Biological Services Program FWS/088-80/09 1980 ~ 0 ,...... ,...... ,...... co _C') Ul :::; T""" ~-0 0 l.C) ,l...C...). GRAVEL REMOVAL ~ GUIDELINES MANUAL FOR ARCTIC AND SUBARCTIC FLOODPLAINS Environment Research and Development Program ~CHAND DEVELOPMENT rAL PROTECTION AGENCY j Fish and Wildlife Service U.S. Department of the Interior The Biological Services Program was established within the U.S. Fish and Wildlife Service to supply scientific informa tion and methodologies on key environmental issues that im pact fish and wildlife resources and their supporting ecosystems. Projects have been initiated in the following areas: coal extraction and conversion; power plants; mineral development; water resource analysis, including stream alterations and western water allocation; coastal ecosystems and Outer Con tinental Shelf development; National Wetland Inventory; habitat classification and evaluation; inventory and data management systems; and information management. The Biological Services Program consists of the Office of Biological Services in Washington, D.C., which is responsible for overall planning and management; National Teams, which provide the Program's central scientific and technical exper tise and arrange for development of information and technology by contracting with States, universities, consulting firms, and others; Regional Teams, which provide local exper tise and are an important link between the National Teams and the problems at the operating level; and staff at certain Fish and Wildlife Service research facilities, who conduct in-house research studies. ARLIS Alaska Resources Library & Information Services Library Building, Suite 111 3211 Providence Drive Anchorage, AK 99508-4614 FWS/088-80/0a Q.l June 1980 5¢0 .u~ ?IJ/tJ9 ,/10 I GRAVEL REMOVAL GUIDELINES MANUAL FOR ARCTIC AND SUBARCTIC FLOODPLAINS U.S. FISH AND WILDLIFE SERVICE by Woodward Clyde Consultants 4791 Business Park Blvd., Suite 1, Anchorage, Alaska 99503 Principal Authors M.A. Joyce L.A. Rundquist L.L. Moulton With Input From R.W. Firth, Jr. E.H. Follmann en Contract Number .<Eu!) FWS-14-16-0008-970 <!) r/1 - This study was funded .!:s - ~ Interagenciny pEanret rbgyy -tEhen vironment ~Ero - ..ll-J .ll~J \'".10 t2·50~ 0,,(,(......'..0. I...___) UOR.Seff.s icEeean rvocifhr oR anenmsdee Danrtecavhl e Palonropdtm eDecetnivote nPlo rAopggmeraenmncty r~~~~"J~"'"J'-.< c,J·E.;a(.s->..l l ,r:··c/o:=;1»:o;i : l l ·.;~<g.2-;g!): . '0~8<"O".,\." .J ' ) 00T" " Performed for the I~Zl ~'"~"'-..--50 I!) Water Resources Analysis Project :0: >.·..-l <!: I,..!..)_ Office of Biological Services ~ ('I) U.S. Department of the Interior ~ ('I) Washington, DC 20240 ~ DISCLAIMER The opinions, findings, conclusions, or recommendations expressed in this report are those of the authors and qo not reflect the views of the Office of Biological Services, Fish and Wild life Service or the Office of Research and Development, U.S. Environmental Protection Agency. INTRODUCTION A study was initiated in mid-1975 to evaluate the effects of gravel removal from arctic and subarctic floodplains in Alaska. The primary purpose of the project was to provide an information base to assist 'resource man agers in formulating recommendations that would minimize detrimental environ mental effects of gravel removal from floodplain material sites. To achieve this objective 25 material sites were studied by a team of scientists and engineers. Three major products resulted from the study. They are: (I l a Technical Report presenting synthesis and evaluation of the data collected at the sites, (2) a Guide I ines Manual that aids the user in developing plans and operating material sites to minimize environmental effects, and !3) a Data Base filed with the U. S. Fish and Wildlife Service in Anchorage con taining raw and reduced data, aerial and ground photographs, and other relevant material from each site. This report is the Guide I ines Manual. APPLICABILITY OF THE GUIDELINES It is important to recognize that the guide! ines contained in this manual were developed from a study of 25 floodplain material sites in arctic and subarctic Alaska. Therefore, they deal neither generally nor specifi cally with material sites in upland or coastal situations. Similarly, they do not include evaluation of the relative acceptabi I ity of uti I izing an existing active or abandoned material site or an abandoned structure contain ing gravel lsuch as a dri I I pad or airstrip! rather than a floodplain site. This should not be interpreted as recommending sites in floodplains over other locations. WHEN A NEED FOR GRAVEL HAS BEEN IDENTIFIED, ALL ALTERNA TIVES SHOULD BE CONSIDERED. ONLY AFTER A FLOODPLAIN HAS BEEN SELECTED FOR THE PROPOSED MATERIAL SITE DO THE GUIDELINES CONTAINED HEREIN BECOME APPLI- CABLE. However, if used cautiously some guide I ines may be uti I ized in other site and regional situations. The 25 material sites exhibited a range of variation in site age, gravel mining method and location; and river configuration, origin, and size. Selected sites were minimally affected by complicating factors such as nearby bridges, culverts, vi II ages, and other material sites. The latter case is significant in the application of these guide I ines. On large proj ects it is sometimes necessary to locate a series of material sites in close proximity along the floodplain of a river. The effects