5. 6• Access would be from Highway 32 via 'Santos • gra~ ♦ extension, through -Isom-Hall. proper-ty; Doe %1111 Ridge RoadWay Lies to_the east. Individual septic tanks. ,1�R individual we1Ls Pr:rjxlt"s :i .x �_ "Pow'-- Lir EXisting t b project site. y «" +. '�� Pfl x" '' Y i1i ' . yy" t :" a Ca,'w.i `+ tl t[ r =" � .iCit�rCt AQrictjltural-Resi= ryry ; dential designation allows for 1-40 acres/DU. v«�" i+• i �1.J,i " `t" + w �t x .,• t lat to gently roiling upland West o:f - • � Dae.. Mill Ridge, with small. steeper portions as Chico and "Butte Creeksz Land,slo es to Little'. Ithdo r 51. on main uolandPortion, 100% on eastern slopes. 30m!-� aC north, west, sou h margins. 1:160 - 1640 .feet the fiat tgland is a,t.around 1&60 feet. „,,: _ e• est°. sinaLL areas of stee slo es max. r Toot:es tothin funder feet tliill to er 5 feet deep in sone parts,,a'.star:', reddish m+ with_low tb MQ& era a ish-brown clay lda :subsoil ddrmeability and rcediuti to '"rapid runoffF _ jtSeyere' limitations+ ratihg for suitability of septic.- Dank b. leach fields: r �py Md.derate Earthquake Intensity Zone V111 - .' ♦]."".A='i r,1: Slight, I= a•' . b H lY r{oderate 1. Loco tt� :�Oder'ate _„ «.• A small 'stock wate'rint; 'pohd is oit."ito-d,near _Ehe _ecitte . The ptoperC:y._ U"t8=zssiol, ,. Bidwell Heights,, p.2 b. G.L'oui,,d Wa,tc,r: Available from, local nr3if6r. 70.0 foot deep well existing. c. Draixtage Cg,-araeterit; LiCS. Property, is drained,by several intermittent tributaries to Little Chico and Butte Creeks. d. Annual Raiiil.all (noI,I.iaj, Approx. 40-45 inches/Year. e. Linj1 win- Fae tor» None known }. Vt:8tial/0 ,: en C ;uality : High A.oOus ti c �3uality : Rural, -open land character. Air al _ y : Good L 81 Vegetatio,j: foothill-ridealand character. Seedling Ponderosa pine, digger pine among oafs; chaparral anu large grassy, areas. Large areas have been chained (about eleven year -s ago an are now reuegeta ing as ybun c Aparna . 9. Vlil dlil e H6Lbi ta.t : Upper Sonoran rife. Z,a,4,i, withabundant wildlife, Including deer; Cultural En vi ronmen t, : '!G Ar haeoligioal ar3dst;arical":esources in 4'rke area: one recorded site nearby:. Property is potentially, sensitive. Archaeological cl.eararce riven as.r�r,r�t I, SU4�e Count; -al --� • �'�' y' - Gene "^� Plan de��;rla,t,iar.: Mostly Agricult'ura��esYde;ntial (1-40 ac/DU), with small areas at N and,_S ends of Open -Grazing (40 ac/DU minimum). '1EXisti .19 Zonilig: A-� General '13- .: sting Lana FIs e on- Si t,e : One vinpYard„; rgM8Liader is ondn land with seasonal` grazing: +4. SUrroUndirg hrea s a La: d Uses C Open foothill and canyon land, with Light grazing and widely scattered homesites._ b. Mostly A-2: C. Gen. Plan designatioy fi Open -Grazing *pith.. areas Agricultural -Residential to soutLhvtest a0d :further to east and northwest d. .Fardel S.�,,E:a :, 20_' 100 acres: e ' Population! Scattered rural.' 154 Character o.P Site and Arua,, Open foothill terrain4 t4idely scattered ,*4s sr IE. 140arest Urbam Area:, Chico 7 miles soutl;vest. 7. Rlelevalit Spheres of Lif"luiuic, :3.A: *V�t. Firo Pr6, to -e ion Uetvle :: CA Dept. of P6restry - Chicois d., Vuare'su vouYtt (State) Fi L, S,.€i.t1.on. •.s lid. stations ,Y srx � � ` � y J ' , � �� z , Fair St- Cohasset bi Wat.G1' Availability I Stock t,,ateriiuz pond within project area. 2c, ,"iCh( uls in ,Arw� Chico Uriil lai .gthool 11i.atrict 4pelldiak P ,y a e o Bidwell Heights Appiicahion 'ITT. DISCUSSION OF ENVIRONMENTAL EVALUATION roject information summary is included in preceding, Discussion- sheets) la b, c: Development of homesites in hillside areas would result in excavation, earth movement and,overcovering due to site preparation, and construction of roads and buildings. Excavation and grading may .result in unstable, cutbanks or fill areas although this concern should not be significant if grading requirements of the uniform Building Code are complied with. 1e: Grading could expose soils during kainv season or dry summer, increasing risk of on-site erosion. Improper channeling of increased surfacerunoff could cause offsite water erosion of soils. Existing cutbanks show l ttie evidence of significant erosion> however. 1fE Soil disturbance from grading, and vegetation removal within the Little Chaco Creek or Butte Creep watersheds m y result in erosion and siltation ot the st+•pamsf - ihe Building.oslopes :could subject hotmes to rockslldes; fractures in the n area may be associated with seismic activity� and may be unstable during seismic events, This hazard is common to the California foothills. 2a The addition of commute traffic o� up to X85 homes: to and from Chioti would zdd reactive organic gases, nitrous oxides and carbon mono ode 'emiQ-sions the, air basin`s air pollutant toed, Mixing in large air to should prevent accumulation of these pollutants at this rural location. 3b: The creation of roads, driveways and buildings will inc°cease the area of impervious surface and thtits incre'sd surface runoff. Drainage ,patterns Cou1d. be changed by grading activities: `3c d; flout volumes and velocities may be increased,` necessitating measures to stabilize channels and reduce velocities to prevent erosion, potential down stream flood problems should be examined in light of potential ruiOtf intreasest E y expected to,be signifdant (see ,though the are not exect 3 j)•. , a Bidwell DISCUSSION, p. Z 3f Construction and improper maintenance of roads or homesites near drainages .may contribute silt, increasing turbidity of surface waters; storm runoff traversing homesites and roads could carry residues of petroleum, pesticides and other toxic substances typical of urbanizing areas 3h, i `q,uifers could be cut by excavations, for homesites or roads on hil__Ides Groundwater will be withdrawn through wells for water Supply; adequacy of groundwater supply for sustained yield should be verified. 3h: The Environmental Health Division indicates that rareas 'proposed for highdensi-tyon :septic systems will require proven soil -depths_ of over seven feet located where tests indicate sewagel will not percolate on.substratas. The existing well, yielding over 300 gallons per minute, could serve much of the rezone area. Additional well sources would need to be developed to assure ample supplies for domestic use and fire: protection. Water availability is not con-- firmed throughout :the rezone area, 3j: Flooding downstream is not expected to increase significantly due to this project because of the comparatively large size of''the drainage basin. 