12. Authorize execution of a construction maintenance contract with AUSTIN FILTER SYSTEMS, INC. for the J. J. Seabrook Stream Restoration, Rain Garden, and Urban Trail Project in the amount of $1,729,775.45 plus a $172,977.55 contingency, for a total contract amount not to exceed $1,902,753. Related to Items #28, #66 and #67. ( Notes: This contract will be awarded in compliance with City Code Chapter 2-9A (Minority Owned and Women Owned Business Enterprise Procurement Program) by meeting the goals with 15.25% MBE and 4.74% WBE subcontractor participation. ) 28. Approve a resolution authorizing the negotiation and execution of all documents and instruments necessary or desirable to purchase or otherwise acquire an estimated 140 properties at high risk of flooding located outside of the United States Army Corps of Engineers (USACE) buyout project area that will remain at risk of flooding in the 25-year floodplain within the Onion Creek Forest, Onion Creek Plantations, Yarrabee Bend, and Silverstone neighborhoods (Lower Onion Creek area) in the Onion Creek watershed, in an amount not to exceed $31,000,000. Related to Items #12, #66 and #67. 66. Approve a resolution declaring the City of Austin's official intent to reimburse itself from Certificates of Obligation to be issued for expenditures in the total amount of $35,500,000 for costs associated with the Onion Creek buyouts of single family houses in flood-prone areas and related improvements. Related to Items #12, #28 and #67. 67. Approve an ordinance amending the Fiscal Year 2013-2014 Watershed Protection Department Capital Budget (Ordinance No. 20130909-002) to increase appropriations by $35,500,000 for the buyout and demolition of single family houses in the floodplain of Onion Creek near the intersection of South Pleasant Valley Road and East William Cannon Drive. Related to Items #12, #28 and #66.