04-12-14 Retreat/Special Meeting of La Porte City Council

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EXHIBIT G CONPREHENSIVE PLAN PRIORITY 15: DROUGHT TOLERANT PLANTINGS The City has already started a planned, systematic approach to sustainability through the judicious use of irrigation water, and plant materials that can withstand dry conditions when the plants are conditioned to do so. As a sidenote: a lot of people confuse xeriscape, using cacti and other desert plants as the “only way to go” to accomplish this. The reality is, that unless the soil is either elevated or very sandy, or both, those types of xeriscape plants do not do well in our wet, humid climate. The systematic approach to conditioning plants to enhance their drought tolerance is to utilize irrigation systems to “wean” the plants off water. This is accomplished by watering for longer periods and longer intervals. This forces the root systems to penetrate deeper into the soil to get the water needed, much like building muscles in the gym. If the plant roots don’t have to go far to get water because they’re watered every day or every other day, then they do not develop to their full potential. By deep watering the water gets down to that lower level and the plants are able to “wick” the water into their systems and can go much longer. In some cases this past summer, because we got a lot of rain, we did not utilize our irrigation systems at all in some sites, including Fairmont Parkway for example. That being said, we have also begun utilizing plant material with traditionally strong root systems to begin with such as Bald Cypress, Shumard Oaks, Lorapetelum, Ligustrum, Plumbago, Nandina, Variegated Ginger, and others. A case in point is the Entrance Monument on SH225 @ Underwood. That site has no irrigation. Staff used a water trailer to help it get established, watering periodically with longer intervals. To my knowledge we have not watered that site in over two years, including the drought conditions year before last and it is quite successful. One way to move this program forward is to involve the Parks and Recreation staff in the review process for new building projects in the City, to discuss and make recommendations for drought tolerant plant materials and drip irrigation systems. TxDOT landscape projects utilize a “throwaway” drip irrigation system that is designed to operate for no more than 3 years. Once is fails it is abandoned. Three years of assistance, as long as the plant material is hardy and drought tolerant to begin with, should be enough to establish the permanent planting. The exception is when we have a severe drought and the plants are on a slope or area that doesn’t hold the rainwater when we do get it (i.e. the TxDOT plantings on SH146 that did not survive the big droughts of ‘10 and ’11). I don’t recommend completely abandoning systems; otherwise the TxDOT experience can repeat itself. A Drip Irrigation System is substantially cheaper to install and to maintain than a conventional system. It is a little more labor intensive in that they require constant vigilance. The heads are much smaller and can clog more easily, and they are more susceptible to damage from mowers, weedcutters, vandalism, etc. That being said, the benefits include reduction in wasted runoff water and lower water bills.