4a: Clearing for access roads and homes could r=emove a significant proportion of certain vegetation types, depending on placement of homesites 4b: Bidwell -Is knotweed. was observed on the site by the botanist on several slopes. Mitigations were, not deemed necessary. 4c: Human habitation inevitably brings new species of house, garden and landscaping g plants into a natural, area,. Sa,c,d: Construction of access :roads and homes would eliminate some wildlife and encroach upon the existing wildlife habitat. This will reduce the wildlife carrying capacity of the site: Animals intolerant oP man's presence, or those whose specific habitat type has: been reduced or eliminated will relocate to other areas initially and may displace existing wildlife or die off. Any dogs which are allowed to roam free may become local predators and chase deer and other wildlife; road kills from incteased vehicle traffic would also inctea:,e with development. The California Department of Fish and Game shotes this area as part of the East Teharta Deer Herd winter range on the Area of Special Biological Importance map. Forty acre mitdmum parcels (or a cluster atrangeinent of dwelling units with comparable effect) are required to i:n5ure .migratory deet' herd survival. the pJrojc eted development density~ is approve' d, they anticipate the will. be destroyed t for wildlife habitaOfd-site and cumulative impacts to Little Chico Creek and the w'ildilfe habitat are also stated to be key coricerr,8. Bidwell DISCUSSION, P. 3 6a: increase in road traffic and human activity 14ould increase noise levels over the quiet ambient levels in a natural setting. Via: The proposed project involves parcel sizes larger than the one_ acre minimums specified for the Agricultural -Residential land use category, which covers about 90 of the property. However, how much 1^rger lvould be appropriate depends on the application of "conditional criteria"' which are subject to interpretation; Appropriate densities ri light of General Plan policies will be determined through the public hearing process. Sb: The development could affect wildlife habitat use of surrounding areas by the �ntrodurtion of nblse,; traffic, humans and their domestic animals. Caltrans comments that the project appears to be inconsistent with the goals of .the State's Urban Strategy, ?.,e. to use land that is immediately adjacent to urban development when e-x-par�ding beyond existing urban and suburban. areas. Pa,b Some amount of natural resources would be used :for construction of roads and residences Upon completion, the use of non-renewable resources for heating, air conditioning and appliance operation, as well as commute travel, would occur at a sustained level. The residential area �4tould significantly increase the pope- �. in the Doe }dill Ridge area. it could, by precedent 11 1 -facilitate tle�relo merit of adjoining 1at�.an density and g7owth-inducing impravements; p properties, resulting in an increase in the population growth rate of this area to satisfy the derrmand for addi�tionalhousing. The Bureau of Land Management believes that continued development in this. area A%,ill eAtentually fi'cant impact on the public have a szgxli1. I c.t area to enable lands They further encourage a rpezone of the role orderly and proper: growth. 13a,e,dt The proposed 330-385 units could generate approximately 2300-zloO new daily trips on Highway 3�i Present traffic counts are r traffic Impacts ,under' �tl00 traps/day. Caltrans is concerned about to Hightva � "s and Sant -os 11xay, Left -turn channelization Would be tivarvanted at that inter=section with the'cost 'borne by the applicant unless the Count i_.r able to share in t}io cost. They requested that needed roadWay improvements within the State right-of-way be studied as to the canstruetion-related impacts, including vegetation removal. grading. Departmen The Public works 't states thit "for aproject and g g of this size and density, gravel roads are inadequate". A circulation. route from the soothe -0 end should. be veejuired. They note the project area; within 5ettion 18 is not within the existiiig,}ountain Recreational Area as de, igna.ted on the. map, 13f'� increase in traffic hazards to motor vehicles could result from the increased turning, movements at Santos 1�Yay and Highway. 52, and, from heavier traffic on. na.`roia local rows such a5 nae Mill Road. Bidwell DTscusSTONI, p. 4 14a: Some form of ensured fire protection will be necessary since this chaparral:. area is one of high fire danger. Provisions may have to be .made for an :additional firetruck and adequate water supplies. l4b County sheriff or other police protection are not readily available for the residents; new routes or a -shift in personnei may be required to cover this large development, or the residents would have to be content with a low level of police protection. 14c The Chico Un ool District indicates the proposed subdivision is 12 miles plus from the nearest elementary, school (Parkview) and 3 miles 'plus from the nearest junior (Chico Junior) and senior (Chaco Senior)high schools. Bus transportation would be available unless District policy changes. Building new a school, expansion of 'present school sites, and t busing of students are future alternate means of housing additional students. Any expansion funds must ,come, in part,, .from the developers. The increase of uribute p to X85 families would. contabout 193 children to the school district, possibly enough to necessitate school expansions. potential residents of the ro`eCreat anal facilities will occur 14d: The use of arks and other recreational by p project t to an undetermined degree• 14c: Due to additional traffic on local unpaged or unimproved roads, the County may have to improve or maintain certain ones to maintain t ety. 14f The provision of public services such as building inspection and -josquito abatement i4ll be more costly to provide to this outlying location. The City of Chico l icozCommented about the County's ability to provide services to service propose nisms Fd and. mecha P _ rvxces c+€ ll be addressed in the Specific Plan. to a.