Urban Stormwater Master Planning

Title: Urban Stormwater Master Planning

Discussion Group Leaders: Timothy Roane and Kreg Maheu

Main points: stormwater planning and Low-Impact Development (LID)

• DMK is working on a pilot project at Deerborn St. in Englewood, and a lot of the techniques shown here will be implemented.
• Impacts of Development: loss of water retention abilities, pollution.
• Sarasota Bay is officially impaired in nutrients.
• Right now, there is an interlocal stormwater agreement. It assigns responsibility for stormwater management to the county. There seems to be a disconnect between the city's political focus and the county's efforts. We're trying to change that.
• The Sarasota Comprehensive Plan added a LID policy to the Stormwater Tool Box.
• What is LID? It is an approach to stormwater management meant to mimic the hydrology of undeveloped land. The Sarasota LID manual has four parts: Green roofs/cisterns, detention with biofiltration, permeable paving, and stormwater reuse. The manual is constantly being revised.
• LID benefits areas of redevelopment. In downtown SRQ, for example, LID makes better use of its land. It also enhances sustainability.
• LID tools include: bioswales, rain gardens, pervious pavement, inlet filters, vegetation buffers, roof gardens, rain barrels, and solar power. Any design needs to select the tools that best fit the situation.
• Bioswales: indents that collect water and circulate it back up to the adjacent land. They provide biodiversity and habitat in addition to stormwater management.
• Stormwater Reuse: We're using our pipes as cisterns, so that they filter the water before it goes into the bay.
• We have a monitoring plan, to be conducted by Dr. McCord at NCF and the County. That's important, because we know that certain systems have certain effects, but we don't know exactly.
• LID is not necessarily more expensive, because it reduces cost in property acquisition, land clearing, and dedicated stormwater management areas. It frees up space. That's the big selling point of LID; we're giving the city parks, parking lots, aesthetic improvements, educational opportunities, and multi-modal transportation.

Other points, mentioned offhand during the presentation:

• The best way to reduce pollution is to get it at its source, before it gets into the bayou or the bay.
• At Deerborn, LID lets us surpass the water requirements 1½ times.
• We need to add waterfront art; fountains and such for mainstreet, so when you're shopping you know you're in a bayfront community.

Important questions raised:

How are bioswales better than putting in, for example, basic swales and using the extra money for a retrofit?

• The bioswale is like a filtration system on steroids. One difference is, a regular street has a certain capacity. The bioswale is better for a perimeter area, where there's some space. Overall, it is cheaper.

Do pervious pavements keep working over time?

• There's not a whole lot of data, but with proper maintenance they're fine. It's a lot cheaper to maintain the pavement than treat pollution at the bay.

What changes should be made to SRQ policy?

• Change the LID manual to make it more integrated, and get the commissioners on board. We should put credits towards these kinds of technologies. Currently, there's no incentive for developers to use these technologies. Regulation would be a good idea. Also, in some places these technologies are illegal to use!

Areas of general agreement:

There was general consensus that policy integration is important; whether or not the actual master plans are separate or combined, there was an agreement that City policy wasn't integrated with County policy, and that is a problem for planners and civil engineers.

Areas of disagreement:

People disagreed about whether LID should be required, and whether Sarasota's master plan should be integrated into the county's or not. Some were hesitant, saying LID should be “experimented with” whereas others felt that it could only produce positive outcomes and should be required for all new development. Further, the current stormwater master plan, integrating the whole county, is proposed to be cut into individual cities. Some said this was positive, because it would make it easier for Sarasota to take the next steps in implementing LID. Others felt that the limits should be environmentally-defined, and the master plan should include the whole Sarasota watershed. Next steps identified:

The Deerborn project is seen as a next step, as well as revising the LID manual to integrate it better with County policy.