Trees & Tree Commission - Laserfiche WebLink

New Search

I T ree Preservation During construction Projects high visibility signs defining the need to h ,-� save the trees were posted on each tree. These signs were erected at low cost, and 4-44' y „. ,r = based upon our experience in the con - ' ,. _. % tract, served equally or better than the a i erection of snow fencing without the -w -- negative side effects of high cost, inconve- - - `: nience, and compromises to safety and ±�- maintenance of the area during con- --"- t struction. 4 �", - Another key element of the curb K , Y �r removal and replacement operation in �?r _ 1., volved root pruning of the trees one ft �, :-+ - behind the back of the curb. This was N''‘'. - ' done prior to excavation of the existing curb, utilizing a rubber tired trencher equipped with a mining chain cutter capable of providing a smooth, clean cut • YELLOW "Save Tree" sign wams workers not to pile materials or capable the root system. The advance oth cutting dig within three feet. The signs and worker education were effective. eliminated the ripping and pulling action normally inflicted upon the roots during ROBERT J. KOZUREK, P.E. The project included removal and excavation. This method allowed clean Construction Division Manager, replacement of the existing curb and gut- removal of the curb and permitted the Department of Public Works, ter along both sides of the streets, trenched soil to remain adjacent to the Naperville, Illinois reconstruction of drainage appurte- severed root ends, thus protecting them nances, and the reconstruction of associ- from sunlight and drying actions. WHEN construction projects involve ated driveways and sidewalks. The final element of the tree preserva- the rehabilitation of streets and Conventional methods of tree preser- tion measures involved explicit contract utilities within established neighborhoods, vation generally involve the erection of language pertaining to the performance there is considerable potential for inciden- snow fencing and other hard physical bar- of the work and the assessment of tal damage to adjacent driveways, side- riers to protect trees during construction. penalties in the event of injury to a tree. walks, and parkway trees. This is due In this contract we were able to accom- This language gave specific instructions primarily to the confined work area plish the goal of tree protection by regarding the location and execution of available to the contractor and the large measures involving worker education, the root cutting and excavation. Further - number of trees. Damage to sidewalks, posting tree preservation signs, and root more, it imposed progressive monetary driveways, and turf can be corrected by pruning, all addressed by contract Ian- penalties for each violation of the protec- additional reconstruction work but the guage stipulating the assessment of penal- tion provisions and allowed the assess - damage that occurs to mature trees is ties for injury to trees. The cost of tree ment of liquidated damages for injury to often irreversible. The city of Naperville protection was substantially reduced by a tree, based upon the guideline entitled has taken steps to mitigate damage to eliminating physical barriers. Valuation of Landscape Trees and Shrubs trees during construction. In addition to the cost, physical bar- and Other Plants, 1988 edition. Root The city's 1992 Mill and Overlay and riers such as snow fencing can impose ad- pruning was included as a pay item in the Curb Replacement project rehabilitated ditional hardships on the neighborhood contract based upon a unit price per lineal t sections of eight streets with a combined in terms of visual obstruction and dif- ft for te"Earth a c at Tree ee R over length of 2.35 miles. These streets were ficulty in maintaining existing parkway all of the trees. part of an established residential district areas during reconstruction. preservation Based upon the suc implemen with homes dating back as far as the Worker Education tation of this project and virtually no 1860s, many of significant historical im- portance to the community. The streets Educating the project's workers on the damage to any of the existing trees, we in this area were reconstructed with con- need for tree protection was one of the feel that this tree preservation program crete back in the early 1920s. Since then, focal points of our tree preservation pro- was a complete success. Positive com- they were overlaid with asphalt and are gram. Explicit details pertaining to the ments on the program and the execution typically 25 ft wide with grass parkways limits of construction were included in the of the work were received from the city's measuring approximately 14 ft from the contract documents. Furthermore, in- forestry section and others in the com- curb to the sidewalk. In this parkway structions were given to the contractor at munity knowledgeable in the maintenance there are numerous mature trees, pre- the preconstruction meeting regarding the and care of mature urban forests. The dominantly Norway maples, oaks, ashes, execution of the work and the preserva- contractor also related very positive com- and elms. tion of trees. Informational handouts ex- ments concerning the structure of the During the initial planning stages for plaining the importance of tree preserva- and r imp ment d the city on oc efforts this project, it was recognized that the tion were given to each worker entering preservation of existing trees was going the work site. By educating the workers to stimulate worker education, which is to be a critical element of the work. Con- on the importance of preserving the trees, the key to effective tree preservation. terns raised by local residents about the we were able to mitigate the potential o We and would eencourage se measures t - potential for tree damage confirmed and damage before it even had an opportuni- preserve ties es nd ag e n ies tog xeroontruio measures re s to reinforced the city's commitment to ad- ty to occur. dress this matter in the contract plans and To constantly remind the workers of by maintaining the majestic beauty of tree the execution of the work. the importance of tree preservation, large, lined streets for decades to come. ❑ O ❑ PUBLIC WORKS for September, 1993 86