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Home My WebLink About2.d. Tree Removal/Preservation, 2009 Street Improvements Project, City Project #426AGENDA ITEM: Tree Removal /Preservation, 2009 Street Improvements Project, City Project #426 AGENDA SECTION: pi5GI,(551 Ohl. PREPARED BY: Andrew J. Brotzler, PE, City Engineer lri AGENDA NO. 9 7, ATTACHMENTS: Location Map; Option Figures; Map; Photos APPROVED BY: Oh.) RECOMMENDED ACTION: Council discussion and direction. ROSEMOUNT BACKGROUND: CITY COUNCIL City Council Special Work Session: March 11, 2009 EXECUTIVE SUMMARY On January 20, 2009, City Council authorized preparation of plans and specifications for the 2009 Street Improvement Project, designated as City Project #426. This project includes the reconstruction of streets, watermain, sanitary sewer, and storm sewer on Damask Avenue West, Upper 150 Street West, Dallara Avenue West, and Damask Court. The proposed reconstruction of existing watermain and sanitary sewer includes the replacement of water and sanitary sewer services to the right -of -way line. The attached location map illustrates the project area. Through the completion of a topographic survey of the project area and detail design for the project, a significant number of mature trees in the project area were determined to be located within the street right -of -way and project excavation limits and, as such, would typically be removed prior to the start of construction. To give full consideration to the issue of tree preservation on the project, options, each with various advantages and disadvantages have been developed. Staff is requesting Council discussion and direction following review of the information detailed below. 1. Issues The neighborhoods in the project area date back to the early 1970's, and at a point following installation of public utilities, several trees were planted in front yards and adjacent to the streets within the streets right of -way. These trees were planted with no clear pattern or layout for location (see attached photographs for illustration). Age of the trees appear to range from 10 to 40 years, with many at the upper end of that range, consistent with the age of the development. Species type is widely varied throughout the project area, and includes green ash, American elm, silver maple, hackberry, and different types of conifers. These types of trees are common in residential neighborhoods, and other than their age and size are not considered unique in character or value. A small number of trees in the project area appear to exhibit signs of distress or disease. The trees identified for potential removal were all planted either within public right -of -way for the roads, or close to lateral water and /or sanitary sewer services which extend from the street into each property. In some instances the trees were planted on top of these services. Replacement of these utility services is typically conducted to the right -of- way /property line. Trees in the immediate vicinity of this excavation generally need to be removed prior to excavation, as excavation in close proximity can topple a tree or G: \ENGPROJ \426 \Tree Issue CWS 3- 11- 09.doc cause root damage that may cause the tree to die at some point in the future. An estimate of the trees to be removed follows, along with a description of each tree preservation option. In addition, an overall map of the project is attached illustrating trees within the project area by type of conflict and whether preservation measures can address the conflict. Number of Trees 33 64 97 Conflict Associated With Storm Sewer* Utility Services TOTAL Note: storm sewer installation requires the removal of trees that cannot be addressed using the preservation options presented below. Reconfiguration of the storm sewer layout was examined, but no viable alternatives were identified that could significantly reduce tree impacts. Physical constraints on reconfiguration include available space within right -of -way, depth of storm sewer needed to provide flow, and location of connection points to existing storm sewer. 