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HomeMy WebLinkAbout1999-08-31 OPH Ltr to VV Garden Homes AssnCITY JI OAK PARK HEIGHTS 14168 North 57th Street • P.O. Box 2007 0 Oak Park Hei MN 55082-2007 9 Phone: 651/439-4439 • Fax: 651/439-0574 Au 31, 1999 Valle View Garden Homes Association 14913 57`h Street Oak Park Hei MN 55082 Re: Stormwater Improvements In m Ma 13, 1999 letter I su a series of stormwater improvements for the rear y ards of the homes alon 57 Street and stated that I wanted to complete an elevation surve of the area and observe a si rainstorm. M tar for makin the improvements was b Labor Da The elevation surve was competed in June and refined this last week b surve the proposed route for the diversion ditch. On Wednesda Au 18, 1999 1 was finall able to observe a si storm. The storm was a t summer downpour that lasted about 30 minutes. M observations durin the storm and research performed this summer lead me to the followin conclusions/observations: 1 The amount of stormwater comin from the nei to the south is minor as compared to the rain from the roofs in y our nei Creatin a ditch to catch the water from the south, as su in the Ma 13, 1999 letter, would not be effective. 2. The drain located behind 14855 57" Street is capturin the majorit of the stormwater comin from the homes to the west of 14855. The stormwater comin off of the roof of 14855 is onl partiall captured b this drain. J. The water comin off of the roofs of 14855 and the homes to the east is the majorit of the water flowin throu the rest of the y ards to the east. 4. The desi of the g ara g e roofs directs a si portion of the stormwater from the front roofs and g ara g e roofs to the back y ards. This is especiall true for 14865 and 14873 where almost all of the water from the g ara g e roof is directed to the back y ard. 5. The elevation of the stormsewer inlet behind 14875 is hi than the back and is not interceptin an stormwater. 6. The stormsewer inlet behind 14975 cannot lowered without a lar expenditure. 7. There is a utilit easement extendin from the back propert line 25 feet into y our properties where the Cit can make improvements. This area is almost entirel within the woods. Tree Cit U.S.A. Valley view Storrnwater August 31, 1999 8. A diversion ditch starting at the center of the low area behind 14565 is feasible. For the diversion ditch to be effective will have to begin outside of the utility easement. The diversion ditch would catch the water from the roofs of 14855, 14863, and 14565, as well as, most of the water from the neighborhood to the south. The diversion could have a maximum slope of 3.5 %. 9. Some trees will be lost during construction of the diversion ditch. one tree near the edge of the proposed ditch is already leaning and may be starting to fall. 1 0. Lining of the ditch would be with rocks. Grass will not grow in the woods. 11. There are downed branches/trees/limbs that need to be cleared from the area by the homeowners or association. 12. The City of oak Park Heights does not have a stormwater utility fund or any other source of funding for this project other than assessing the work back to the benefiting homeowners. 13. once completed the City does not have stormwater utility fund to maintain the ditch. Diversion Ditch: The proposed diversion ditch is shown on the enclosed drawing. It starts behind 14865 and leads to the stormwater drain behind 14575. It will capture the water from 14855, 14563 and part of the water from 14865 and the neighborhood to the south. I have installed stakes at the centerline of the proposed ditch; grade stakes in holes showing the depth of the diversion and fill stakes at the downhill edge of the ditch where the dirt from the ditch will be deposited. The Y proposed ditch will start approximate) 3 feet south of the centerline matching the existing grade. It will be tapered to the depth designated at the centerline and then taper to match grade at approximately 3 feet north of the centerline. Starting three feet north of the centerline the dirt from the ditch will be deposited to form short berm at an elevation at least 6 inches higher than the centerline elevation. This ditch would best be dug by hand. Hand digging will create the least harm to the vegetation in the area. Now that firm plans are prepared I have contacted the Washington County Sentence to Serve Program and scheduled the digging of the diversion ditch for October 21 and 22. If the property owners or association could clear out the dead branches and clear the area too four feet either side of the centerline of the ditch it would be helpful. The area to the north of the proposed ditch where the dirt from the ditch will be deposited to form the downhill bank needs the most clearing. The second best option is to rent a very small backhoe. The last choice is to use the skid- loader we will be renting in September or October for some work in our hockey rinks and a few other sites. As noted above there are no funds set aside for stormwater improvements in the 1999 budget. Re- direct Garage roof water to the front: The diversion ditch will help 14873 eliminate the water flowing into his yard from behind his partially completed wall. It will not stop the large amount of roof water coming off of his and 14865's garage roofs and Bowing between their homes. This water needs to be re- directed to the front of their homes by the use of roof gutters. The fronts of the homes already have gutters. Gutters on all of the homes will help to reduce the amount of roof water flowing through the back yards. The roof gutters are a homeowner's choice and cannot be funded by City funds. Valley 'View 5tormwater August 31, 1999 Other items: The repairs to stormwater drain behind 14913 are still recommended to reduce the erosion of the yards. The extension of the horseshoe berm that was added last year is not going to be necessary. The diversion ditch should capture the water that would have been captured by the extension. Stormwater° Utility: The City Council will be holding public hearings- for the creation of . g a stormwater utility fund. The fund would be used to finance stormwater improvements and maintenance activities. The . proposal is to finance the fund with a $1.00 er Nousehold fee on the monthly utility bills. Commercial developments woul d be charged ` p based on acreage and at a higher rate since they have larger amounts of impervious . p surfaces. If this utility were formed then funds would be available for maintenance and to study other improvements. If you have any questions please contact me when I return from military duty on September 27, 1999. Sincerely; Jay E. Johnson, PE Public Works Director CC: Mayor and City Council City Administrator Washington Co. Sentence to Serve