� for those se lsa: Increased amounts of gasoline would be used in commuting to Chico, electricity and gas would be used in significant amounts for home heating'; cooling and appliances: 15b Substantiall)r increased demand would be placed on the electrical p y p s a Toad increase in summer ower distribution system, especially a months. l6a,b: Telephone systems ssiltheh esiderttd-usednelectrichit)",tsolar as would natural gas) ,unle y power or bottled gas: poop, maintains the power line which traverses part of the site A 10 foot minimum setback from the centerline Of the facilities is rec.otnmended for Homes and, wel 18 Bidwell DISCUSSION, P. 5 16c Refer to item 3h l6e: Surface runoff may be sufficiently increased by impervious surfaces, that at some point, a stormwater drainage system may have to be installed. t r Potential malfunctioning of septic sy=stems could create a. 7a,b. health hawa d 'in.i0iich ground and surface water could be exposed LO! vaste}Yater contamination. The possibility of rattlesnakes and Tabid skunks in the tifiicinity would expose people to potential, health.. hazards. I. The residential development could detract from scenic qualities of views from Hi7hiiay s2, and may al`tex 'the op p Iter of en-s ace chary the area. The Bureau of Land Management has expressed concern about the impacts on the scenic qualities of the canyon, Architectural design, compatible with the environs, is recommended. 21: An archaeological survey has been performed with ulear,ance recommended since no significant archaeological sites 1,mre observed. 22a dost of the 'wild y p ♦ lafe habitat would be eliminated b the proposal at full buildout. 22b The project would provide housing opportunities in an area the es'. The ultimate residential use at densities tual res�.den�Y wyll need to be General Plan designates or even between 1 and 40 acres. balanced ' with long-teras goals of the General. Plan; such as discouraging urban development isolated from existing development and urban centers unless such a need can be determined (Open Space Klement) -regulating de��elopment in xdenLxfied S�tinter deer ranges to facilitate the sur vival of deet herds (Land Use Element) and encouraging adequate fixe '. Safety" �letnent) . p g �h protection services in all areas of opal anon ro�tith and high recreation .Use ( c� Project impacts which, though individually limited in seireritjx or scp o e, add up 'to make the project a source of considerable impact, particularly 14htn criewed together with adjoining proposed developments' impacts erosion and stream sedimentation reduction of wildlife habitat significant increase in local population density increase in "ehictil.ar air; poll u.tant,em. issiong, gasoline use and trftftic 'from Ghit6 commute earthquake hazards g railability and supply' r oundwater a increa�sed,traffic� impact on on= and off �site Toads; circulation pattern r 'IV. DETERMINATION (To he completed by the Lead Agency') On the basis of thi8 initial evaluation: 0 find the proposed project COULD NOT have a significant effect on, the environment, and a NEGATIVE DECLARATION f I find that although the proposed project could have -'a significant effect on the 011vironment, there will not be a significant effect in this case because the mitigation measures described on an attached sheet have been added to the project. A NEGATIVE > DECLARATION iS t�ECC:T° IEIM D I find the proposed project MAY have a significant effect on the envaranmerit r ansa an ENVIRONMENTAL IMPACT %zEPORT is required, Date April 8, 198- _ y (Al Stephen Streeter Senior 'Planner , por, ' uu e otn y qnn.ng eaf` I Appendix page. 9' a£ APPENDIX B PHILIP A. LYDON • Consulting Geologist Q� 2948 San Verbena Way,Chico, California 95926 (916) .343-9277 `. October 13, 1961 e G OLOGYNtD GBOLOGIC ;? ZAVD5" OF N ARIDA :ALONG LITTLE OHTCO a.- t, ;u; 1. RIOt=E, B TE 0OUVi1', 1 z'+ITl?Ui71,CTi 0'. �.wo �,rre ula.rl sha � reels totalling about 1900 T g y_ p pa acres are being considered for .low-deris.ity residential 'development. .later is - to be deeloped: on-site, and sewage disposal is to be by individual septic systens. r nd 12 The parcels include parts o` Sec�ions 1, �, 11, a T^2� , , =, grid Sec: ions 6, 7 and' 18 , ,i'22N, R3'R. 'Phe �t2 µ westerly Isom-=Fia11 'property TICIudes the canyon O Zrittle 1 Chico Creek and an isolated upland remnant to the west, The easterly days property lues mostly on the upland o t)oe :fill Ridge. approximate property: bot;ndaries ate sho%M - on the attached geol.oaiCal_ 111ap, T'he site zetas ermined on October 3 and 4 1981. TOPOOPIAPOY ,�9 P g Y rolling: Phe Doo Mill Ridge ti iaii+� is �1at t5 �etnte Slopes typically average less than 15% � pot 'hundred Wit') over much of its su.r`ace'.; ua-' eastern margin oz` the: Ridge, steep r apes up Lo 100,,'o are common, whereas slope8 of Sq to 4Sa border LheRidge on the north, Wort, and h th margins ot proposed develr�ptnent site. Topography, inUthe estornparcel is rnore irtegular�. Thele are tlat or i j. jjeo Creek and on the gently-slopincJ areas near Lia ttl e +C� upland remnant in 881/4 5ec�. Z. �ls�tshere► slopes average from 5 to HCl° � 1)06tpite the irregUl:ar terrain, none 0 tl Lydon-. Page two October 13, 1961. proposed lots in both parcels is devoid of land having at ,least some gentle slopes. Little Chico Creek .flows southwest through the western ` Tributaries flowing east and west into the Creek carry parcel. _or the cart '' 4y, and account Yon -and -ridge topo- water ntermittpnt gra"phy that dominates the areas below the relatively -flat upland ridges,. elevations range froth 620 to '780 ft along Little Chico .: Creek, and from, 1360 to 1.640 ft on the upland ridges, SOILS According to the Soil *.L,bttservation Service by soils of the Toomes"Pentz ASSOcia-tion. ,Parcels a r. e covered soil, which is dominant on the; slopes Of the sitea, s Toames sl1 ht1 hard, cobbly loam. It `tends to be g Y ' typically a brown, 2 thick, but pockets of greater depth are prLesent less than ft- Clay content is variable. Toomes soil tends to have Moderate subsoil permeability, medium to rapid runoff, 'hiah erosion hazard, low zhrink-swell fo beha,�ior, and a „ severe liMi tation" ratIng r suitability a n septic -tank