2. Mitigation Options Four options for the full and /or partial replacement of water and sanitary sewer services have been developed. Each portion is described below with a summary of impacts and cost included in Table 1. See attached Figures A -D for a graphical depiction of each option identified. Preferred Option A: Typical Service Replacement. This option involves installation of sewer and water services to the property line to current City standards. It best ensures the current and future integrity and protection against future damage of the City -owned infrastructure within the right -of -way, however, requires the removal of the greatest number of trees throughout the project. In addition, each impacted homeowner would be given a choice of new replacement tree to be planted in a location outside the public right -of -way that would not be on private property in conflict with future utility excavation at such point that major maintenance or repair of services is necessary. Option B: Service Connection under Roadway. This option includes the extension of new sewer and water services from the main lines only to a point where a tree in conflict could be saved from removal. This installation would leave the existing service(s) under the tree, and a connection between old and new service would be located such that future service replacement would require the removal and replacement of a section of the adjacent roadway. This option saves the greatest number of trees from removal. Consequently, construction costs are estimated to be lower than Option A because of fewer tree removals and shorter service replacement length on the project. However, a higher future cost would be borne by the property owner for items required to complete the replacement of services, including: tree removal, greater length of service replacement, roadway removal, curb replacement, and pavement patching. In addition to higher property owner costs, potentially this option will also result in the long -term integrity of the street being compromised. Option C: Additional Service Installation for Future Connection. The third option is a modification of Option B with the addition of a new secondary sewer and water service for future connection. This option eliminates the need to replace a section of roadway by providing an alternate connection at the property line at such time the home service lines need to be replaced. However, similar to Option B, a connection in close proximity to the roadway would still exist and may cause damage to road infrastructure should a connection failure occur in the future. In addition, not every property is physically configured such that a second water and sewer service can be installed without impacting another tree (save one tree to remove another), or the driveway (future connection Alternative Estimated City Cost Trees Saved/ Removed Homeowner Risk ofDamage to Infrastructure Integrity of utilit r System and ROW Option A (preferred) Baseline None 97 Low Lowest Highest Option B -$1,200/lot $90,000 project total 62 35 Highest Highest Low Option C +$700 /lot +$52,500 project total 16 81 High High Hig Lowest Option D +$1,700 /lot +$127,500 project total 27 70 Lowest Low High under driveway). Therefore, this option does not benefit all properties and saves fewer trees than Option B. Option D: Service Installation Alternate Location and Current Connection. The fourth and final option addresses concerns with future roadway damage by removing the existing service to a point that does not impact the tree, while providing new service locations that avoid trees and completion of a full connection to existing lines within private property. No future connection would be required of the homeowner. Future damage to the roadway is minimized by replacing all service connections in the right -of -way. Based on physical layout, only certain properties are candidates for this option, and similar to Option C, a limited number of trees are saved. This option creates the largest impact to the properties yard, and requires the completion of work outside the right -of -way that is typically the responsibility of the property owner. This option also has the highest cost to the City due to the additional length of services installed with the project. Table 1 summarizes some of the general impacts of each option is included below. TABLE 1 Following an examination and comparison of all available options and impacts, the technically preferred alternative is Option A. All other alternatives compromise the integrity of the public infrastructure system and /or the public right -of -way to varying degrees. Should Council direct an alternative other than the preferred Option A, staff's proposed approach would be to discuss each tree with the property owner to identify trees that the property owner might prefer to have removed and replaced with a new tree (undesirable tree, damaged, location, etc.). This approach would attempt to minimize future risk and damage to the public utility system by allowing Option A installation in specific instances, where authorized by the property owner. SUMMARY: Staff is requesting Council provide direction to staff following discussion and consideration of the tree preservation alternatives presented above. 