of multiple material sites in a floodplain were not evaluated in this study. Hence the appl i cation of these guidelines to multiple site projects must recognize this shortcoming. The user should be thoroughly fami I iar with the contents of the Techni cal Report to give perspective to the guide I ines for their effective use. THE GUIDELINES ARE DESIGNED TO DIRECT THE PROCESS OF IDENTIFYING, PLANNING, PREPARING, OPERATING, AND CLOSING MATERIAL SITES; THEY ARE NOT MEANT TO BE USED AS STIPULATIONS TO BE USED IN EACH AND EVERY CASE. It is essential that the user of these guide I ines consider each materi al site individually. Identification of unique characteristics may require that certain guidelines be ignored or interpreted differently, or different combinations of guide I ines be considered. This manual is intended for use by all individuals interested in floodplain gravel removal. GRAVEL REMOVAL METHODS AND CLASSIFICATION A variety of gravel removal methods and river characteristics are covered by this manual. In general, these methods and river characteristics consist of: I. Scraping exposed or vegetated gravel from active and inactive flood plain and terrace deposits. Scraping usually does not involve work ing in active channels. 2. Pit excavation of vegetated gravel deposits located in inactive floodplains and terraces. 3. Dredging from the bed of active channels of large and medium-sized rivers. 2 SUMMARY OF PROJECT RESULTS AND CONCLUSIONS Study of 25 floodplain material sites has shown that disturbance result ing from gravel removal operations can be minimized. Two gravel mining tech niques were used at the study sites, scraping of surface or near-surface deposits and pit excavation of deep deposits. In general, approaches to minimize environmental changes caused by scraping included maintaining buffers between active channels and the work area and avoiding: • I nstream work • Mining to depths and in locations that induce permanent channel shifts or ponding of water • Clearing of riparian vegetation • Disturbance to natural banks Large rivers and braided rivers generally provide the most accessible gravels for scraping. Gravel mining using scraping technqiues in these areas frequently resulted in the least environmental changes. Pit excavations resulted in permanent loss of terrestrial riparian habi tat, however, many pits increased local habitat diversity. These newly created habitats frequently received concentrated uti I ization by local fauna, particularly fish, waterfowl, shorebirds, and furbearers. Large quantities of material were excavated using pit mining techniques. Pits that were located on the inactive side of the floodplain, and were separated by vegetated buffers in the range of 50 to 100m, generally did not influence active channel hydraulics. Pits were found to be most beneficial to local fauna when they exhib ited the following characteristics: 3 • 2 ha or more in size • Contained diverse shore I ine configuration • Contained diverse water depths • Contained islands • Contained an outlet connected to active channels 4 PROCEDURES FOR GUIDELINE USE To use this manual it is necessary to acquire information on site loca tion, operation, and environmental conditions. The information consists of descriptions of the site and gravel removal methods that wi II allow predic tion of floodplain changes. The manual is divided into seven sections based primarily on the order in which a site wi I I be selected, reviewed, and worked !Figure I I. Although site selection is the primary topic of Section I, much of the information in the other sections is also valuable in selecting appropriate mining locations and methods. For this reason, the entire manual should be read and clearly understood before deciding on a final work plan. For ~xample, much of the information in Section VI; SITE OPERATION can be valuable in determining where selection of a specific method or location may increase the amount of avai I able material while decreasing environmental alteration. After the guide! ines have been thoroughly reviewed, it is recommended the sequence presented below should be followed. SITE APPLICANT I. Identify suitable sites using the procedures described in Section I. 2. Develop a tentative plan on how and where to remove the required gravel within the proposed site. Acquire field data needed to complete Site Planning as described in Section II. 3. Evaluate the proposed plan by applying the appropriate guide I ines from the SITE PREPARATION, SITE OPERATION, and SITE CLOSURE Sections. This may identify alternative methods or locations and potential problems, speed the review process, and lead to more efficient site operation. 4. Develop a formal Work Plan, as described in Section I I I, to be sub mitted to the appropriate agency. 5 Problem MATERIAL NEED Generll Sit• Selection IDENTIFICATION OF SUITABLE SITES I I Section I I I I I I I I I I I .,.I e 1 0. 0. :J! 'C Fk:Jodplain c;. .... ~- GR.u.ei.md..eo.lw.in.l ln gcl I .111 WORK PLAN DEVELOPMENT ]I Section Ill E I I submit _ .,!P.£!0.!!:11_ __ 1 I I i SITE PREPARATION -~-~-e;-;c,y--S-i~ - SectionV I Visits I I I 1 1_ ___ -f-----'S~I~T=E~O~P=E'-'R!"A':'T._,IO"-'N'------I Section VI : _____ ...1·----~S~IT~E:..:C~L~O,s..,u.,R._,E,__ ___ Section VII Figure I. Gravel mining planning and implementation. 6
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