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Home My WebLink AboutDRB130159 REV1 Debris Flow Hazard Report.pdf . _�' L'. . _�i . I �i . . � �� limoi I �� iui.�, 6�IoniJo.vlo01 f'Fe�ne: )��' �i-�� l�),}i HEPWORTH-PAWLAK GEOTECHNICAL F,� y�� ,�; y�;� �� I� i�,, ,,�„i,i�,� � � �� May 22, 2013 Triumph Development Atm: Mike rosier 12 Vail Road, Suite 400 Vail, Colorado 81657 inctbs�er�(i�?�,il�u��._coi�i Job No. I 13 048B Subject: Debris Flow Hazard Review, Proposed Noell Residencc, Lot 6, Spraddle Creek Estates, 1000 Spraddle Creek Road, Vail, Colorado Gentlemen: As requested, we have reviewed the debris flow potential hazard for the proposed Noell residence at the subject site. The purpose of our review was to evaluate if the proposed residence is exposed to a debris flow hazu•d and is an addendum to our rockfall hazards review report for the project dated April 30, 2013, under the above job number. Summary of Findings: Our field observations and literature review indicate that the proposed residence on Lot 6 is not exposed to a debris flow hazard risk. Scope of Study: A field reconnaissance ofthe project area was made on May 19, 2013. In addition we have looked at aerial photographs, detailed topogaphic inaps and published regional debris flow information by Town of Vail (2000). This report summarizes our field observations and presents our findings regarding the debris flow hazard potential at the site. The study is supplemental to our previous proposal for professional services with Triumph Development dated Deceinber 21, 2012. Hepworth-Pawlak Geotechnical previously perfonned a subsoil study for foundation design of the proposed residence at the site and submitted om� fmdings in a report dated April 15, 2013, Job No. 112 048A. Site Conditions: Spraddle Creek Estates is located on the south-facing Gore Creek valley side just to the north ofthe Vail town center as shown on Figure 1. The general Parker 303-841-7119 • Colora�loSprinhs 7�y-633-556Z • Silverrhorn� 970-�}68-I)ti) Triumph Development May 22, 2013 Page 2 topography in the project area is shown on Figure 2. The lots aze located on a hillside bench and average slope ofthe bench across the proposed building site on Lot 6 is around 40% down to the south. This average 40% hillside slope continues uphill of Lot 6 to the north. About 300 to 400 feet west of Lot 6 is Spraddle Creek, a fairly well incised drainage. Spraddle Creek Road is located to the north of the proposed building site and construction of the road has required several retaining walls to limit hillside disturbance. Native vegetation in the area is mostly grass, sage brush and other brush with some aspen trees. The existing retaining walls and revegetated cut slope uphill ofthe proposed building site appear to be perfornung satisfactorily with respect to erosion and global stability. Field Observations: The steep hillside bench at Spraddle Creek Estates is underlain by glacial till deposited by valley glaciers that occupied this part ofthe Gore Creek valley during the middle Pleistocene-age Bull Lake and late Pleistocene-age Pinedale glaciations (Kellogg, 2003). The Bull Lake glaciation occurred between about 132 and 302 thousand years ago and the Pinedale glaciation occurred between about 10 and 35 thousand years ago. The glacial till consists of subrounded, gravel- to lazge boulder-size rocks in a sandy loam soil matrix. The glacial till has had a relatively stable, recent geologic past and landslides or potentially unstable slopes that could produce debris flow material are not present in the azea of Lot 6. The existing road cuts uphill ofthe proposed building site on Lot 6 aze revegetated and erosionally stable. The existing road cuts should not be a potential source of debris flow that could reach the proposed building site on Lot 6. Regional Debris Flow Information: The regional debris flow map by Town of Vail (2000) indicates a medium severity debris flow potential area that crosses the eastern part of Lot 6 and extends through a narrow width in the central part of Spraddle Creek Estates. The debris flow risk designation may be from a debris avalanche risk due to the locaily very steep hillside in this azea, but based on our site specific review, in our opinion, Lot 6 is not in a debris flow (or debris avalanche) hazard