3 PRO: CON: NEW TREE OF HOMEOWNER TREE REMOVAL CHOICE (APPROX: 97 TREES) UTILITY SERVICE CONSTRUCTED PER CITY STANDARD REMOVE TREE NEW SANITARY SEWER SERVICE TO RIGHT OF WAY NEW WATER SERVICE TO RIGHT OF WAY HOUSE NEW TREE EXISTING RIGHT OF WAY 1� -1 1— CONCRETE CURB AND GUTTER LEGEND: EXISTING SANITARY SEWER PROPOSED SANITARY SEWER EXISTING WATERMAIN •I• PROPOSED WATERMAIN WIB Associates, Inc. 701 Xenia Avenue South, Suite 300 Minneapolis, MN 55416 www.wsbeng.can 76954148W- Fax 783541 -1700 MFRASTRUCTURE iENGINEERING 'PINNING (CONSTRUCTION 2009 STREET IMPROVEMENT PROJECT SERVICE OPTION A ,ROSEIMOUNT NT MINN ESOTA WSB Project No.01668-69 March 3, 2009 Figure Number A J PRO: SAVES TREE (APPROX: 62 TREES) MINIMAL TREE REMOVAL REQUIRED FOR SERVICES LESS CONSTRUCTION IMPACT TO YARD LOWER UPFRONT COST THAN OPTION "A" (APPROX:$1200 /LOT) NEW SANITARY SERVICE SERVICE CONNECTION AT BACK OF CURB LEGEND: EXISTING SANITARY SEWER PROPOSED SANITARY SEWER EXISTING WATERMAIN ■•PROPOSED WATERMAIN 701 Xenia Avenue South, Suite 300 Minneapolis, MN 55416 wvnv..com 7604Nm800 Fax 783141.1700 \IiFRASTRUCTURE ENGINEERING 'PLANNING *CONSTRUCTION j HOUSE SAVE TREE CON: SERVICES NOT INSTALLED TO CITY STANDARD RISK OF DAMAGE TO ROAD/TREE/UTILITY AT TIME OF FUTURE SERVICE REPLACEMENT COPPER TO COPPER WATER CONNECTION WITHIN RIGHT OF WAY CLAY TO PVC SEWER SERVICE CONNECTION DAMASK COURT POTENTIAL FUTURE ROAD RECONSTRUCTION AND MAINTENANCE COST DUE TO PROXIMITY TO ROAD TREE REMOVAL (APPROX: 35 TREES) 1�1�1 CONCRETE CURB AND GUTTER 4 4 NEW WATER SERVICE CONNECTION AT BACK OF CURB (COPPER TO COPPER CONNECTION) 2009 STREET IMPROVEMENT PROJECT SERVICE OPTION B "ROSEMOUNT MINNESOTA EXISTING RIGHT OF WAY WSB Project No.01668-69 March 3, 2009 Figure Number B PRO: SAVES TREE (APPROX: 16 TREES) SAVE TREE NEW SANITARY SERVI CONNECTION AT OF CURB NEW WATER SERVICE CONNECTION AT BACK OF CURB CON: ALL CONS LISTED IN OPTION "B" GREATER IMPACT TO YARD HIGHER COST THAN OPTION "A" (APPROX: $700 /LOT) TREE REMOVAL (APPROX: 81 TREES) DOES NOT BENEFIT ALL PROPERTIES COPPER TO COPPER CONNECTION WITHIN THE RIGHT OF WAY LESS TREES SAVED THAN OPTION "B" LARGER HOMEOWNER COST WITH FUTURE CONNECTION HOUSE LEGEND: (COPPER TO COPPER CONNECTION) EXISTING SANITARY SEWER PROPOSED SANITARY SEWER EXISTING WATERMAIN 1— PROPOSED WATERMAIN NEW SANITARY SEWER SERVICE FOR FUTURE CONNECT ION NEW WATER SERVICE W/ NEW CURB STOP FOR FUTURE CONNECTION EXISTING RIGHT OF WAY 1 CONCRETE CURB AND GUTTER AB Minneapolis, Xenia Avenue Suite 300 Minneapoleolis, MN 55416 www.wsbeng.com i► x Associates, Inc. 7&%414800 -Fax 783541-1700 .84GIEERP G s PLANNING s CONSTRUCTION 2009 STREET IMPROVEMENT PROJECT SERVICE OPTION C "ROSEMOUNT MINNESOTA WSB Project No.01668-69 March 3, 2009 Figure Number c PRO: SAVES TREE (APPROX: 27 TREES) NO FUTURE CONNECTION REQUIRED BY THE HOMEOWNER PROPERTY OWNER BENIFITS WITH SERVICE REPLACEMENT SAVE TREE REMOVE WATER SERVIC. TO BACK OF CURB AND GUTTER 1 CON: REMOVE SANITARY SERVICE TO BACK OF CURB AND GUTTER SAME CONS AS OPTION "B" AND OPTION "C" WITH THE EXCEPTION OF CONNECTION ISSUES AT RIGHT OF WAY TREE REMOVAL (APPROX: 70 TREES) HIGHER COST THAN OPTION "A" (APPROX: $1700 /LOT) LARGEST IMPACT TO YARD FUNDING ISSUES WITH WORK OUTSIDE OF PROJECT LIMITS DOES NOT BENEFIT ALL PROPERTIES HOUSE NEW SAIs ITARY SEWER SERVICE CONNECTION TO EXISTING SERVICE NEW WA ER SERVICE CONNEC ION TO EXISTING SERVICE EXISTING RIGHT OF WAY CONCRETE CURB CURB AND GUTTER LEGEND: EXISTING SANITARY SEWER —10— PROPOSED SANITARY SEWER EXISTING WATERMAIN PROPOSED WATERMAIN NOTE: THIS OPTION ASSUMES DRIVEWAY AS POTENTIAL LOCATION FOR NEW UTILITY SERVICES. WEB do Associates. Ine. 701 Xenia Avenue South, Suite 300 Minneapolis, MN 55416 www.wsbeng.com 763341-4800 -Fax 763341 -1700 \II FRASTRUCTURE 6 ENGINEERING 6 PLANNING U CONSTRUCTION 2009 STREET IMPROVEMENT PROJECT SERVICE OPTION D 'ROSEMOUNT MINNESOTA WSB Project No.01668-69 March 3, 2009 Figure Number D J 2009 Street Improvements Project V II I l l DAVENPORT C W H AVEN'•` PATH 143RD ST W U. 148 ST W 155TH ST W 156TH ST W DECEMBER 151ST ST W 153RD ST 151ST RT yl(_ 146TH ST W 148TH ST W .149TH ST CORNELL TRL W 156TH ST W UPPER 143RD 147Th ST W U. 147TH ST W 148TH ST W L 147TH a a z 0 0 480 980 1,920 2,880 TJGIS/City/MapslDepartrnental Maps/Engineering/Chris/2009 Raton Locate 3,840 Feet W z 0 z 143R 142ND ST W September 2008