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Comprehensive Drainage Plan

Being situated between the Texas Hill Country to the north and the lower lying areas of San Antonio proper, Shavano Park has always experienced significant drainage challenges. These challenges intensified during from the 1990's with the rapid development within and around Shavano Park. In 1997 the City commissioned the Vickery Study to analyze the drainage pathways within the City. This engineer study guided City efforts to provide necessary drainage infrastructure for the City in the early 2000's, but with the rapid development in the City the study became outdated quickly.

In 2010 the Town Plan made drainage infrastructure a priority for the City and made note of two drainage improvements made during the 2000's. The Quarry Retention Pond northeast of Loop 1604 & NW Military Highway (see picture at right) provides extensive water storage capacity and helps alleviate water flow along Olmos Creek.

InterceptorChannelDenton Communities also constructed an interceptor channel around the Huntington development and Eastbound 1604 commercial properties to alleviate periodic flooding along Wagon Trail.

The Planning & Zoning Commission in 2014 formed a Drainage sub-committee to review and prioritize drainage infrastructure projects across the City. The sub-committee, led by Richard Lazor, presented their analysis to City Council at the January 25, 2016 meeting.

The Drainage sub-committee organized drainage problems into eight key areas and labeled them on the 1999 Vickery Study. In addition to the drainage prioritization, staff has listed rough estimates for the scale of efforts required to address drainage issues in each zone. The estimated scale of effort is coded into a Staff Internal, Moderate Expenditure or Capital Project.

  • A Staff Internal is a project the Public Works / Water Director estimates could be done in house with the City’s limited manpower and equipment. Example: 1-5 days spent clearing a drainage channel of brush.
  • A Moderate Expenditure project is estimated to require contracting an outside firm and an expenditure under $50,000. Example: Expanding a drainage channel to accommodate more water flow.
  • A Capital Project is estimated to be a $50,000+ project and require extensive re-grading, culvert installation or other major construction. Example: Installing a culvert or building a retention pond.

The P&Z drainage priority is listed below with staff comments reflected in the sub-bullets:Drainage Priority Map

  • 1A – Municipal Tract / Elm Spring & Bikeway Lane
    • This is a Capital Project requirement with several potential solutions that will take deliberate planning and analysis.
    • If the MPO approves the NW Military Highway expansion to be completed in a timely manner, a joint bid would likely be the best move for the City to help reduce cost for installing major box culverts under Elm Springs to help with all of the properties west of Military Hwy.
    • The culverts coming down Elm Springs would likely need to go straight across though 2 private properties to get to Olmos Creek without causing any further impact to the muni-track or residents along Bikeway.
  • 1B – Southeast “Old Shavano” – Windmill, Bent Oak, and Cliffside
    • Windmill could be addressed by raising the road and adding 2 shallow box culverts, this would be a moderate expenditure.  Bent Oak may also be considered for a culvert under the road.
    • The natural drainage ditches that run from the north to south and cross Bent Oak and Cliffside both need the channel cleaned out.  This project will take approximately 2 weeks with City crews. Time could be cut shorter if we could get a D6 dozer to help clear the area.
    • Some other areas may be a challenge to completely mitigate

  • 3 – Shavano Estates in vicinity of Painted Post and Ripple Creek
    • If the water from area 1A is picked up and addressed along Elm Springs, then this would reduce the flow of water under De Zavala through Ottawa Run which comes out on Ripple Creek. Ottawa Run just needs some general clean up and mowing, which the City crews could address
    • Another solution involves moving the storm water runoff parallel to DeZavala from the municipal tract in a westerly direction to Olmos Creek
    • A mitigation option is to create a natural water retention area  vicinity the SW corner of the municipal tract.
  • 4 – Northwest “Old Shavano”
    • Honey Bee could be addressed by raising the road and adding 2 shallow box culverts, this would be a moderate expenditure.
    • Turkey Creek has been cleaned up to the best that it can without regrading around houses.
  • 5 – Northeast “Old Shavano”
    • Chimney Rock would be a moderate to capital expenditure. The roadway needs raised with culverts under the road. Driveways for 3 residents would need to be reconstructed as well to match the road. Also the channel would need to be cleaned out along both sides of the roadway.
    • Saddletree was recently cleaned out, it just needs to be maintained.
  • 6 – Central “Old Shavano” - Fawn Drive – Saddletree Road
    • Around the Fawn Drive and Saddletree area the bar ditches need to be reshaped and cleaned out. This would be a moderate expenditure, due to the engineering and grading involved to make sure the water would not be shifted into a house and create additional issues.
  • 7 – Wagon Trail / Collins Circle
    • The drainage channel that was installed by the developer needs to be completed. Grading should be checked from behind 113 Wagon trail and go all the way to NW Military. By doing so the water would flow into the channel that goes into the Olmos Creek. This is on the edge of a moderate to capital expenditure.
    • Collins Circle needs to be graded into a culvert on the north side and then empty on the south side into the channel crossing NW Military into the Olmos Creek bed. 
  • 8 -  Lower Cliffside
    • This area needs all the bar ditches reshaped and graded into the Salado Creek. This could be on the edge of a moderate to capital expenditure depending on the scope of work and how far up each side street the City decides to address.
To help fund future capital projects to address drainage, the City Council approved Ordinance No. O-2016-002 at the February 22, 2016 meeting. This budget amendment ordinance moved $1,020,445 from unreserved fund balance to the drainage category of the capital fund. This allocation brought total City capital reserves to address the drainage projects in the Planning & Zoning Commission plan to $1,462,971. This money is available for future budget years so that the City can address needed drainage projects without upsetting our annual balanced budget.