area. Limitations: This study was conducted according to generally accepted engineering geology principles and practices in this area, at this time. We make no warranty either express or implied. The information presented in this report is based on our field observations. This report has been prepared exclusively for our client to evaluate if the Job No. 113 048B GecPteCh Triumph Develop�nent May 22, 2013 Page 3 proposed residence is in a debris flow hazard area. Our scope of seivices for the cunent study is limited to debris flow hazard potential and does not include evaluation of any other geological hazards fhat inay be present in the area. We are not responsible for technical interpretations by others ofour information. IfUiere are questions, please contact us. Respectfully Submitted, HEPWORTH -P��`�{"� TECHNICAL, INC. �=�''��N:;ao'� j�<</y�s P �. ^K,J!�.�'V�` 1 s��✓ . F:.:.n e i�.,.tn � �l��a� '�cg�P" f., n.r S./ � Steven L. Pac6�.�ak`�,,F�./n/i��'� u �'F::`�'i,`.j;.�0?dF,t!,'s`�°ts� :��,:�t� �_.��- ��. Rev. by: DAY � `�` ��`�"-��"' ":ti,,��c;�-. SLP/ksw Attachments: Figure 1, Project Site Location Figure 2, Project Site Ma� cc: RMT Architects—Paul Miller (paul<ci)rmtaaarcl�itects coml Beck Building Company- Tom Solawetz (tom abeckbuilds.com) Monroe and Newell—Craig Can�oll (ccan•oll��inonroe-newelLcom) REFERENCES ICellogg K. S. and Others, 2003, Geology Map of'the T�ail East Quadrangle, Eagle County, Colorado: U. S. Geological Survey, Map MF-2375, Version 1.0. Town of Vail, 2000, Official Debris FlowHazard Map, Town of Vail. Prepared by the Town of Vail, Colorado (Adopted by the Town Council on October 17, 2000). Job No. I 13 048B VEC9tGCh . : , i._ � , , � . � : .! � � � - � � , � �.��- �� . . { . . � . � � � . . ..- ' - � � � _ � . I - ,.��µ. � - . � . � .. � �.�:�� , . � ' . � - I �i k . . .{e` t � � � ' � ��/i/1/iI .. . . _ . . I' . . . ' . .. . � ..11 . � i ' _ . . . _' _ '. i� �, �''� . .. . .. . .. � . . . .. . _ . _ . . " ` 'C.� i . . _ . I ... ' �T � � I . . . _ E k ` , ' " G d, y.>t,. Spraddle-Creek - - � .' ' ' `.+ir �.� � � F . - Estates � - � . i� G ,,,�,. ' , � . _ y�� r v �� l�+ a1�A!} �...� . . . e+"d� ai � G"i ..`�,3'h � ' _ ° � °" r'�,'� ��y �M�.�n� �Y a k �-C ' " . _ _ .... _ . �'r d �"�'M er � 11•� � Z,� - _ � �� ` � I � �f� �. :. _ . ' - ,' � 1 C°'� • . _ , �Y I �� .:� . - _ �� .e�� . - ._ � .� �.. .A � -= 43': -. . � _. -- - - - _ �� .� . . - _ .•, f r`'. W~ i�� . i iill � �„`,^4��1 � . .. .. .� •-• 'r�� . ' . . . • _ . � - r,; - - - - t .. d�e� ;. , �,<<.� : - - � � - . � - �p. ��. � -� — � -. . . '- -.- . �. �o' �- � - .�i� --`- _.-_ . . � - . . � , � . 4 � '- j �pG , . ��.r ��- � . . _- . � . __ D 5)- — � .— - � ' � _ . 5 T i � � � �S' �sN . � _ _ . � ' _ ��n �.. �I f � i` - � _ — ' - . '% - -'�. '_r,, __ ...},j� !. I , .. _ � 1 � _ `j , . k. . . � ��-c . . � n - - 19- � _ - 1 /, � l t � ' � . ''_ (''' f � � � '` _ , ;� '�yu `r. r � -�., i f � ` j . .i.-- . � . ' �I i . 4 ��. . . ° � I � � .. ' - _ _... � �' . . ' . �.ii�i7 .. .- .. - i � _ i yI I� . _ ' ., "�{ .�"� - � . .. _ - � � llr�l_ . � l'r a!� ' �A l �� 5 7 ��' 7•. �A��ildS�. _ ._ _ � . -. f �� . - . . � ..I 1' _ �i.l' i . � . - . - _ . � - . . , � .. . �� ' Explanation: � Lot6 � 2000 if. I 1 � Scale:1 in.=2000 it. Contour Interval=40 ft. May 2073 113 04$B �t�h Proposed Noell Residence I_ot 6 Spraddle Creek Estates `"POdp�""w`"';GEOTEpHN1ON� Project Site Location Figure 1 / ^`�,\ \�'`,\ \\ \ � \ _%� n�� ' , . / %i �' ' ! - - � � � � : -- ��t : � � . � ' �, �E � S �.'�- � p� _ �w _ k�� :�'� � � ^ .^eE �` rv i : . , . � :'. _. , .. .;t - - _ � � - ;ib _ ' - � _ Y \ — �_ \ `>` � � �-. � � ` ` ,1 � �1 �. � $I � _ ' ��\\ � , ��_� ; _ , , , � , � _ ' �,.: H�9hwaY/,� � � ��. . .. _ _.. � _: p , . , = : . . �—i � � hwa % �w�� e��9 :` _ , �� C6ast@ � - .. �. : ;. _� ; � ' ound ' � -, � � Explanation: � ... � � , ., :. .. ._ ....,, .. � ' �_ .. /'�;S Exisffnq Residences 'J /'�`3 Pr000sed Residence on Lot 6 �!d �� Topoqraphic Slooe 8 k• Prommani top— pgl�� SjoPe break along south side of valley side � 6ench. 250 ft. I I � Scale: 1 In. = 250 fi. Topographic infortnation from Town of Vail GIS Department Contour Interval: 2 ft. May 2013 113 048B C'-s�Pte� Proposed Noell Residence Lot 6 Spraddle Creek Estates HEPWpRTH�PAWLpKGEOTECHNICAL Project Site Map Figure 2