leach fields. ' _,. g , D%f_,erent soils are developed,on she Looe x zll did e upland on the Chico f"ormati on and Lovejoy Easalt (see geologic map and distribution of these Units) � Soil on Doe LCh i Ridge is for typic liy' a stony, reddi 8h-bro�w"n clay loatr,, which in places is overlain by a sha llo brot� loam:. The clay loam grades down- yolcan�c-muc,�lowrockt wh ch becomes Pro" ward into weathered gressvely harder and more compact with depth. Soil dt�pot va r,i es f too place place, ranking focti very shallow t or 5 ft Shrink -swell behavior appears to be lora to moderate erosion hazard slight, and permeabilitY PW to moderate, foil on Wvoyr 8asalt tends to be a gray,i.sh-brown stony '?s s tYla N o r, 2 ft loam that, over mu�.t'a t�f �tg �'�.t�'ntsi'C�t11 thick. Sail Otiginatl'ng directly theChico"otmrltl.l7i'1 1S difficult to .sre, because it tends to be mired with T 7scai - Lydon page three October 1-3,.1981 derived soil and rack debriL> that washes in from adjacent slopes:. Where it can be seen, it is a tan clay that is pebbly or sandy in places.. it is very plasi.i c , and should be expected to have high shrink -swell activity, low permeability, and moderate to high erodibility. tGEOLOGY O THE REGION Development of the ancestral :sierra 'Nevadal which ended some ' 125 million years acro, resulted in the formation of folded and faulted masses o` rock that now ,are exposed in canyon bottbh,8 east and north of Faradi,se. The Foothills Fault System was `Formed during this t ime. .Ltex a tong interval of eros,ion., an ocean encroached on the Paradise area; and sediments of the cw.ico :Formation were deposited. ALfter regional uplift and another long period of erosion , flows of lava (Lovejoy Basalt) deposited of Paradise. were west and northwest i Yet more erosion followed. Then, about 3.3 million years ■ ago, a thick sequence o volcanic mudflows and associated volcanic sa Is and°conglomerates--Mscan Fbxmatlon) Covered - -the region. Basaltic lava later flowed toward the Sacramento Vallee along the future course of Meer Creek (2.4 million years 1 acro) said Cdhasset `Ridge (1..1 Million years ago) CHarwood et al. The Foothills Fault system, first developed during forma- tion of the Sierra, apparently was relatively inactive until, the last few million years (Dept. -Tater Resources 1979), It is; ccnsideted to be tlse source of the seismic ac4ivity in the Sierran foothills between Ati'burtl and orrbville, including the ' .� e in the Foothills Fault zon i975 drovi,ll.e earthguake,ear sh _ Sstem near �" ft trend with tho Ohico mohoclino) Y Gro+��le �.s o n rocks that foritis the g which �s a fold in usca e straight eastern margin of the lacramento valley north of Chico: this suggests that the Foothills Fault 3ystom continues along the ea8tetn foot1lil.ls of the .alley toward Red 81*af E, ''1n � x.1.1 _ . c3.eflhed gone of sera ll faults and, fractutes ektehds Lydon page four)✓ october 13 , '? 981 from :near' Lentz to near Red. Bluff. through the Tuscan Formation r recent study of this zone War -,et ai. 1981) leads to those conclusi{ osi (i) Faulting occurred after deposition of ' the Tuscan Formation, and offset rocks that have been nacho-. metrically dated art 1.1 million years; (2) The age of the most recent fault Movement ip the zone is not known; (3) 'iawever, L 1 meter high near, Red, tuff the existence of fault scarps suggests ult:movement "undoubtedly took place in gg that some fa the past million years"; ar.d (4) Folding of the Chico monocline and formation of its many Small faults probably occurred in. response to movement on larger but: deeply -buried faults. I GEOLOGY OF THE SITS Three geological units, all gently inclined toward the ' south-west, are exposed on the parcels (see geological map) . From Oldest to youngest they are: ' (1) ' Tan, sometiMes sandy on pebbly, claystone and clayey siltst easily -eroded one o� the Chico Formation, This sofa and unit tends to be covered by rock and soil debris trashed doz,*n onto it from adjacent slopes. (2) Fractured black LOVv? oy _8asalt, This 'unit is I1ard and `n conseguentl'y> it forms either steep bluffs resistant to crosio t where Cut by a stream, or else broad, flat benches near Little Chico Creek. The rock is heavily fractured, but nonetheless is relatively impermeable;:!so that small seeps, springs, and boggy spots ,form at the base of the overlying Tuscan Formation. ( 3') TuscanForms ti,on, c ansisting of a ltornati n9 layers of vrlcanir-mucflow debris (tuff broccia) and voicanit sandstohe , and conglomerate, The mudf lows are telaUvely ix.pormeable and intertileninc� layens of volcanic sediment art relatively permoableyi a.s a rdsult, tr,ecs and brush alloh thomsellvc- in almost - t , q the permeable" ho ritontal s,.r_� oes on can} on grails 3 r �CSliowS.n rock» volcanic -sediment Layers predominate in the lower part of t'ho Tuscan Formation) whereas mudfloj,t layers are'domilnant in the u.ppen part. W tLydon pa"g;p five October 1�31981 The'mudflow layers are well cemented and hard and thus usually form steep erosion-resistant bluffs several to more than 50 ft high. Intervening Layers of softer sediment tend to form gentler slopes when eroded: The Chico Formation and Lovejoy Basalt are exposed on the site only along Little Chico Creek. Ezcposures in the adjacent wcanyons of 'ittte and 'Big Chico Creeks indicate that the Chico Formation is present beneath the sit at- elevations. of 560 to e680 ft along a northwest-southeast line. Because of the gentle southwestward inclination of the rock units, the elevation, oA. , the Chico Formation on the site shouldbe slightly higher L-) the northeast. The Lovejoy Basalt upper surface is at an elevation of about 800 ft along Big and Little Chico Creeks, but the unit is not exposed. along 13UtteCreek. It ;probably underlies all of the Isom=hall: property and the western part of the :lays property. ' The depth on the site to ancient crystalline rocks of the sierra hI'evada is 'not kno;m. However, the Chico rormation is "more than 500 ft thick in upper Butte CreeY canyon about 7 mi north (i arwood et al.. 1981) , and so should be thicker than that at the site: �,umerous lineame-tts are visible in air photos o� the Numerous p " �_ site. They consist of trees and brush aligned in .straightor slightiv- Curved .Eines; These lineaments represent the surface traces of the faults and fractures describedin the section on, regional geology. Sot -to of the, lineaments trapped by 8arwo;od at al (1981) are not evident on the 1975 low-level black-and;-white air photos; these I are shown on the geological flap as dashed lines. -Several lineaments Vere OXAMIned in the field vithout finding any. positive evidence, such as of�set 'strata, that they, are faults. :�onethel'ess, the following evidence surrg�?Sts that some o them; at least, probably are faults: (l They lie withirt the i11 defined ZoneL ,of faults and fractures described by Ka;rwood' et al; i g 1) (2) although not all the lineaments examined bv 14arwood et a1 •1 s"ho- wod "bf-sets of ad jaceht rock layers, a '.Largo percentage did, onough so that one would have til recognize ,widespread small-scale faulting as, an essential feature of the zone of lineamohts; (3) At least some: 'of the recognized ,faults Lydon Pg a_ e six october 13, 1981 are relatively young (movement within the last million years); and (4) fl,Iodern recorded earthquake activity within the zone show; • g -- at least at de,ths of a few .kilometers-- that breaking of rock p is an:activity occurring intermittently at the present time. HYD?,OWGY A hydrological assessment of the parcels will be made by ' Jon _nderson, so a few general remarks here will suffice.- The only permanent stream on the site is Little Chico Creek, but all the major gulches and many of the smaller ones can be expected to carry Iow flours of water intermittently during the. 1 rainy season.- Ancient Crystalline ,rocks. or: the Sierra,, the Chico Formation-, yield -no no or only small -f lows and the: Lovejoy Basalt generally y Of wester to wells, chiefly from intersecting fractures or perm- eable layers of limited extent. Pecause the Chico Formation was deposited in an ocean, contained water Might be saline or brack- t ish:, although flushing of any'permeable layers by groundwater movement might have replaced some of the original salty pore, „ water -,with- fresh water. The Tuscan Formation contains interlayered permeable abedi men a ) permeable (Mud-low), la ers , with t ry and tmY the permeable ' ones being more abundant iri the IOVer part of the unit, Because the underlying Lovejoy Basalt tends to be impermeable, water its ' the lowest part of the Tuscan usually will: not leak through the Lovejoy; but will be transmitted laterally until it intercepts , canyon walls. This general observation is borne out by the presence Of several small springs in the lower part, of the' 'iuscan within and outside the parcels;, and by the fact that a welj near the ponce in 31,4 1/4 bec. 7 yields a stibsta'ntial flog of ,,,ater from a depth of i0o 'ft (b. flays) oral communicatloh, October, 1981) . [Since the urell is at an elevation of about 1600 subsurface the projected bsurf ft, it pepenetratedd to wit) in 100 ft of p ace elevation of tho Lovejoy Lasait, or within 200+ rt of the pro= lected: elevation ref the Chico FottnabiOfto � 1 Lydon page seven. October 13,, 1981 Volcanic sediments in the Tuscan formation do not have uniform nater -carrying properties, because of variations in grain size, clay content, and distribution of pare -filling natural cements. Therfore, the water yield of the Tuscan should also be non-uniform. ' GEOLOGYC HA/ `SRO 1 Hazards not likely to 'pose a significant oroblem Subsidence. Rock types present on the parcels are of a type ,in which extraction of subsurface fluids will not result in sub- ' sidenc e (vridespread lowering of the ground surface) . This conclusion is `he same as that reached ,in the County General Plan (Asap 111-1, Butte County 1977)'. Loss, of mineral resources, field examination showed. ,no evidence of mineral deposits or said and gravel on the site. The Lovejoy Basalt is being tiseo as a source 61'crushed, rock, in a small' quarry to } Vl-propertyy , sated off the avisaccess rand about $DO ft south of the Little Chico Creek crossing. if use of this quarry is discontinued after the property is developed, alternative - sites can be developed upstreanij as the Lovejoy is, expos in canyon walls for about 3 mi north of the proptlrty boundary, F,lbbdinoi Little Chico Creek occupies a narrok^ steel?__;ialJed canyon in part of the Isom -Rall property; upstream and down- stream from this gap., slopes near the Creek channel are gentle. Slight lateral flooding might occur in these areas during the wet season. Clsewhere, tributary and gullc'h bottoms tri ll. carry water intarmittPntly during the winter It structures are kept out of uu.lch bottoms, and are set bads from Little Chico :reek 20 ft or so i flooding should not be a hazard. Erosion, The erosion hazard of` toomes soil is rated as "high by the sail Conservation Service (1961) based at lest in Part- on art on thr.: ' ,. moderate to steep slopes in the area, Lydon. page eight October 13, 1,981 is hi h in the atural conditions, erosion Y Activit, big Under n very lour in the LoveJoy soft sediments of the .hico Forma. n Formation. The lower Basalt, and low' to moderate on the rock redom nates, is more part of the Tuscan, where s(-2a %entary � er art. The upland susceptible to erosion than is the upP pa 2 have low erosion surfaces on Doe Mill Ridge ar=ct in �,�i 1/ activity. ' -be relative tions of development activity, under condisame, but erosion levels o� erosion act vitiy shoulshouid�increase: in all areas ,F -tcept the love}ok max' g -proper Eros `on fir` iv ty can be W�itiga11 ted by fa llo4i p h � • t�:on p ractic e . This inc luo eS us c a f .low design and G y � t'ruc ..sposa 1. ^uis, groper «riding, and ad�zate .water-car��*�hg and, di ct r ads, prompt re�*egetation ;of eonstrtnion sites ,. features on ' d adeauate compaction of fill rr«ateria ds ift the a analvsi s or volcanic ., gerneral.zed. .. �lolcansm. _ ai cites hat the sits might?' ,� ~i�zllirieau.- 3-9'76) it g „ �■ united s La �.eseof ash from a lar e ,.o S to 20 cm 2 to 1.. inches) L . G „ large" eruption would be subject �, ar eruption in the Laspen peak area• u is about fotir times as much material as was, erupted t erupts r p ,, ro. bi I' ty one tha ' e play 19$0 erupt' Of Z«ft. Zt. helms. 