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HomeMy WebLinkAboutMiscellaneous <<~ COLLEGE STATION P. O. Box 9960 . 1101 Texas Avenue Tel: 409 764 3500 College Station, TX 77842 MEMORANDUM TO: Planning & Zoning Commission G FROM: VeronicaJ.B. Morgan, Asst. City Engineer ~ DATE: September 25, 1997 RE: DRAINAGE ORDINANCE AMENDMENT Attached you will find a proposed drainage ordinance amendment which is written'to accomplish two things. . Add language within the drainage ordinance which requires development to comply . with the newly adopted City of College Station Comprehensive Plan and its elements. The current drainage ordinance was originally written as a flood hazard ,ordinance. These changes have been made in an effort to ensure that development proposals in and around , floodplain areas not only ensure flood hazard safety but also achieve the intent of the elements of the Plan. and . Changes the appeal body from the Zoning Board of Adjustment to the Planning & Zoning Commission. Since the drainage ordinance will be more closely tied with the Comprehensive Plan, we felt the appeals and variances should be appealed to the body who was most knowledgeable ofthe Plan and its elements. . Home of Texas A&M University <<~ COLLEGE STATION P. O. Box 9960 1101 Texas Avenue Tel: 409 764 3500 College Station, TX 77842 MEMORANDUM TO: Honorable Mayor and City Councilmen Planning & Zoning Commissioners FROM: Veronica Morgan, P.E., Assistant City Engineer Jane R. Kee, AICP, City Planner RE: Carter Creek Relocation Proposal and Drainage Ordinance Amendment In 1986 the City Council passed a resolution expressing community support for a floodplain reclamation project relocating and channelizing Carter's Creek. This resolution came about as a result of a project Mike Davis was working on at the time. In June of this year, Mr. Davis presented to the City of College StatioJYa "Carter's Creek Relocation Report" and requested that this be forwarded to FEMA (Federal Emergency Management Agency) for a conditional letter of map revisions (CLOMR). This project also involves the City of Bryan. The report is presented on behalf of the Jim Sowell Construction Co., Inc., property owner. As you are well aware, the Comprehensive Plan was adopted in August of this year by resolution. The staff is and has been working to implement the various goal and objective statements and policy statements through ordinance amendments. One such amendment involves the Drainage Ordinance. This ordinance is designed to regulate development to avoid flooding. What it does not currently do is specifically address certain drainage areas referenced in the Comprehensive Plan as needing protection. The amendment before the P&Z on 10-2 adds langUage to the Drainage Ordinance that does two things: 1. Provides for creation of a Drainage Variance Board to hear requests from any aspect of the ordinance. Presently variances are heard by the Zoning Board of Adjustment. The Drainage Board is proposed to have 3 members required to have engineering background, one member required to have a real-estate background and one member required to have an environmentaVconservation background. 2. Provides for a thirty day review time, rather than a 10 day review time, for proposals involving the following specific drainage areas referenced in the Comprehensive Plan: The entirety of Carter's Creek, The main channel and south fork of Lick Creek, Wolf Pen Creek from SH 6 By-Pass to the confluence with Carter's Creek and Home of Texas A&M University The Brazos River. One of the objectives of the Comprehensive Plan states "College Station should prohibit reclamation of the floodway associated with Carter's Creek, Lick Creek, Wolf Pen Creek and the Brazos River in order to prevent upstream flooding, avoid long term structural and erosion problems associated with floodplain reclamation, and to provide a city wide network of natural open space." In order to actually prohibit proposals that aim to reclaim in these areas, the City will have to be prepared to make property acquisitions. The thirty day time frall1e will give staff the time to notify the City Council that a proposal is pending and receive direction whether to proceed with property acquisition or to proceed with the permit process. This amendment will not impact Mike Davis' project unless Council determines that acquisition is the more desirable direction rather than permitting. This is a topic appropriatefor a Council executive session ifstaffis so directed. A long term goal to implement this specific objective .statement and others that refer to preserVation of natural open space and provision of greenbelts linking various areas of town, is to prepare a more detailed plan of the floodplain areas defining and prioritizing those areas targeted for preservation as shoWn. on the Parks and Open Space Plan. The Parks Board is currently working with a TAMU class and the Brazos Greenways Council in doing just this. A program for acquisition will be a logical outcome of this process as well. It may be too early to specify a time frame for this, but staff would anticipate at least one year for development given the current workload of Parks, Development Services and Engineering. In the interim, the 30 day review period will give Council the opportunity to consider acquisition as proposals are made. attachments: Resolution from 1986 Figures "before and after" of the Carter Creek project Letters from Bryan and College Station to Mike Davis Drainage ordinance am.endm.ent "-6 ( ~. W~tr ~etL--\h~\oc. \)\? COLLEGE STATION yqO P. O. Box 9960 . 