Columbus Wash: Phase II

Project Description

The extension of underground storm drainage improvements are underway between Pima Street and Grant Road on Ralph Avenue, Seneca Street, and Belvedere Avenue. These improvements will provide the underground infrastructure for the Columbus Wash Drainage Improvements Phase II. When complete, the flooding to neighborhood and streets will be better conveyed and floodplain limits will be reduced. The reduction of floodplain limits and changes to the FEMA floodplain classification will eliminate the need for flood insurance for many property owners.

The Contractor is Granite Construction Company and the cost of the improvements is $9, 939,962.00. The project began in June 2007 and will take at least 11 months to complete (end of May 2008), weather permitting.

What To Expect

Phased Construction

The implementation of the construction is very complicated. The work described below will begin at Ralph Avenue near Grant Road and progress upstream (south) along Ralph Avenue, easterly along Seneca Street, south along Belvedere Avenue, and terminate south of Pima Street. Some work will be done at the intersections of Catalina Avenue at Seneca Street and Catalina Avenue at Pima Street. Expect the phasing of the work to be similar to the following:

1. Relocate and construct new sanitary sewer lines: The existing sanitary sewer lines must be replaced with new materials and relocated to each side of the street to make room for the new underground box culverts that will be installed down the center of the street. The existing individual house services will be reconnected to the new sewer main. The utility trenches will be backfilled with recycled asphalt materials and maintained until the road can be repaved.

2. Relocate the existing water mains: The existing water mains will also need to be replaced with new materials along both sides of the street. Existing water services will be reconnected to the new water mains along the frontage of each property.

3. Install the underground storm drain: Two rows of 8’x9’ box culverts will be installed down the center of the road from Grant Road to Pima Street along Ralph Avenue, Seneca Street, and Belvedere Avenue. The boxes will require a 17-ft deep excavation in some areas. Driver access will be interrupted for no more than two days along the frontages of two homes at a time. The excavation will be backfilled the next day. Pedestrian access will be provided at all times. Residents will be asked to park next door along their neighbor’s frontage while work is done along your frontage.

4. Replace concrete curbs, driveways, and final paving: The concrete curbs and driveways will have to be removed and replaced to make the underground utility modifications. The final paving will be done a block at a time after the storm drain is complete for that block. Expect the downstream streets to be paved first while the utility modifications are being done ahead of them.

Frequently Asked Questions

Q. Why has it taken so long to get this project moving?
A. The project was designed to use cast in place reinforced box culverts in a ditch that is almost 18 feet deep in some places. The time needed to construct these structures is too long to have an excavation in front of your homes and be safe. We elected to use precast box culverts instead. This will reduce the time an excavation is open significantly (three days versus 30 days) and make the construction bearable and safer for the affected residents. The cost to build this way is more expensive. We do not have enough money in our budget to build the entire project at this time.

Q. How much of the storm drain system can you build now?
A. We have estimated that we can build the storm drain infrastructure in Ralph Avenue, Seneca Street, and Belvedere Boulevard from Grant Road to Pima Street with the $10M available to us today. This cost includes relocating both sewer and water. We will also replace the existing curbs, rebuild driveways, and repave each affected street. 

Q. How does this help us if you can only build part of the project?
A. The City of Tucson has remapped the entire area based upon existing conditions and expected storm flows. This administrative work, done as part of this engineering design, will remove many residents from the flood plain before even beginning construction. This will be done by reclassifying the flood zone for many of the other residents previously shown to be in an AE Zone to a Zone X.

      The cost of construction materials has risen significantly during the past few years. Any infrastructure we can construct now will mean fewer infrastructures to build in the future. We will be saving money in the future because the costs of construction will be much higher than today and we have less to build to complete the balance of this design.  

Q.What is an AE Zone?
A.  An AE Zone is a FEMA flood zone designation. Properties within this zone can potentially be flooded during the 100-yr-storm event. Property owners are required by their lenders to purchase flood insurance.

Q.What does a Zone X mean?
A.  An X Zone means there is less chance of flooding during a 100-yr-storm event. FEMA does not require flood insurance for an X Zone and leaves it up to the lender as to whether flood insurance is required. Lenders who do require flood insurance will generally reduce the amount of the flood insurance premium.

Q. When is the soonest construction can begin?
A. The City of Tucson already has a contractor on board who will be available to begin next month (April 2007).

Q. When construction begins, what will be done first?
A. This project involves the construction of a 16’wide x 9’high reinforced box culvert down the center of Ralph Street, Seneca Street, and Belvedere Avenue. In order to install this size structure, we will have to relocate existing utilities such as sanitary sewer and water.  The first thing to be done is to mill the existing pavement in place and remove the curbs. This will allow room to get to your homes and to relocate utilities from their present locations to locations that are out of the way of the new storm drain box culvert. The milled surface will reduce the dust caused by construction.

Q. What utilities need to be relocated and how long will we be out of service?
A. This project involves the construction of a 16’wide x 9’ high reinforced box culvert down the middle of the street. We will have to relocate the sanitary sewer and water mains from the street to make room for the storm drain.

 The sanitary sewer will be relocated from the center of the street to each side of the street. The new sewer lines will be constructed in its entirety before service will be interrupted for part of a day. Residents will be notified in advance when the reconnection will be made. Your notification will have instructions asking residents to not flush their toilets or run water down their drains while your sewer is being reconnected to the new line.

We will also have to replace existing water mains on both sides of the street. The line will be constructed in its entirety before we attempt to make a reconnection. This disconnection/reconnection will take a few hours. Residents will be notified in advance that they will be out of water for no more than 4 hours.

Q. Will our access be affected and how safe will the excavation be for adjacent
residents?

  1. Once the utilities have been relocated, the center of the street will be excavated for the new reinforced box culverts. The excavation will be 18-ft deep in some areas. The trench will be barricaded and fenced to make it safe to residents during non- work hours. Pedestrians will have room to walk by the excavation. You will be able to drive into your driveways as long as work is not in front of your home. 

An excavation (hole) will be made approximately 100-ft long by 20-ft wide at a time. Approximately 65-ft of culvert will be installed daily and the portion installed will be covered up. (You may have to share your neighbor’s frontage to park your cars over night when the work is in front of your home). You will be able to use your driveway the next day. As the storm drain is completed, the curbs will be replaced and the street repaved on each block.

Q. How long will construction take?
A. We expect construction to take no longer than 11 months and be done in an orderly fashion. Work will begin on Ralph Street and progress southerly to Seneca Street. It will turn east to Belvedere Avenue. We should be to Belvedere Avenue by September 2007 with the storm drain. Utility relocation work will continue from the first day until it is complete.  Storm drain work on Belvedere Avenue will begin as soon as the monsoon season is over. The project should be complete by March 2008 (weather permitting).

Documents

Who To Call

We apologize in advance for any inconvenience to businesses, residents and the traveling public.  To contact us if there is a problem or if you have a special need as it relates to utility service, access to your property, or the traffic circulation in your neighborhood during construction, please call us at the following numbers:

Contractor: Granite Construction Company

Superintendent: Robert Frost (520) 403-4089
Project Engineer: Jeramy Bohne (520) 325-9698

The City of Tucson

Field Representative: David Stiffey (520) 791-5100
Project Manager:  Fred Felix (520) 837-6620

Thank you for your patience as we work to provide a better community.