'TlelotT, be-Cause h affect the site is verb thy•- such an event Will tion, unusual �n 2tse]L, c'o` k it would require that a ] argo ertap ' incide With unusual Niue-raor tY high-l-, �el �9 nds Hazards that-_gajht loose siart�.fnt oroz-lea s 1 behavior of Toome$ soil is classed E: n81ve' sem' shrs nk-, lrel on �,. _ S That o � clay , �l t�c�nser�atit�n �erv�.'�e 1.96 r3- s so 1 as IOW ,oil On the upiw-d ridge #the the Chico rorr,;�'tion should �e ha gh• Y �.Y�'inkage stacks Bred :ressnce of soil mounds and, rarer watt P foil u _ • � tY is mod`era t �' in mol indicate that srr�nk,�s,rell activity to b so thin that on the Lovejoy is Clayey xn 'places , b ' �l c�'pao�ty ls, immaterial, its shrink-5t+e = t,nndti.ons, ivo 8011' can cause damage t o b�xildin pan$g utility connections . andslab driVOWaYs pit gat Cans 'that. can Lydon page nine October 13, '1981 can be employed include chemical treatment,' of soil at building tions below the 'so�lslevefoundati ons, placement of deep ;�ounda- sites, avoidance of 1. at; which expansion occurs, arra use of. grading and landscaping practices designed to minimize shrink- swell activity, ' vault. displacement. There is no evidence of an active fault on the site: However, as described in. the section on geology, some of the lineaments visible on air photos are probably faults; further, although the age of the last fault activity in tete linearnent zone is not known, the possibility exists that it is recent enough ,.or`" the lineaments to be- viewed with some-,co,ncern. A mitigation that can be employed to remove any possibility of hazard from fau.,lt displacement is simply not to place inhabit- ed structures, across any of thelinerntietts Degradation of water gjjalty Leach fields that rail commonly result in degrading the quality of surface or subsurface water. The Soil , conservation Service �l'3tr7� classes "T'oomensoil as having '"'severe limitation" in use nor septic-tank filter fields, severe-limitation rating means that the percolation rate is slower than 75 minutes per inch, and the l hely occurrence -of` an overflow greater, than 48 hr in duration is once in 5 years. `hese assumptions underlie ti-ds J�ating;s 1,2 inches or more of earth corer overthe leach litres; lines arc 4 inches or more :in diameter; and at least 2 inches of filter material covers the lines, and at least 12 inches is bel.oiw. them. The poor ra tine given Tootnes soil is probably due it part to its shallow average depth and the Fact that it tends to be mainly on moderate to steep slopes. Jiokever, where slopes are lov, and soil thic'Rnoss is above average, tht severe limi to ion rati.ig, might not apply. On the Uplands, soil is too sha.11.ov for leach. fields "i h scatterod spats, but in most placos dop'th appears to be adequate. Permeability is probably low to trwd+orate. Noir on the Lovejoy eLasalt 18 mostly, too shallow .for leach Melds, and is underlain Lydon page ten . October 13, 1981 if by a, rock type that is either impermeable or, fractured sufficiently, lacks absorptive capacity. Soil derived from the Chico Formation probably is unsuitable 1"or leach fields because of its high clay content. mitigations that can be used in soils that are only marginal.- ly suitable for leach fields include using greater length of leach, pipe than otherwise would be done; excavation of the lea -.h field to a greater depth than assumed by the Soil Conservation Service criteria, and, if nec.�ssary, use of imported fill to improve filtration characteristics. Landslides and rock -A alts. The County General Plan rates the relative risk. from landslides on the site as "moderate". EX amination of low --level air photos, and coverage of most of the _ property on the ground, fal:l- ' ed to reveal. any evidence of land- slides. : Lydon e eleven October 13, 1981 this spot, t= ie blocks fell, many year's ago, from lager of ITillz - flow material Just uphill. The blocks ,are stable now, grit: erosion of the flat_bench in sruture years might r_aus� them ,to roll downhill. The southerly spot is occuP ed by a lame flat: dock, resting near the crest cif a sm 11 ridge. it appears to be stable in its 'PrOsent position, and tha 81apes downl!ill: , rorci are not as, steep lierly as at the nort blocks. Edges o� ;lits in the: Lovejoy Basalt should be regarded as generally a SU:lblp wi,-h respect to rockfalls, because the rock tYpicallY is CrosscUt by numerous sriall fractures. - X1:..7. gat Ions i+k�.Y sail �5E? Mi- IL-,j� t used to rC-Iuce 7!yy rd from <'i r y Gf �,k vl 1. L�LJ 11 rockfalls o a include: (1) rot 'buil-Oing d:lvellings at the base or neer tip edge of bluffs in -,uscan the and Lova jQy esnoccia lly cs':ere erosion has begun to undercut the bluff and (2) avoiding, areas dozy-1i- slope from, tho large blockq deF ::°ibed earlier, or below any other Largo blocks that rtight later be dtst;o N2rc�d art tquaYe !�tctiviZ I. A pritLary effect of an eart'lquakq is K oiAnd shad. nc he horizontal to 1 w "_ . , � w and vortical vibrG:tion o:. the around that cart in resu.l y damacre' to bui l,c3I as) plpes, storage an s , etc . .1s cond dry effects .include liquey ac tion, lurching! Slumping y aNd rockfall. L gtiefac+-ioni +dr'T].C.�"ti car, bl:? a prob-tem in loose, granular. sa ',:Lura 4ed st) j 9 ref ors .Lt7 creation, of a liquid-like ;onditiorn in Soil by vibration. Lurchinq and p a, eluir,itlwhich a � m _ re most 5c�x ere -r'1 0680'; grztaulaY soil r rem e:rs to Zorr;,ation ot�-' rrounti�� diep:Ye:.Sions and large Ctac' ks by vibe,,-, mon, ?locks o4- rock t r t arc on t'fall ir o ari? tim.0s sha)hen looso apr~inq an c�:r°thanako, e,at�se tl`i loom; iii y, clad; -fr'ou t -S r>` soil m 4 , 5?t1bj1`' t 1.jgj.t!z c, i oa k ► 4�Lk"�i ric , -i net E.Ititr1 rC cr :AR ru, rice `�rG'Se,,nt,I yt', csri t..h %1 sy tt� .,(,t'::%:i` _pt prr haps J r'tc:ac„ i14t(AY, Lllono ill-Lormi l..tent o A. rJ do YtOtt,� 4Wonstitu L- yV.al1.��'ii 0" t 110 flli d�.�:'�., "Ibi-kAra ll Cot. d' i.Yo ,a probl Es i in places") aces) M t:icration ►r���atrc.