1101 Texas Avenue Tel: 409 764 3500 College Station, TX 77842 September 8, 1997 Riverview Inc. Attn: Mike Davis 4002 Aspen Bryan, Texas 77802 RE: Carter Creek Relocation Project Dear Mr. Davis: We have completed the review of your "Carter Creek Relocation" concept dated June 1997. In concert with the City of Bryan development engineering staf( we discussed the concept and details of your design. There are maintenance and design issues that need to be addressed prior to approval of the relocation concept. The following is a list of concerns currently identified by the joint Bryan and College Station review: 1. As previously discussed there are concerns with the maintenance of the proposed facility. a If the City can not maintain the proposed improvements, a plan to ensure the design "n" values and other assumptions will be required. b. The City has some concern with regard to the "flapper" gates being installed. as part of the detention basins at the lower end of the project. This design has the potential of not functioning properly due to debris getting caught within the opening and not allowing them to close. You have stated that the gates provide for added protection, but that if in the event they did not operate properly there would be no impact to the downstream. properties. If this is in fact the case, it would be better to remove the,gates and portions of the benned areas in order to utilize the additional capacity for the entire channel . 2. In an effort to determine the amount of sediment load the channel will be carrying as a result. of this project, you will need to submit a siltloading analysis. This information will help to determine the maintenance schedule necessary to maintain the design assumptions associated with this project. Home of Texas A&M University Mr. Mike Davis Carter Creek Relocation Project September 8, 1997 Page 2 3. As part of the maintenance concerns for this project, the City will require the channel bottom to be concrete lined. This lining will provide a solid working surface to perform maintenance activities. 4. The developer will be responsible for submitting a financial guarantee that is equal to a sealed engineer's estimate for all costs associated with the construction of this project. Please submit this information at your earliest convenience. The approval of this conceptual plan is contingent upon receiving this information and full compliance with the City of College Station Drainage Policy and Design Standards manual. If you have any questions, feel free to contact either of us at 764-3570. xc: Sabine McCully, Senior Planner, City of College Station Shirley Volk, Development Coordinator, City of College Station Paul Kaspar, Graduate Engineer, City of College Station Mark Smith, Dir. of Public Works, City of College Station KentLaza,City Engineer, City of College Station Steve Homeyer, Asst. to the City Engineer, City of College Station Linda Huff, Development Engineering Division Manager, City of Bryan Lisa Hagerman, Development Engineer, City of Bryan Greg Taggart, Municipal Development GroUp ~erCreek Relocation Project D.P. File RECEIVED SEP 0 91997 September 2, 1997 P. O. BOX 1000 . BRYAN, TEXAS 77B05 . (409) 361 -3600 RE: Carter Creek Relocation Project ( ~~ '~ ~if~ 'P~ ~y Mr. Mike Davis Riverview, Inc. 4002 Aspen Bryan, Texas 77801 Dear Mr. Davis: We have completed the review of the FEMA submittal prepared for the Carter Creek Relocation Project and have several concerns. . The long-term maintenance of the channel will need to be provided by the City, and therefore concrete lining along with access for maintenance equipment will be required. The developers will need to provide short- term maintenance by way of a bond or cash equivalent to the cost of the initial 10 to 15 years. . Additional easement for bikelhike type paths will need to be provided along both sides of the channel. . An analysis will need to be performed to better predict the amount of siltation, which can be expected. . We have concerns with the proposed alignment at the upstream end in relation to the existing creek. The proposed. alignment begins just beyond an area in the creek where a 900 bend occurs. We believe that the creek will eventually bypass the channel at this 900 bend. In addition, the weir and drop structure on the north end of the project are of concern, especially with respect to siltation occurring upstream and outside the property owned by this group. . Finally, we require that the City of College Station approve this proposal and that the City Limit relocations be performed prior to any submittals. We are in receipt of City of College Station's letter dated August 27, 1997 where their concerns were addressed. If you have any questions, please call me at 361-3842. ~~ JL1Ls 4H- Linda Grubbs Huff, P.E. Development Engineering Division Manager ' Cc: Lisa Hagerman, Development Engineer Tom Coyle, Director of Development Services Rick Conner, Director of Public Works Kent Laza, City Engineer, City'ofCollege Station Jane Kee, City Planner, City of College Station File