Agenda - Public Works Committee - 07/19/2005

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CASE UPDATE ON 5518-5520 144th COURT DRAINAGE ISSUES By: Leonard Linton, Civil Engineer II Background: StaW was contacted by Rebecca Moser, 5520 144th Court, in the summer of 2004 regarding drainage problems in the back yard. Maps of the area and the site are attached and are referenced in the case. Staff made several site visits-and became aware of the problems at 5518 144th Court during one of the visits. These lots are in the Ponds Subdivision. The tree preservation ordinance was enacted as this project was nearing final approval. The selection of trees to be preserved was made in the field as the grading preparations were made. The elevations around the trees were not checked by the project engineer to verify impacts to the grading plans. These houses were subsequently constructed per the ap tPhroved grading plan. The same builder constructed both houses. The trees on 5520 1'44t Court were above the proposed grades and were protected by boulder retaining walls constructed by the developer. The trees on 5518 144th Court were below the proposed grades and were not enclosed by any structures. The resident of Lot 8 contacted the City regarding installing a fence along the common lot line. A small block retaining wall was constructed along the property line so that the fence could be installed. Visual observation indicates that fences were constructed on Lots 6 and 7 and fill may have been placed inthe drainage and utility easement to t:acilitate construction of the fences. A Certificate of Grading was submitted for Lot 23 after the house was constructed. The certificate was filed with the building permit. Staff reviewed the Certificate of Grading after the Moser's contacted the City. The certificate of grading did not match the approved grading plan. Staff wrote two letters to the builder' requesting a plan for remediation of the problem. The developer and their engineer were copied on both letters. Meetings were held at City hall .with the builder, the Moser's and the Pugh's. The builder was given a deadline in the second letter, after which the City would undertake the work and charge the work against the developer's escrow fees held by the City. The Pugh's wanted to retain the trees on their lot, and felt that if the drainage from the west was cut off the water would soak into the ground quickly and not cause a problem. The elevation at the base of the trees was the same elevation as the storm sewer outlet between Lots 4 and 5 so installation of a pipe was not possible. The initial plan of action was to create a swale across Lot 23 to channel most of the water to the west. This was subsequently modified to installing drain tile across Lot 23 as the swale would have been outside the drainage and utility easement and was viewed as a trip hazard by the residents. The plan was amended to remove two trees on Lot 24 .just before construction, one of the trees was an oak, one was not. The oak was exhibiting signs of oak wilt 'and would need to be removed in the future. The trees were so close that removing one would damage the other so both were removed.