� t�� e�z+il��rr�lie��n�.u���� �tw�c�fal; Lho scr't ci aS drjsCr,'jLF d ill t 1to*ct ori 0YI landslides anc1 Lydon nage twelve October, 13 1981 The sevrift y of round shahin depends mainly on the distance 9 � e to the causative car`ttiquai1e., the Strength o-1 the earthquake and the nature of the soil and rock at then affected, site. Tbo ' st.rengt'- of earthquakes is expressed as mac;nitude (pichter ale) scale) and the severity of damage in inhabited atr�as is express- i ed as intensity (Moda fled Xercalli scale) Si(ini4icanIt earthquakes within about 27 mi of the site in- clude one of r, (magi itud,e) 15,7 .near S.4-irling +,lity in 1940, �t 4.6 north o SidVe-11, Park ea�St of Chico in 1966, and �-I 5, 7 at pa:l.erwo a in 1975. in addition, earthquakes ha:viug an intensity oZ VI at 'their b g - rred in 19^2 east of ,�oarc� (arta aiitude�out�hrofop�da.�ec( - M1 Stirling City and 194. Deal of al, 1978, Div.. h ' Geology- 1978) Mines and [Pa aphrasing part of the �,odified Mercalli Scales :vea p y= adobe crack; w' ws V1: k faster and unreitt�oYced breakndo . VIS: r,eak masonry dataaged,• some cracks in good but u'nreinforcw- ed masonry. VIT1 S food, belt unrf3ln'forco d masonry damaged Some damage to relft orced structures with good mortar and worktr.anship; loose panel �.alls throur—n out: Several smaller earthquakes within 5 mi othe site, mainly I! to the east, occurred following the 197 orovilio earthquake j (MarkS atld 1n i t-191/8), While not sigrii iir+ant in t rt»s of f damage), they Yhdicat-e that the zone of lineaments wiEhin which the site 1iea is an area of otigoinq soisraio actdxity. An inforr� ,, fault~' shoirm on Mar It-I 'oma the County 31enoral Flan Y.S., the Satre aka the linoaxm,Ont that ext.,mcis south� ,,*ost Prot, the c4entiwlr �Jf Lhe north la.t34.... of 3cc+ 13. :. t,ecause the site dies, within tbt--i northorrz of the, vooLhill. ucat.tlt ,system, and boc* iw�-n tho kiySten, is gbnerally :OnsidorF•A capahlw o'r a aaGaa tatdr tJ x Fj earthtl>`sa'eLovztl. eriC�e' tel tcYror sy inj'y� ' and public :studiosy� ifrrk)ta yiyysy �(s�ttmwari2�e ypytilVatto Divi • y I-flos a rld ���5\.+."logy - a f 1 19 o! ]. j i t. is �L�.oa sMJF a 1 to plann.L�7�,. ly.� J' expec L the site to be stabjtx. Led to a oarthquak Lydon page thirteorz October 13 1981 wth its epicentex (a spot on the ground i *lediatcly above the earthquake source) Iocated at a distance of less than 20 Studies correlating magnitude, distance to epicenter, and effects at a site (Boone et a1. 1978) show that such an e'arth.- i quake 10 mi from the site could result in horizontal ground acceleration of 0.2 to 0.4 q (20 to 40 percent of the Accelera- tion ai gravi'tY) "phis cot-respc�nds 'werl.° rOughl�� to an intensity Of WII1 (Hays 19$0) . This t e Yp Of la feral motion can be mitigated %n structures Dy following the design criteria .; the uniform Building erode, which identifies all of northern California as being in seismic zone 3 (earthquake intensities o� �Il or higher anticipated); R RF'LR:,...,C Z, Snore, D.111-1. , et al., 1978, 88timation o=4 ground motion parameters t.S, GeOl. 5ul-vey Circular 795, 43 p. Hutto Count 197/7, z inal Sutte' County General Plan. jaunty 1 Pannzne t ; unptiblished Sec . 11, 3 oismic sa f etv etc- ment 23 p.; .�Ec, lZl : _ a.fety element, 23, p� i7cpt. ©f 'rater Re5oi2YCC_+ , 1979'`the .iugtls"t 7. 1975r ov Otil.le earthqual�e investigations: Ca 2a x De- ::'ater resources Bull. 203-78, 669 p ' div. of Mines and. �ec1gy, 1978, rarthauake catalocue of Cali=— map by Real et al. pja7$. K compiling 04 data Liu ornia • to 7et�,c—+.a corn latiCJ21 Wed In Coil 1 1li�t♦ of i:ines and Geology '~?tta, if; 1979, LTi echilica l review- of the seismic safety :f the Auburn damsi-Le*. <t �■ . ,�. .Ines and Geology pet . Pub. 54, 17 p Aarwood, D,S. , et a1. , 1981, Ge logic reap of the Ghico mono- Cline and nnrthea,stcrn part of the Sacramento %valley, california: t .S, Gebi.ury y Map ap I�1-23 , scale 1:62 # 11) mays, ;F: r� . , 1930, Procedures for estimatinq earthquake ground mo ions, u.j. Geo'I. . .lurvey Rrof. I -aper 111.4, 71 p ma rks e:X , and Lindh, ,a.t"r.. 1973 , • Pegional oism�.ci dL the i �ierra. foothills 11 the Wein- by Ci OtOV-file, Califol. Buxi. isrs:olog icaI Soc: a,f .°' tiler. Vol. 03,, p, 110 -1115; :�ttllincau:, , Li j 19176 , 3•'relitninaxy sere+ Map Of volcanic hazards, in the 48 CantarMlftous United States: VIS, ileal. Survoy Xap x'!i"- 7$ , Neale 10)500)000, Lydon. P g e fourteen October ;13, 1981 Earthu.ake epicenter map of California: Real,p. , et a]`. , X1973., _ q I� 39, scale 1:11000.0000. Cali, . Div. :yIines and Geology ,_.ap Sheet soil ma�sj Soil_ yonservation service, 1967, Report and general Ti.S. Dept. ,agriculture, 33 p. plus Bt�:e County;, Cali BuPendices; scale 1:125,000. ap map 'I t. Ljhi lxp Lydon California ;registered Geologist 144 at -I% --ached.: Map-- Geology o an area along Little, Chico Creek and Doe ,till Ridge i • EXOLANATIONT, scan Fot- IKi t iori f � p ern , � �. •w� Y � � At � ;�,. �♦ .� // �l s. ��.:,"�k�3r'.�,'Yr': .r �^�p .,,''� 1.�.i.> } L Laveov Basalt OF A, v G C' "Co Formation � � - • bra '' w a ' ,is IAi4G L;'r"Ts ..8 cY?Co ,,Jt'�t2n`la,. bFst-w"eE"tl . r . •�: S� + �r>/i a; �', .i/,% • + CREU, AND Dot m, t �-• f �i rock ons lUs; dashers •,rr' where obscured wracttres vislal e on �•: ° .-� ,„._} -: tf !, ra Chi r hotos:.►Gis -1Q'. ...vim y `e ate„` " '.' �» ; T7�.+!' khere taken from H " A a rv:Uod e a 1. 1981, H '. � �, r .yam "... �` .. .f sir �, },t ;� I .�+ i'�' aJ•� - N" . property boundary f Fj Socatson appr--,)xitnate + x t "w r, e" .. �� > /�� `fir ✓j I + -,... i'� !r ' ' , ... � /�'_'���'','✓ L �� = �,r.-.�.' ` t f . ..t .s..-._, .--� 1. tiTlp.�� , �H..s . � * `.r•'i ""''�,.it""^� :=-r''r-! - ' i � � *r�``�.�„y. ;C r y k q w.�+"'r • t �..�✓ C � . Y6i1l � ✓ �r. � �� �l' w .�✓ i' ^'h.}j i ,w k k'�`'� �✓ o ,} �•�-�-�� Pt, A. LYDON � ��� { d . /�� *1 rpt "` ��:, �' �. ° ,� �r �. �`�.{_r�,✓ � t. . � �` f � _ S' � � � d� � � .. , • � �.. ' >r..•J" l _ r `s`'---"'� Ji, y. .....,.1, �,+ti i � b'�'!� ...v , wu rr .,✓ r � ,�.. ° r, 1+��� ��.a , . r .L � - .» ... —� •tom ;y .y `, � 1. .rl.. rte, 41 + ry / s'f { scale., f t yya • ��'y ' 1 t > ( +F,` , �•.......-r" +} R,•�aZ'„'-.,;:. ..•.,,�- .,u.. a.,.e.•w., r � k �I A r p r �+ ... }'.",+' 'J,�'r• � ✓' i� f y, , i �+"' � rY ;>. f�y,t;' � Via+ ��.yi,,t�t,," 'w,'�t+•'�'" .,.,�,+'r''� >, � i "�....,<.. '" � {.'' `w.,.�. 'r, %''. r� J r�Yi a'^_'> .+�1',� �r';> ✓�� ' _ �t..;Y `+�"`": "' > /f '> . jit.� !''y f r' APPENDIX C JON M. ANDERSON CONSULTING' CIVIL £NOINCEK :960 MYRTLE AVCHUC `i ELEPNONE 1916.1 343.7396 CHICO, CALIFORh11A 9s924 22 October 1981. Department of public Works county of Butte County Center Oroville,Califo°rniae 95965 A 1TN: Mr. John 114endonsa Subject:, PRELIMINARY SOILS REPORT= page 2 utilited to formulate recommendations of this study. The surficial geology of this property is mapped as being Pliocence extrusive. volcanics of the Tuscan formation. This formation is a relatively undeformed structural member (a homocline, generally dipping 19- 20 westerly) and typically, consists of consolidated pyroclastics, mud -flow breccias,`tuff breccias and various intervolcanic sedimentary rocks. The surface and near -surface geology of these lards predominantly consists of pyroclastic materials that conformably overlie andesitic rock nt relatively shallow depths., soils in the� ro ect area, w=here developed, typically consist of P residual or intervol.canic soils belonging to either the Toomes, Supan,,, or Stover agronometric series: Additionally, some isolated occurences of the Cobleigh series could be expected. Generalized properties typical of each series for this area are: Toomes Series - Generally a gravelly -loam surface and subsurface soil with a stony surface layer. Depths are variable from 4 - 20 inches in general. They exhibit moderate permeability, a slight erosion potential, are well drained and originated from "volcanic breccia parent materials; Supan Series - Generally a cobbly--loam surface soil with a cobblvclay subsurface soil. Depths range from 20 40 inches in general. They exhibit moderately -low permeability, a moderate erosion potential., are° well drained and originated from ,Ultramafic volcanic rOck materials; Stover Series - Generally a cobY ly-gravel:ly loam surface soil with a cobbly- gravelly clay subsoil. They -`exhibit thicknesses ranging from, 20 - 40 inches in general, have moderate permeability, a moderate erosive potential, are well drained and were derived; from ultr„«afic volcanic- rock parent materials;Cobleigh ” Generall Sa stony gr f avell loam-sUr.-ace soi"1 with a clayey Generally y v� subsoil. Depths range from 40 60 inches in general. They exhi page 3 Rock exposures generally conform with the 10-20 westerly dip or have had outcrops exposed by fluvial processes. These exposures are generally limited to the bluff areas and are typically gray - hued pyroclastic tuff breccas consisting of andesitic and cinder fragments incorporated within a welded -ash or mudflow matrix. Very minor, 'if any, residual soil has developed on these relatively young extrusive rocks. The safety and seismic -safety elements of the 'Butte County General Plan indicate that: 1. This project is adjacent to the location of an inferred fault of unknown activity. It is also located about four miles from a historical earthquake epicenter of. 4.0' to 4.9 Richter Magnitude; 2. The liquefaction potential of these soils is generally low; 3. This project is not within a potential subsidence area, 4. The landslide potential of this area is low' to moderate; Si The erosion potential of these sols is high; 6. These soils 'exhibit a low potential for expansiveness. In view of this reconnaissance and available information, the following limitations should be implemented (in lieu of special site -Specific investigations) to insure the establishment of structurally -sound residential building foundation Ii Construction should—be limited to areas of less than 25 slope; 2. Building 'foundations should not be -established partially' on soil and partially on rock„ 3. Foundations should not. encroach on upper -bluff areas (within 18 feet) and should not be located downslope of near -vertical blvffs; 4. Foundations should not be developed on fracture lineaments faults or joints,) pursuant to recommendations in the geological -hazards report P.A. Lydon, 1981). The locations of these lineameri`ICs are shown on the enclo8od map (see Appendix 3); S. Slab foundations shokxld be excluded unless they are total - founded on massive bedrock. Although such foundations taou]d probably prove to be satisfactory in; most instances within the project area, current indeterminant circUinstan- ces (eg; undiscovered surface exposures of clay deposits;' site -grading operatiohs that could potentially remove the loamier surface soils,,' exposing clayier subsoilmaterials, and the wide range of indiv�.idual sites available for build- �.n g locations) nede5slttte this exclusion to avoid a moderate potential: for expansive -soil conditions. APPENDIX 1 j D N M. ANDERSON T OONSULTINO r -ML CNQINCCA - - 960 MYRTIL AVENUE. TELEPFjONE (91G/7t.3 •7396 CHICQ• CALIFORNIA 95926 �x gni a` EXPLORATORY EXCAVATION 'LOG i File No. • w -i f_. Pe W . ' Location: DatetP"T X81 Logged Hole No. By: _Ni�. -- ,- r core pit trench qodcuchannel banI. TYPc• auger Excavation •• drill & typeer i Slope: 1�,# ? i -�— **ie****�*** •►c�**�ir�****its*'ir*�cir�Ir�cic#�*irk*9r ,, Depth Thickness `*in °C Classification & Description feet e W , x _ f� 4 ; M �..�.--------- - �' I p�T�' G -t R.l�.�l.•-.'tom , ' �t,. S , 1 ai > -' • Y , "� -+'� � � � ✓11.1 ���•+ �.�`• °;, �. ', a q � 1 dad � �r�,• k G 01 �'J „ n W • t i d i+, �ry tal 45 • � REMARKS . • at. Jed*' a;1 ? .. .+. ;wafC:l��14'��Q/�� �Z•i:.1'� C3 rf lGAi _Lo �J•���L±.•��j�1 X�so .T .M N JON K ANDERSON f:, ''• `- - CONS%ULTIND CIVIL CN61NCCq. .. 968. MYHT(_C AVCNUC. YCLCPHONC WIG) 343.7396 CHICO, CALIFORNIA 95926 "'. EXPLORA'T'ORY EXCAVATION LOG •,*�Nt��r�irir•k�cir*�Ie***�e•kie�ir�es��c�rit9t�e�trot�r4rYr*�r*ir9r�t�r�k7le�e*4r�.i•�tk�ir°s'rle:t�**�Y�r4r�fr��t�k�e°ie*rir**�Y*7k •, -Project: _�C ,1L-1— File No.: s Location: Date: Logged By: _L Hole. No. -n"- ! Ekca.'vation Types augev core pit trench roadcut channel bank drili & type other Vln�CT16. _ O.G. Elev.:,_I F'^T" Slope: : r`"8'si !s,� e .'i4'�•� sk 4e * * �c �k * Ik sir �t * sk �r it �k'C •i; it �c y' yh �t' �Y yt 71r 9: �r �t pk pie * yr * fir• �e Yr k * * it � �k �Ic ie � �t �r �• �Y �r �c � Slc it yY ;Ir * �e Slr it * * ;h sY * afr �c fe �r a4� t{F'Depth Thickness - � rom f to in feet ° CC Classification & Descriotion .y A bre• p ��..,.. . �. *� a z r A �n w } r 9 n Put�.,y I x .�..�.r..r� rte SLi�,Q16.L� �• �..��iijl..��L.cYY���ii�1�71:�i�1=� �IV� -.�' B 44 w } q i r ... s{ Total 4 111S,r . t � i"moi—e. � f i t ” t• 1 `� � � 1�- /�1 G��R '��"sj x... �y� G/ �_ � rrwrr� �44 /`[�.�n y �� •� '„k+ s i �...r� a. x